linux/drivers/net/tun.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 Based on 3 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 06:55:06 +00:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* TUN - Universal TUN/TAP device driver.
* Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
*
* $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
*/
/*
* Changes:
*
* Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
* Add TUNSETLINK ioctl to set the link encapsulation
*
* Mark Smith <markzzzsmith@yahoo.com.au>
* Use eth_random_addr() for tap MAC address.
*
* Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
* Fixes in packet dropping, queue length setting and queue wakeup.
* Increased default tx queue length.
* Added ethtool API.
* Minor cleanups
*
* Daniel Podlejski <underley@underley.eu.org>
* Modifications for 2.3.99-pre5 kernel.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define DRV_NAME "tun"
#define DRV_VERSION "1.6"
#define DRV_DESCRIPTION "Universal TUN/TAP device driver"
#define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/miscdevice.h>
#include <linux/ethtool.h>
#include <linux/rtnetlink.h>
#include <linux/compat.h>
#include <linux/if.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_tun.h>
#include <linux/if_vlan.h>
#include <linux/crc32.h>
#include <linux/nsproxy.h>
#include <linux/virtio_net.h>
#include <linux/rcupdate.h>
[NET]: Make the device list and device lookups per namespace. This patch makes most of the generic device layer network namespace safe. This patch makes dev_base_head a network namespace variable, and then it picks up a few associated variables. The functions: dev_getbyhwaddr dev_getfirsthwbytype dev_get_by_flags dev_get_by_name __dev_get_by_name dev_get_by_index __dev_get_by_index dev_ioctl dev_ethtool dev_load wireless_process_ioctl were modified to take a network namespace argument, and deal with it. vlan_ioctl_set and brioctl_set were modified so their hooks will receive a network namespace argument. So basically anthing in the core of the network stack that was affected to by the change of dev_base was modified to handle multiple network namespaces. The rest of the network stack was simply modified to explicitly use &init_net the initial network namespace. This can be fixed when those components of the network stack are modified to handle multiple network namespaces. For now the ifindex generator is left global. Fundametally ifindex numbers are per namespace, or else we will have corner case problems with migration when we get that far. At the same time there are assumptions in the network stack that the ifindex of a network device won't change. Making the ifindex number global seems a good compromise until the network stack can cope with ifindex changes when you change namespaces, and the like. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-17 18:56:21 +00:00
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/rtnetlink.h>
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
#include <net/sock.h>
#include <net/xdp.h>
#include <net/ip_tunnels.h>
#include <linux/seq_file.h>
#include <linux/uio.h>
#include <linux/skb_array.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/proc_fs.h>
static void tun_default_link_ksettings(struct net_device *dev,
struct ethtool_link_ksettings *cmd);
#define TUN_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
/* TUN device flags */
/* IFF_ATTACH_QUEUE is never stored in device flags,
* overload it to mean fasync when stored there.
*/
#define TUN_FASYNC IFF_ATTACH_QUEUE
/* High bits in flags field are unused. */
#define TUN_VNET_LE 0x80000000
#define TUN_VNET_BE 0x40000000
#define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS)
#define GOODCOPY_LEN 128
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
#define FLT_EXACT_COUNT 8
struct tap_filter {
unsigned int count; /* Number of addrs. Zero means disabled */
u32 mask[2]; /* Mask of the hashed addrs */
unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
};
/* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
* to max number of VCPUs in guest. */
#define MAX_TAP_QUEUES 256
#define MAX_TAP_FLOWS 4096
#define TUN_FLOW_EXPIRE (3 * HZ)
/* A tun_file connects an open character device to a tuntap netdevice. It
* also contains all socket related structures (except sock_fprog and tap_filter)
* to serve as one transmit queue for tuntap device. The sock_fprog and
* tap_filter were kept in tun_struct since they were used for filtering for the
* netdevice not for a specific queue (at least I didn't see the requirement for
* this).
*
* RCU usage:
* The tun_file and tun_struct are loosely coupled, the pointer from one to the
* other can only be read while rcu_read_lock or rtnl_lock is held.
*/
struct tun_file {
struct sock sk;
struct socket socket;
struct tun_struct __rcu *tun;
struct fasync_struct *fasync;
/* only used for fasnyc */
unsigned int flags;
union {
u16 queue_index;
unsigned int ifindex;
};
struct napi_struct napi;
net-tun: fix panics at dismantle time syzkaller got crashes at dismantle time [1] It is not correct to test (tun->flags & IFF_NAPI) in tun_napi_disable() and tun_napi_del() : Each tun_file can have different mode, depending on how they were created. Similarly I have changed tun_get_user() and tun_poll_controller() to use the new tfile->napi_enabled boolean. [ 154.331360] BUG: unable to handle kernel NULL pointer dereference at (null) [ 154.339220] IP: [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.344983] PGD 0 [ 154.347009] Oops: 0000 [#1] SMP [ 154.350680] gsmi: Log Shutdown Reason 0x03 [ 154.379572] task: ffff994719150dc0 ti: ffff99475c0ae000 task.ti: ffff99475c0ae000 [ 154.387043] RIP: 0010:[<ffffffff9634cad6>] [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.395232] RSP: 0018:ffff99475c0afce8 EFLAGS: 00010246 [ 154.400542] RAX: ffff994754850ac0 RBX: ffff994753e65408 RCX: ffff994753e65388 [ 154.407666] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff994753e65408 [ 154.414790] RBP: ffff99475c0afce8 R08: 0000000000000000 R09: 0000000000000000 [ 154.421921] R10: ffff99475f6f5910 R11: 0000000000000001 R12: 0000000000000000 [ 154.429044] R13: ffff99417deab668 R14: ffff99417deaa780 R15: ffff99475f45dde0 [ 154.436174] FS: 0000000000000000(0000) GS:ffff994767a00000(0000) knlGS:0000000000000000 [ 154.444249] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 154.449986] CR2: 0000000000000000 CR3: 00000005a8a0e000 CR4: 0000000000022670 [ 154.457110] Stack: [ 154.459120] ffff99475c0afd28 ffffffff9634d614 1000000000000000 0000000000000000 [ 154.466598] ffffe54240000000 ffff994753e65408 ffff994753e653a8 ffff99417deab668 [ 154.474067] ffff99475c0afd48 ffffffff9634d6fd ffff99474c2be678 ffff994753e65398 [ 154.481537] Call Trace: [ 154.483985] [<ffffffff9634d614>] hrtimer_try_to_cancel+0x24/0xf0 [ 154.490074] [<ffffffff9634d6fd>] hrtimer_cancel+0x1d/0x30 [ 154.495563] [<ffffffff96860b3c>] napi_disable+0x3c/0x70 [ 154.500875] [<ffffffff9678ae62>] __tun_detach+0xd2/0x360 [ 154.506272] [<ffffffff9678b117>] tun_chr_close+0x27/0x40 [ 154.511669] [<ffffffff9646ebe6>] __fput+0xd6/0x1e0 [ 154.516548] [<ffffffff9646ed3e>] ____fput+0xe/0x10 [ 154.521429] [<ffffffff963035a2>] task_work_run+0x72/0x90 [ 154.526827] [<ffffffff962e9407>] do_exit+0x317/0xb60 [ 154.531879] [<ffffffff962e9c8f>] do_group_exit+0x3f/0xa0 [ 154.537275] [<ffffffff962e9d07>] SyS_exit_group+0x17/0x20 [ 154.542769] [<ffffffff969784be>] entry_SYSCALL_64_fastpath+0x12/0x17 Fixes: 943170998b20 ("net-tun: enable NAPI for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18 19:12:09 +00:00
bool napi_enabled;
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
bool napi_frags_enabled;
struct mutex napi_mutex; /* Protects access to the above napi */
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
struct list_head next;
struct tun_struct *detached;
struct ptr_ring tx_ring;
struct xdp_rxq_info xdp_rxq;
};
struct tun_page {
struct page *page;
int count;
};
struct tun_flow_entry {
struct hlist_node hash_link;
struct rcu_head rcu;
struct tun_struct *tun;
u32 rxhash;
u32 rps_rxhash;
int queue_index;
unsigned long updated ____cacheline_aligned_in_smp;
};
#define TUN_NUM_FLOW_ENTRIES 1024
#define TUN_MASK_FLOW_ENTRIES (TUN_NUM_FLOW_ENTRIES - 1)
struct tun_prog {
struct rcu_head rcu;
struct bpf_prog *prog;
};
/* Since the socket were moved to tun_file, to preserve the behavior of persist
* device, socket filter, sndbuf and vnet header size were restore when the
* file were attached to a persist device.
*/
struct tun_struct {
struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
unsigned int numqueues;
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
unsigned int flags;
kuid_t owner;
kgid_t group;
struct net_device *dev;
netdev_features_t set_features;
#define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
NETIF_F_TSO6)
int align;
int vnet_hdr_sz;
int sndbuf;
struct tap_filter txflt;
struct sock_fprog fprog;
/* protected by rtnl lock */
bool filter_attached;
u32 msg_enable;
spinlock_t lock;
struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
struct timer_list flow_gc_timer;
unsigned long ageing_time;
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
unsigned int numdisabled;
struct list_head disabled;
tun: fix LSM/SELinux labeling of tun/tap devices This patch corrects some problems with LSM/SELinux that were introduced with the multiqueue patchset. The problem stems from the fact that the multiqueue work changed the relationship between the tun device and its associated socket; before the socket persisted for the life of the device, however after the multiqueue changes the socket only persisted for the life of the userspace connection (fd open). For non-persistent devices this is not an issue, but for persistent devices this can cause the tun device to lose its SELinux label. We correct this problem by adding an opaque LSM security blob to the tun device struct which allows us to have the LSM security state, e.g. SELinux labeling information, persist for the lifetime of the tun device. In the process we tweak the LSM hooks to work with this new approach to TUN device/socket labeling and introduce a new LSM hook, security_tun_dev_attach_queue(), to approve requests to attach to a TUN queue via TUNSETQUEUE. The SELinux code has been adjusted to match the new LSM hooks, the other LSMs do not make use of the LSM TUN controls. This patch makes use of the recently added "tun_socket:attach_queue" permission to restrict access to the TUNSETQUEUE operation. On older SELinux policies which do not define the "tun_socket:attach_queue" permission the access control decision for TUNSETQUEUE will be handled according to the SELinux policy's unknown permission setting. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@parisplace.org> Tested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14 07:12:19 +00:00
void *security;
u32 flow_count;
u32 rx_batched;
atomic_long_t rx_frame_errors;
struct bpf_prog __rcu *xdp_prog;
struct tun_prog __rcu *steering_prog;
struct tun_prog __rcu *filter_prog;
struct ethtool_link_ksettings link_ksettings;
};
struct veth {
__be16 h_vlan_proto;
__be16 h_vlan_TCI;
};
static int tun_napi_receive(struct napi_struct *napi, int budget)
{
struct tun_file *tfile = container_of(napi, struct tun_file, napi);
struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
struct sk_buff_head process_queue;
struct sk_buff *skb;
int received = 0;
__skb_queue_head_init(&process_queue);
spin_lock(&queue->lock);
skb_queue_splice_tail_init(queue, &process_queue);
spin_unlock(&queue->lock);
while (received < budget && (skb = __skb_dequeue(&process_queue))) {
napi_gro_receive(napi, skb);
++received;
}
if (!skb_queue_empty(&process_queue)) {
spin_lock(&queue->lock);
skb_queue_splice(&process_queue, queue);
spin_unlock(&queue->lock);
}
return received;
}
static int tun_napi_poll(struct napi_struct *napi, int budget)
{
unsigned int received;
received = tun_napi_receive(napi, budget);
if (received < budget)
napi_complete_done(napi, received);
return received;
}
static void tun_napi_init(struct tun_struct *tun, struct tun_file *tfile,
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
bool napi_en, bool napi_frags)
{
net-tun: fix panics at dismantle time syzkaller got crashes at dismantle time [1] It is not correct to test (tun->flags & IFF_NAPI) in tun_napi_disable() and tun_napi_del() : Each tun_file can have different mode, depending on how they were created. Similarly I have changed tun_get_user() and tun_poll_controller() to use the new tfile->napi_enabled boolean. [ 154.331360] BUG: unable to handle kernel NULL pointer dereference at (null) [ 154.339220] IP: [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.344983] PGD 0 [ 154.347009] Oops: 0000 [#1] SMP [ 154.350680] gsmi: Log Shutdown Reason 0x03 [ 154.379572] task: ffff994719150dc0 ti: ffff99475c0ae000 task.ti: ffff99475c0ae000 [ 154.387043] RIP: 0010:[<ffffffff9634cad6>] [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.395232] RSP: 0018:ffff99475c0afce8 EFLAGS: 00010246 [ 154.400542] RAX: ffff994754850ac0 RBX: ffff994753e65408 RCX: ffff994753e65388 [ 154.407666] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff994753e65408 [ 154.414790] RBP: ffff99475c0afce8 R08: 0000000000000000 R09: 0000000000000000 [ 154.421921] R10: ffff99475f6f5910 R11: 0000000000000001 R12: 0000000000000000 [ 154.429044] R13: ffff99417deab668 R14: ffff99417deaa780 R15: ffff99475f45dde0 [ 154.436174] FS: 0000000000000000(0000) GS:ffff994767a00000(0000) knlGS:0000000000000000 [ 154.444249] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 154.449986] CR2: 0000000000000000 CR3: 00000005a8a0e000 CR4: 0000000000022670 [ 154.457110] Stack: [ 154.459120] ffff99475c0afd28 ffffffff9634d614 1000000000000000 0000000000000000 [ 154.466598] ffffe54240000000 ffff994753e65408 ffff994753e653a8 ffff99417deab668 [ 154.474067] ffff99475c0afd48 ffffffff9634d6fd ffff99474c2be678 ffff994753e65398 [ 154.481537] Call Trace: [ 154.483985] [<ffffffff9634d614>] hrtimer_try_to_cancel+0x24/0xf0 [ 154.490074] [<ffffffff9634d6fd>] hrtimer_cancel+0x1d/0x30 [ 154.495563] [<ffffffff96860b3c>] napi_disable+0x3c/0x70 [ 154.500875] [<ffffffff9678ae62>] __tun_detach+0xd2/0x360 [ 154.506272] [<ffffffff9678b117>] tun_chr_close+0x27/0x40 [ 154.511669] [<ffffffff9646ebe6>] __fput+0xd6/0x1e0 [ 154.516548] [<ffffffff9646ed3e>] ____fput+0xe/0x10 [ 154.521429] [<ffffffff963035a2>] task_work_run+0x72/0x90 [ 154.526827] [<ffffffff962e9407>] do_exit+0x317/0xb60 [ 154.531879] [<ffffffff962e9c8f>] do_group_exit+0x3f/0xa0 [ 154.537275] [<ffffffff962e9d07>] SyS_exit_group+0x17/0x20 [ 154.542769] [<ffffffff969784be>] entry_SYSCALL_64_fastpath+0x12/0x17 Fixes: 943170998b20 ("net-tun: enable NAPI for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18 19:12:09 +00:00
tfile->napi_enabled = napi_en;
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
tfile->napi_frags_enabled = napi_en && napi_frags;
if (napi_en) {
tun: fix data-race in gro_normal_list() There is a race in the TUN driver between napi_busy_loop and napi_gro_frags. This commit resolves the race by adding the NAPI struct via netif_tx_napi_add, instead of netif_napi_add, which disables polling for the NAPI struct. KCSAN reported: BUG: KCSAN: data-race in gro_normal_list.part.0 / napi_busy_loop write to 0xffff8880b5d474b0 of 4 bytes by task 11205 on cpu 0: gro_normal_list.part.0+0x77/0xb0 net/core/dev.c:5682 gro_normal_list net/core/dev.c:5678 [inline] gro_normal_one net/core/dev.c:5692 [inline] napi_frags_finish net/core/dev.c:5705 [inline] napi_gro_frags+0x625/0x770 net/core/dev.c:5778 tun_get_user+0x2150/0x26a0 drivers/net/tun.c:1976 tun_chr_write_iter+0x79/0xd0 drivers/net/tun.c:2022 call_write_iter include/linux/fs.h:1895 [inline] do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693 do_iter_write fs/read_write.c:970 [inline] do_iter_write+0x13b/0x3c0 fs/read_write.c:951 vfs_writev+0x118/0x1c0 fs/read_write.c:1015 do_writev+0xe3/0x250 fs/read_write.c:1058 __do_sys_writev fs/read_write.c:1131 [inline] __se_sys_writev fs/read_write.c:1128 [inline] __x64_sys_writev+0x4e/0x60 fs/read_write.c:1128 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8880b5d474b0 of 4 bytes by task 11168 on cpu 1: gro_normal_list net/core/dev.c:5678 [inline] napi_busy_loop+0xda/0x4f0 net/core/dev.c:6126 sk_busy_loop include/net/busy_poll.h:108 [inline] __skb_recv_udp+0x4ad/0x560 net/ipv4/udp.c:1689 udpv6_recvmsg+0x29e/0xe90 net/ipv6/udp.c:288 inet6_recvmsg+0xbb/0x240 net/ipv6/af_inet6.c:592 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0x92/0xb0 net/socket.c:885 sock_read_iter+0x15f/0x1e0 net/socket.c:967 call_read_iter include/linux/fs.h:1889 [inline] new_sync_read+0x389/0x4f0 fs/read_write.c:414 __vfs_read+0xb1/0xc0 fs/read_write.c:427 vfs_read fs/read_write.c:461 [inline] vfs_read+0x143/0x2c0 fs/read_write.c:446 ksys_read+0xd5/0x1b0 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x4c/0x60 fs/read_write.c:595 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 11168 Comm: syz-executor.0 Not tainted 5.4.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 943170998b20 ("tun: enable NAPI for TUN/TAP driver") Signed-off-by: Petar Penkov <ppenkov@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-14 17:52:09 +00:00
netif_tx_napi_add(tun->dev, &tfile->napi, tun_napi_poll,
NAPI_POLL_WEIGHT);
napi_enable(&tfile->napi);
}
}
static void tun_napi_disable(struct tun_file *tfile)
{
net-tun: fix panics at dismantle time syzkaller got crashes at dismantle time [1] It is not correct to test (tun->flags & IFF_NAPI) in tun_napi_disable() and tun_napi_del() : Each tun_file can have different mode, depending on how they were created. Similarly I have changed tun_get_user() and tun_poll_controller() to use the new tfile->napi_enabled boolean. [ 154.331360] BUG: unable to handle kernel NULL pointer dereference at (null) [ 154.339220] IP: [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.344983] PGD 0 [ 154.347009] Oops: 0000 [#1] SMP [ 154.350680] gsmi: Log Shutdown Reason 0x03 [ 154.379572] task: ffff994719150dc0 ti: ffff99475c0ae000 task.ti: ffff99475c0ae000 [ 154.387043] RIP: 0010:[<ffffffff9634cad6>] [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.395232] RSP: 0018:ffff99475c0afce8 EFLAGS: 00010246 [ 154.400542] RAX: ffff994754850ac0 RBX: ffff994753e65408 RCX: ffff994753e65388 [ 154.407666] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff994753e65408 [ 154.414790] RBP: ffff99475c0afce8 R08: 0000000000000000 R09: 0000000000000000 [ 154.421921] R10: ffff99475f6f5910 R11: 0000000000000001 R12: 0000000000000000 [ 154.429044] R13: ffff99417deab668 R14: ffff99417deaa780 R15: ffff99475f45dde0 [ 154.436174] FS: 0000000000000000(0000) GS:ffff994767a00000(0000) knlGS:0000000000000000 [ 154.444249] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 154.449986] CR2: 0000000000000000 CR3: 00000005a8a0e000 CR4: 0000000000022670 [ 154.457110] Stack: [ 154.459120] ffff99475c0afd28 ffffffff9634d614 1000000000000000 0000000000000000 [ 154.466598] ffffe54240000000 ffff994753e65408 ffff994753e653a8 ffff99417deab668 [ 154.474067] ffff99475c0afd48 ffffffff9634d6fd ffff99474c2be678 ffff994753e65398 [ 154.481537] Call Trace: [ 154.483985] [<ffffffff9634d614>] hrtimer_try_to_cancel+0x24/0xf0 [ 154.490074] [<ffffffff9634d6fd>] hrtimer_cancel+0x1d/0x30 [ 154.495563] [<ffffffff96860b3c>] napi_disable+0x3c/0x70 [ 154.500875] [<ffffffff9678ae62>] __tun_detach+0xd2/0x360 [ 154.506272] [<ffffffff9678b117>] tun_chr_close+0x27/0x40 [ 154.511669] [<ffffffff9646ebe6>] __fput+0xd6/0x1e0 [ 154.516548] [<ffffffff9646ed3e>] ____fput+0xe/0x10 [ 154.521429] [<ffffffff963035a2>] task_work_run+0x72/0x90 [ 154.526827] [<ffffffff962e9407>] do_exit+0x317/0xb60 [ 154.531879] [<ffffffff962e9c8f>] do_group_exit+0x3f/0xa0 [ 154.537275] [<ffffffff962e9d07>] SyS_exit_group+0x17/0x20 [ 154.542769] [<ffffffff969784be>] entry_SYSCALL_64_fastpath+0x12/0x17 Fixes: 943170998b20 ("net-tun: enable NAPI for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18 19:12:09 +00:00
if (tfile->napi_enabled)
napi_disable(&tfile->napi);
}
static void tun_napi_del(struct tun_file *tfile)
{
net-tun: fix panics at dismantle time syzkaller got crashes at dismantle time [1] It is not correct to test (tun->flags & IFF_NAPI) in tun_napi_disable() and tun_napi_del() : Each tun_file can have different mode, depending on how they were created. Similarly I have changed tun_get_user() and tun_poll_controller() to use the new tfile->napi_enabled boolean. [ 154.331360] BUG: unable to handle kernel NULL pointer dereference at (null) [ 154.339220] IP: [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.344983] PGD 0 [ 154.347009] Oops: 0000 [#1] SMP [ 154.350680] gsmi: Log Shutdown Reason 0x03 [ 154.379572] task: ffff994719150dc0 ti: ffff99475c0ae000 task.ti: ffff99475c0ae000 [ 154.387043] RIP: 0010:[<ffffffff9634cad6>] [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.395232] RSP: 0018:ffff99475c0afce8 EFLAGS: 00010246 [ 154.400542] RAX: ffff994754850ac0 RBX: ffff994753e65408 RCX: ffff994753e65388 [ 154.407666] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff994753e65408 [ 154.414790] RBP: ffff99475c0afce8 R08: 0000000000000000 R09: 0000000000000000 [ 154.421921] R10: ffff99475f6f5910 R11: 0000000000000001 R12: 0000000000000000 [ 154.429044] R13: ffff99417deab668 R14: ffff99417deaa780 R15: ffff99475f45dde0 [ 154.436174] FS: 0000000000000000(0000) GS:ffff994767a00000(0000) knlGS:0000000000000000 [ 154.444249] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 154.449986] CR2: 0000000000000000 CR3: 00000005a8a0e000 CR4: 0000000000022670 [ 154.457110] Stack: [ 154.459120] ffff99475c0afd28 ffffffff9634d614 1000000000000000 0000000000000000 [ 154.466598] ffffe54240000000 ffff994753e65408 ffff994753e653a8 ffff99417deab668 [ 154.474067] ffff99475c0afd48 ffffffff9634d6fd ffff99474c2be678 ffff994753e65398 [ 154.481537] Call Trace: [ 154.483985] [<ffffffff9634d614>] hrtimer_try_to_cancel+0x24/0xf0 [ 154.490074] [<ffffffff9634d6fd>] hrtimer_cancel+0x1d/0x30 [ 154.495563] [<ffffffff96860b3c>] napi_disable+0x3c/0x70 [ 154.500875] [<ffffffff9678ae62>] __tun_detach+0xd2/0x360 [ 154.506272] [<ffffffff9678b117>] tun_chr_close+0x27/0x40 [ 154.511669] [<ffffffff9646ebe6>] __fput+0xd6/0x1e0 [ 154.516548] [<ffffffff9646ed3e>] ____fput+0xe/0x10 [ 154.521429] [<ffffffff963035a2>] task_work_run+0x72/0x90 [ 154.526827] [<ffffffff962e9407>] do_exit+0x317/0xb60 [ 154.531879] [<ffffffff962e9c8f>] do_group_exit+0x3f/0xa0 [ 154.537275] [<ffffffff962e9d07>] SyS_exit_group+0x17/0x20 [ 154.542769] [<ffffffff969784be>] entry_SYSCALL_64_fastpath+0x12/0x17 Fixes: 943170998b20 ("net-tun: enable NAPI for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18 19:12:09 +00:00
if (tfile->napi_enabled)
netif_napi_del(&tfile->napi);
}
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
static bool tun_napi_frags_enabled(const struct tun_file *tfile)
{
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
return tfile->napi_frags_enabled;
}
#ifdef CONFIG_TUN_VNET_CROSS_LE
static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
{
return tun->flags & TUN_VNET_BE ? false :
virtio_legacy_is_little_endian();
}
static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
{
int be = !!(tun->flags & TUN_VNET_BE);
if (put_user(be, argp))
return -EFAULT;
return 0;
}
static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
{
int be;
if (get_user(be, argp))
return -EFAULT;
if (be)
tun->flags |= TUN_VNET_BE;
else
tun->flags &= ~TUN_VNET_BE;
return 0;
}
#else
static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
{
return virtio_legacy_is_little_endian();
}
static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
{
return -EINVAL;
}
static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
{
return -EINVAL;
}
#endif /* CONFIG_TUN_VNET_CROSS_LE */
static inline bool tun_is_little_endian(struct tun_struct *tun)
{
return tun->flags & TUN_VNET_LE ||
tun_legacy_is_little_endian(tun);
}
static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
{
return __virtio16_to_cpu(tun_is_little_endian(tun), val);
}
static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
{
return __cpu_to_virtio16(tun_is_little_endian(tun), val);
}
static inline u32 tun_hashfn(u32 rxhash)
{
return rxhash & TUN_MASK_FLOW_ENTRIES;
}
static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
{
struct tun_flow_entry *e;
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 01:06:00 +00:00
hlist_for_each_entry_rcu(e, head, hash_link) {
if (e->rxhash == rxhash)
return e;
}
return NULL;
}
static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
struct hlist_head *head,
u32 rxhash, u16 queue_index)
{
struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
if (e) {
netif_info(tun, tx_queued, tun->dev,
"create flow: hash %u index %u\n",
rxhash, queue_index);
e->updated = jiffies;
e->rxhash = rxhash;
e->rps_rxhash = 0;
e->queue_index = queue_index;
e->tun = tun;
hlist_add_head_rcu(&e->hash_link, head);
++tun->flow_count;
}
return e;
}
static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
{
netif_info(tun, tx_queued, tun->dev, "delete flow: hash %u index %u\n",
e->rxhash, e->queue_index);
hlist_del_rcu(&e->hash_link);
kfree_rcu(e, rcu);
--tun->flow_count;
}
static void tun_flow_flush(struct tun_struct *tun)
{
int i;
spin_lock_bh(&tun->lock);
for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
struct tun_flow_entry *e;
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 01:06:00 +00:00
struct hlist_node *n;
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 01:06:00 +00:00
hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
tun_flow_delete(tun, e);
}
spin_unlock_bh(&tun->lock);
}
static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
{
int i;
spin_lock_bh(&tun->lock);
for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
struct tun_flow_entry *e;
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 01:06:00 +00:00
struct hlist_node *n;
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 01:06:00 +00:00
hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
if (e->queue_index == queue_index)
tun_flow_delete(tun, e);
}
}
spin_unlock_bh(&tun->lock);
}
treewide: setup_timer() -> timer_setup() This converts all remaining cases of the old setup_timer() API into using timer_setup(), where the callback argument is the structure already holding the struct timer_list. These should have no behavioral changes, since they just change which pointer is passed into the callback with the same available pointers after conversion. It handles the following examples, in addition to some other variations. Casting from unsigned long: void my_callback(unsigned long data) { struct something *ptr = (struct something *)data; ... } ... setup_timer(&ptr->my_timer, my_callback, ptr); and forced object casts: void my_callback(struct something *ptr) { ... } ... setup_timer(&ptr->my_timer, my_callback, (unsigned long)ptr); become: void my_callback(struct timer_list *t) { struct something *ptr = from_timer(ptr, t, my_timer); ... } ... timer_setup(&ptr->my_timer, my_callback, 0); Direct function assignments: void my_callback(unsigned long data) { struct something *ptr = (struct something *)data; ... } ... ptr->my_timer.function = my_callback; have a temporary cast added, along with converting the args: void my_callback(struct timer_list *t) { struct something *ptr = from_timer(ptr, t, my_timer); ... } ... ptr->my_timer.function = (TIMER_FUNC_TYPE)my_callback; And finally, callbacks without a data assignment: void my_callback(unsigned long data) { ... } ... setup_timer(&ptr->my_timer, my_callback, 0); have their argument renamed to verify they're unused during conversion: void my_callback(struct timer_list *unused) { ... } ... timer_setup(&ptr->my_timer, my_callback, 0); The conversion is done with the following Coccinelle script: spatch --very-quiet --all-includes --include-headers \ -I ./arch/x86/include -I ./arch/x86/include/generated \ -I ./include -I ./arch/x86/include/uapi \ -I ./arch/x86/include/generated/uapi -I ./include/uapi \ -I ./include/generated/uapi --include ./include/linux/kconfig.h \ --dir . \ --cocci-file ~/src/data/timer_setup.cocci @fix_address_of@ expression e; @@ setup_timer( -&(e) +&e , ...) // Update any raw setup_timer() usages that have a NULL callback, but // would otherwise match change_timer_function_usage, since the latter // will update all function assignments done in the face of a NULL // function initialization in setup_timer(). @change_timer_function_usage_NULL@ expression _E; identifier _timer; type _cast_data; @@ ( -setup_timer(&_E->_timer, NULL, _E); +timer_setup(&_E->_timer, NULL, 0); | -setup_timer(&_E->_timer, NULL, (_cast_data)_E); +timer_setup(&_E->_timer, NULL, 0); | -setup_timer(&_E._timer, NULL, &_E); +timer_setup(&_E._timer, NULL, 0); | -setup_timer(&_E._timer, NULL, (_cast_data)&_E); +timer_setup(&_E._timer, NULL, 0); ) @change_timer_function_usage@ expression _E; identifier _timer; struct timer_list _stl; identifier _callback; type _cast_func, _cast_data; @@ ( -setup_timer(&_E->_timer, _callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, &_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, &_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)&_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)&_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E._timer, _callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, &_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, &_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)&_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)&_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | _E->_timer@_stl.function = _callback; | _E->_timer@_stl.function = &_callback; | _E->_timer@_stl.function = (_cast_func)_callback; | _E->_timer@_stl.function = (_cast_func)&_callback; | _E._timer@_stl.function = _callback; | _E._timer@_stl.function = &_callback; | _E._timer@_stl.function = (_cast_func)_callback; | _E._timer@_stl.function = (_cast_func)&_callback; ) // callback(unsigned long arg) @change_callback_handle_cast depends on change_timer_function_usage@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _origtype; identifier _origarg; type _handletype; identifier _handle; @@ void _callback( -_origtype _origarg +struct timer_list *t ) { ( ... when != _origarg _handletype *_handle = -(_handletype *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle = -(void *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle; ... when != _handle _handle = -(_handletype *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle; ... when != _handle _handle = -(void *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg ) } // callback(unsigned long arg) without existing variable @change_callback_handle_cast_no_arg depends on change_timer_function_usage && !change_callback_handle_cast@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _origtype; identifier _origarg; type _handletype; @@ void _callback( -_origtype _origarg +struct timer_list *t ) { + _handletype *_origarg = from_timer(_origarg, t, _timer); + ... when != _origarg - (_handletype *)_origarg + _origarg ... when != _origarg } // Avoid already converted callbacks. @match_callback_converted depends on change_timer_function_usage && !change_callback_handle_cast && !change_callback_handle_cast_no_arg@ identifier change_timer_function_usage._callback; identifier t; @@ void _callback(struct timer_list *t) { ... } // callback(struct something *handle) @change_callback_handle_arg depends on change_timer_function_usage && !match_callback_converted && !change_callback_handle_cast && !change_callback_handle_cast_no_arg@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _handletype; identifier _handle; @@ void _callback( -_handletype *_handle +struct timer_list *t ) { + _handletype *_handle = from_timer(_handle, t, _timer); ... } // If change_callback_handle_arg ran on an empty function, remove // the added handler. @unchange_callback_handle_arg depends on change_timer_function_usage && change_callback_handle_arg@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _handletype; identifier _handle; identifier t; @@ void _callback(struct timer_list *t) { - _handletype *_handle = from_timer(_handle, t, _timer); } // We only want to refactor the setup_timer() data argument if we've found // the matching callback. This undoes changes in change_timer_function_usage. @unchange_timer_function_usage depends on change_timer_function_usage && !change_callback_handle_cast && !change_callback_handle_cast_no_arg && !change_callback_handle_arg@ expression change_timer_function_usage._E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type change_timer_function_usage._cast_data; @@ ( -timer_setup(&_E->_timer, _callback, 0); +setup_timer(&_E->_timer, _callback, (_cast_data)_E); | -timer_setup(&_E._timer, _callback, 0); +setup_timer(&_E._timer, _callback, (_cast_data)&_E); ) // If we fixed a callback from a .function assignment, fix the // assignment cast now. @change_timer_function_assignment depends on change_timer_function_usage && (change_callback_handle_cast || change_callback_handle_cast_no_arg || change_callback_handle_arg)@ expression change_timer_function_usage._E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type _cast_func; typedef TIMER_FUNC_TYPE; @@ ( _E->_timer.function = -_callback +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -&_callback +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -(_cast_func)_callback; +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -(_cast_func)&_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -&_callback; +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -(_cast_func)_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -(_cast_func)&_callback +(TIMER_FUNC_TYPE)_callback ; ) // Sometimes timer functions are called directly. Replace matched args. @change_timer_function_calls depends on change_timer_function_usage && (change_callback_handle_cast || change_callback_handle_cast_no_arg || change_callback_handle_arg)@ expression _E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type _cast_data; @@ _callback( ( -(_cast_data)_E +&_E->_timer | -(_cast_data)&_E +&_E._timer | -_E +&_E->_timer ) ) // If a timer has been configured without a data argument, it can be // converted without regard to the callback argument, since it is unused. @match_timer_function_unused_data@ expression _E; identifier _timer; identifier _callback; @@ ( -setup_timer(&_E->_timer, _callback, 0); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, 0L); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, 0UL); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0L); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0UL); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_timer, _callback, 0); +timer_setup(&_timer, _callback, 0); | -setup_timer(&_timer, _callback, 0L); +timer_setup(&_timer, _callback, 0); | -setup_timer(&_timer, _callback, 0UL); +timer_setup(&_timer, _callback, 0); | -setup_timer(_timer, _callback, 0); +timer_setup(_timer, _callback, 0); | -setup_timer(_timer, _callback, 0L); +timer_setup(_timer, _callback, 0); | -setup_timer(_timer, _callback, 0UL); +timer_setup(_timer, _callback, 0); ) @change_callback_unused_data depends on match_timer_function_unused_data@ identifier match_timer_function_unused_data._callback; type _origtype; identifier _origarg; @@ void _callback( -_origtype _origarg +struct timer_list *unused ) { ... when != _origarg } Signed-off-by: Kees Cook <keescook@chromium.org>
2017-10-16 21:43:17 +00:00
static void tun_flow_cleanup(struct timer_list *t)
{
treewide: setup_timer() -> timer_setup() This converts all remaining cases of the old setup_timer() API into using timer_setup(), where the callback argument is the structure already holding the struct timer_list. These should have no behavioral changes, since they just change which pointer is passed into the callback with the same available pointers after conversion. It handles the following examples, in addition to some other variations. Casting from unsigned long: void my_callback(unsigned long data) { struct something *ptr = (struct something *)data; ... } ... setup_timer(&ptr->my_timer, my_callback, ptr); and forced object casts: void my_callback(struct something *ptr) { ... } ... setup_timer(&ptr->my_timer, my_callback, (unsigned long)ptr); become: void my_callback(struct timer_list *t) { struct something *ptr = from_timer(ptr, t, my_timer); ... } ... timer_setup(&ptr->my_timer, my_callback, 0); Direct function assignments: void my_callback(unsigned long data) { struct something *ptr = (struct something *)data; ... } ... ptr->my_timer.function = my_callback; have a temporary cast added, along with converting the args: void my_callback(struct timer_list *t) { struct something *ptr = from_timer(ptr, t, my_timer); ... } ... ptr->my_timer.function = (TIMER_FUNC_TYPE)my_callback; And finally, callbacks without a data assignment: void my_callback(unsigned long data) { ... } ... setup_timer(&ptr->my_timer, my_callback, 0); have their argument renamed to verify they're unused during conversion: void my_callback(struct timer_list *unused) { ... } ... timer_setup(&ptr->my_timer, my_callback, 0); The conversion is done with the following Coccinelle script: spatch --very-quiet --all-includes --include-headers \ -I ./arch/x86/include -I ./arch/x86/include/generated \ -I ./include -I ./arch/x86/include/uapi \ -I ./arch/x86/include/generated/uapi -I ./include/uapi \ -I ./include/generated/uapi --include ./include/linux/kconfig.h \ --dir . \ --cocci-file ~/src/data/timer_setup.cocci @fix_address_of@ expression e; @@ setup_timer( -&(e) +&e , ...) // Update any raw setup_timer() usages that have a NULL callback, but // would otherwise match change_timer_function_usage, since the latter // will update all function assignments done in the face of a NULL // function initialization in setup_timer(). @change_timer_function_usage_NULL@ expression _E; identifier _timer; type _cast_data; @@ ( -setup_timer(&_E->_timer, NULL, _E); +timer_setup(&_E->_timer, NULL, 0); | -setup_timer(&_E->_timer, NULL, (_cast_data)_E); +timer_setup(&_E->_timer, NULL, 0); | -setup_timer(&_E._timer, NULL, &_E); +timer_setup(&_E._timer, NULL, 0); | -setup_timer(&_E._timer, NULL, (_cast_data)&_E); +timer_setup(&_E._timer, NULL, 0); ) @change_timer_function_usage@ expression _E; identifier _timer; struct timer_list _stl; identifier _callback; type _cast_func, _cast_data; @@ ( -setup_timer(&_E->_timer, _callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, &_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, &_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)&_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)&_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E._timer, _callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, &_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, &_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)&_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)&_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | _E->_timer@_stl.function = _callback; | _E->_timer@_stl.function = &_callback; | _E->_timer@_stl.function = (_cast_func)_callback; | _E->_timer@_stl.function = (_cast_func)&_callback; | _E._timer@_stl.function = _callback; | _E._timer@_stl.function = &_callback; | _E._timer@_stl.function = (_cast_func)_callback; | _E._timer@_stl.function = (_cast_func)&_callback; ) // callback(unsigned long arg) @change_callback_handle_cast depends on change_timer_function_usage@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _origtype; identifier _origarg; type _handletype; identifier _handle; @@ void _callback( -_origtype _origarg +struct timer_list *t ) { ( ... when != _origarg _handletype *_handle = -(_handletype *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle = -(void *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle; ... when != _handle _handle = -(_handletype *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle; ... when != _handle _handle = -(void *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg ) } // callback(unsigned long arg) without existing variable @change_callback_handle_cast_no_arg depends on change_timer_function_usage && !change_callback_handle_cast@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _origtype; identifier _origarg; type _handletype; @@ void _callback( -_origtype _origarg +struct timer_list *t ) { + _handletype *_origarg = from_timer(_origarg, t, _timer); + ... when != _origarg - (_handletype *)_origarg + _origarg ... when != _origarg } // Avoid already converted callbacks. @match_callback_converted depends on change_timer_function_usage && !change_callback_handle_cast && !change_callback_handle_cast_no_arg@ identifier change_timer_function_usage._callback; identifier t; @@ void _callback(struct timer_list *t) { ... } // callback(struct something *handle) @change_callback_handle_arg depends on change_timer_function_usage && !match_callback_converted && !change_callback_handle_cast && !change_callback_handle_cast_no_arg@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _handletype; identifier _handle; @@ void _callback( -_handletype *_handle +struct timer_list *t ) { + _handletype *_handle = from_timer(_handle, t, _timer); ... } // If change_callback_handle_arg ran on an empty function, remove // the added handler. @unchange_callback_handle_arg depends on change_timer_function_usage && change_callback_handle_arg@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _handletype; identifier _handle; identifier t; @@ void _callback(struct timer_list *t) { - _handletype *_handle = from_timer(_handle, t, _timer); } // We only want to refactor the setup_timer() data argument if we've found // the matching callback. This undoes changes in change_timer_function_usage. @unchange_timer_function_usage depends on change_timer_function_usage && !change_callback_handle_cast && !change_callback_handle_cast_no_arg && !change_callback_handle_arg@ expression change_timer_function_usage._E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type change_timer_function_usage._cast_data; @@ ( -timer_setup(&_E->_timer, _callback, 0); +setup_timer(&_E->_timer, _callback, (_cast_data)_E); | -timer_setup(&_E._timer, _callback, 0); +setup_timer(&_E._timer, _callback, (_cast_data)&_E); ) // If we fixed a callback from a .function assignment, fix the // assignment cast now. @change_timer_function_assignment depends on change_timer_function_usage && (change_callback_handle_cast || change_callback_handle_cast_no_arg || change_callback_handle_arg)@ expression change_timer_function_usage._E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type _cast_func; typedef TIMER_FUNC_TYPE; @@ ( _E->_timer.function = -_callback +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -&_callback +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -(_cast_func)_callback; +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -(_cast_func)&_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -&_callback; +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -(_cast_func)_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -(_cast_func)&_callback +(TIMER_FUNC_TYPE)_callback ; ) // Sometimes timer functions are called directly. Replace matched args. @change_timer_function_calls depends on change_timer_function_usage && (change_callback_handle_cast || change_callback_handle_cast_no_arg || change_callback_handle_arg)@ expression _E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type _cast_data; @@ _callback( ( -(_cast_data)_E +&_E->_timer | -(_cast_data)&_E +&_E._timer | -_E +&_E->_timer ) ) // If a timer has been configured without a data argument, it can be // converted without regard to the callback argument, since it is unused. @match_timer_function_unused_data@ expression _E; identifier _timer; identifier _callback; @@ ( -setup_timer(&_E->_timer, _callback, 0); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, 0L); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, 0UL); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0L); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0UL); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_timer, _callback, 0); +timer_setup(&_timer, _callback, 0); | -setup_timer(&_timer, _callback, 0L); +timer_setup(&_timer, _callback, 0); | -setup_timer(&_timer, _callback, 0UL); +timer_setup(&_timer, _callback, 0); | -setup_timer(_timer, _callback, 0); +timer_setup(_timer, _callback, 0); | -setup_timer(_timer, _callback, 0L); +timer_setup(_timer, _callback, 0); | -setup_timer(_timer, _callback, 0UL); +timer_setup(_timer, _callback, 0); ) @change_callback_unused_data depends on match_timer_function_unused_data@ identifier match_timer_function_unused_data._callback; type _origtype; identifier _origarg; @@ void _callback( -_origtype _origarg +struct timer_list *unused ) { ... when != _origarg } Signed-off-by: Kees Cook <keescook@chromium.org>
2017-10-16 21:43:17 +00:00
struct tun_struct *tun = from_timer(tun, t, flow_gc_timer);
unsigned long delay = tun->ageing_time;
unsigned long next_timer = jiffies + delay;
unsigned long count = 0;
int i;
spin_lock(&tun->lock);
for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
struct tun_flow_entry *e;
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 01:06:00 +00:00
struct hlist_node *n;
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 01:06:00 +00:00
hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
unsigned long this_timer;
this_timer = e->updated + delay;
if (time_before_eq(this_timer, jiffies)) {
tun_flow_delete(tun, e);
continue;
}
count++;
if (time_before(this_timer, next_timer))
next_timer = this_timer;
}
}
if (count)
mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
spin_unlock(&tun->lock);
}
tuntap: dont use skb after netif_rx_ni(skb) On Wed, 2012-12-12 at 23:16 -0500, Dave Jones wrote: > Since todays net merge, I see this when I start openvpn.. > > general protection fault: 0000 [#1] PREEMPT SMP > Modules linked in: ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack nf_conntrack ip6table_filter ip6_tables xfs iTCO_wdt iTCO_vendor_support snd_emu10k1 snd_util_mem snd_ac97_codec coretemp ac97_bus microcode snd_hwdep snd_seq pcspkr snd_pcm snd_page_alloc snd_timer lpc_ich i2c_i801 snd_rawmidi mfd_core snd_seq_device snd e1000e soundcore emu10k1_gp gameport i82975x_edac edac_core vhost_net tun macvtap macvlan kvm_intel kvm binfmt_misc nfsd auth_rpcgss nfs_acl lockd sunrpc btrfs libcrc32c zlib_deflate firewire_ohci sata_sil firewire_core crc_itu_t radeon i2c_algo_bit drm_kms_helper ttm drm i2c_core floppy > CPU 0 > Pid: 1381, comm: openvpn Not tainted 3.7.0+ #14 /D975XBX > RIP: 0010:[<ffffffff815b54a4>] [<ffffffff815b54a4>] skb_flow_dissect+0x314/0x3e0 > RSP: 0018:ffff88007d0d9c48 EFLAGS: 00010206 > RAX: 000000000000055d RBX: 6b6b6b6b6b6b6b4b RCX: 1471030a0180040a > RDX: 0000000000000005 RSI: 00000000ffffffe0 RDI: ffff8800ba83fa80 > RBP: ffff88007d0d9cb8 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000101 R12: ffff8800ba83fa80 > R13: 0000000000000008 R14: ffff88007d0d9cc8 R15: ffff8800ba83fa80 > FS: 00007f6637104800(0000) GS:ffff8800bf600000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f563f5b01c4 CR3: 000000007d140000 CR4: 00000000000007f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process openvpn (pid: 1381, threadinfo ffff88007d0d8000, task ffff8800a540cd60) > Stack: > ffff8800ba83fa80 0000000000000296 0000000000000000 0000000000000000 > ffff88007d0d9cc8 ffffffff815bcff4 ffff88007d0d9ce8 ffffffff815b1831 > ffff88007d0d9ca8 00000000703f6364 ffff8800ba83fa80 0000000000000000 > Call Trace: > [<ffffffff815bcff4>] ? netif_rx+0x114/0x4c0 > [<ffffffff815b1831>] ? skb_copy_datagram_from_iovec+0x61/0x290 > [<ffffffff815b672a>] __skb_get_rxhash+0x1a/0xd0 > [<ffffffffa03b9538>] tun_get_user+0x418/0x810 [tun] > [<ffffffff8135f468>] ? delay_tsc+0x98/0xf0 > [<ffffffff8109605c>] ? __rcu_read_unlock+0x5c/0xa0 > [<ffffffffa03b9a41>] tun_chr_aio_write+0x81/0xb0 [tun] > [<ffffffff81145011>] ? __buffer_unlock_commit+0x41/0x50 > [<ffffffff811db917>] do_sync_write+0xa7/0xe0 > [<ffffffff811dc01f>] vfs_write+0xaf/0x190 > [<ffffffff811dc375>] sys_write+0x55/0xa0 > [<ffffffff81705540>] tracesys+0xdd/0xe2 > Code: 41 8b 44 24 68 41 2b 44 24 6c 01 de 29 f0 83 f8 03 0f 8e a0 00 00 00 48 63 de 49 03 9c 24 e0 00 00 00 48 85 db 0f 84 72 fe ff ff <8b> 03 41 89 46 08 b8 01 00 00 00 e9 43 fd ff ff 0f 1f 40 00 48 > RIP [<ffffffff815b54a4>] skb_flow_dissect+0x314/0x3e0 > RSP <ffff88007d0d9c48> > ---[ end trace 6d42c834c72c002e ]--- > > > Faulting instruction is > > 0: 8b 03 mov (%rbx),%eax > > rbx is slab poison (-20) so this looks like a use-after-free here... > > flow->ports = *ports; > 314: 8b 03 mov (%rbx),%eax > 316: 41 89 46 08 mov %eax,0x8(%r14) > > in the inlined skb_header_pointer in skb_flow_dissect > > Dave > commit 96442e4242 (tuntap: choose the txq based on rxq) added a use after free. Cache rxhash in a temp variable before calling netif_rx_ni() Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jason Wang <jasowang@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-12 19:22:57 +00:00
static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
struct tun_file *tfile)
{
struct hlist_head *head;
struct tun_flow_entry *e;
unsigned long delay = tun->ageing_time;
u16 queue_index = tfile->queue_index;
head = &tun->flows[tun_hashfn(rxhash)];
rcu_read_lock();
e = tun_flow_find(head, rxhash);
if (likely(e)) {
/* TODO: keep queueing to old queue until it's empty? */
if (READ_ONCE(e->queue_index) != queue_index)
WRITE_ONCE(e->queue_index, queue_index);
if (e->updated != jiffies)
e->updated = jiffies;
sock_rps_record_flow_hash(e->rps_rxhash);
} else {
spin_lock_bh(&tun->lock);
if (!tun_flow_find(head, rxhash) &&
tun->flow_count < MAX_TAP_FLOWS)
tun_flow_create(tun, head, rxhash, queue_index);
if (!timer_pending(&tun->flow_gc_timer))
mod_timer(&tun->flow_gc_timer,
round_jiffies_up(jiffies + delay));
spin_unlock_bh(&tun->lock);
}
rcu_read_unlock();
}
/* Save the hash received in the stack receive path and update the
* flow_hash table accordingly.
*/
static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
{
if (unlikely(e->rps_rxhash != hash))
e->rps_rxhash = hash;
}
/* We try to identify a flow through its rxhash. The reason that
* we do not check rxq no. is because some cards(e.g 82599), chooses
* the rxq based on the txq where the last packet of the flow comes. As
* the userspace application move between processors, we may get a
* different rxq no. here.
*/
static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb)
{
struct tun_flow_entry *e;
u32 txq = 0;
u32 numqueues = 0;
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-23 21:07:29 +00:00
numqueues = READ_ONCE(tun->numqueues);
txq = __skb_get_hash_symmetric(skb);
e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
if (e) {
tun_flow_save_rps_rxhash(e, txq);
txq = e->queue_index;
} else {
/* use multiply and shift instead of expensive divide */
txq = ((u64)txq * numqueues) >> 32;
}
return txq;
}
static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb)
{
struct tun_prog *prog;
u32 numqueues;
u16 ret = 0;
numqueues = READ_ONCE(tun->numqueues);
if (!numqueues)
return 0;
prog = rcu_dereference(tun->steering_prog);
if (prog)
ret = bpf_prog_run_clear_cb(prog->prog, skb);
return ret % numqueues;
}
static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
struct net_device *sb_dev)
{
struct tun_struct *tun = netdev_priv(dev);
u16 ret;
rcu_read_lock();
if (rcu_dereference(tun->steering_prog))
ret = tun_ebpf_select_queue(tun, skb);
else
ret = tun_automq_select_queue(tun, skb);
rcu_read_unlock();
return ret;
}
static inline bool tun_not_capable(struct tun_struct *tun)
{
const struct cred *cred = current_cred();
struct net *net = dev_net(tun->dev);
return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
(gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
!ns_capable(net->user_ns, CAP_NET_ADMIN);
}
static void tun_set_real_num_queues(struct tun_struct *tun)
{
netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
}
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
{
tfile->detached = tun;
list_add_tail(&tfile->next, &tun->disabled);
++tun->numdisabled;
}
static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
{
struct tun_struct *tun = tfile->detached;
tfile->detached = NULL;
list_del_init(&tfile->next);
--tun->numdisabled;
return tun;
}
void tun_ptr_free(void *ptr)
{
if (!ptr)
return;
if (tun_is_xdp_frame(ptr)) {
struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
xdp: transition into using xdp_frame for return API Changing API xdp_return_frame() to take struct xdp_frame as argument, seems like a natural choice. But there are some subtle performance details here that needs extra care, which is a deliberate choice. When de-referencing xdp_frame on a remote CPU during DMA-TX completion, result in the cache-line is change to "Shared" state. Later when the page is reused for RX, then this xdp_frame cache-line is written, which change the state to "Modified". This situation already happens (naturally) for, virtio_net, tun and cpumap as the xdp_frame pointer is the queued object. In tun and cpumap, the ptr_ring is used for efficiently transferring cache-lines (with pointers) between CPUs. Thus, the only option is to de-referencing xdp_frame. It is only the ixgbe driver that had an optimization, in which it can avoid doing the de-reference of xdp_frame. The driver already have TX-ring queue, which (in case of remote DMA-TX completion) have to be transferred between CPUs anyhow. In this data area, we stored a struct xdp_mem_info and a data pointer, which allowed us to avoid de-referencing xdp_frame. To compensate for this, a prefetchw is used for telling the cache coherency protocol about our access pattern. My benchmarks show that this prefetchw is enough to compensate the ixgbe driver. V7: Adjust for commit d9314c474d4f ("i40e: add support for XDP_REDIRECT") V8: Adjust for commit bd658dda4237 ("net/mlx5e: Separate dma base address and offset in dma_sync call") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 14:46:32 +00:00
xdp_return_frame(xdpf);
} else {
__skb_array_destroy_skb(ptr);
}
}
EXPORT_SYMBOL_GPL(tun_ptr_free);
static void tun_queue_purge(struct tun_file *tfile)
{
void *ptr;
while ((ptr = ptr_ring_consume(&tfile->tx_ring)) != NULL)
tun_ptr_free(ptr);
skb_queue_purge(&tfile->sk.sk_write_queue);
skb_queue_purge(&tfile->sk.sk_error_queue);
}
static void __tun_detach(struct tun_file *tfile, bool clean)
{
struct tun_file *ntfile;
struct tun_struct *tun;
tun = rtnl_dereference(tfile->tun);
if (tun && clean) {
tun_napi_disable(tfile);
tun_napi_del(tfile);
}
if (tun && !tfile->detached) {
u16 index = tfile->queue_index;
BUG_ON(index >= tun->numqueues);
rcu_assign_pointer(tun->tfiles[index],
tun->tfiles[tun->numqueues - 1]);
ntfile = rtnl_dereference(tun->tfiles[index]);
ntfile->queue_index = index;
rcu_assign_pointer(tun->tfiles[tun->numqueues - 1],
NULL);
--tun->numqueues;
if (clean) {
RCU_INIT_POINTER(tfile->tun, NULL);
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
sock_put(&tfile->sk);
} else
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
tun_disable_queue(tun, tfile);
synchronize_net();
tun_flow_delete_by_queue(tun, tun->numqueues + 1);
/* Drop read queue */
tun_queue_purge(tfile);
tun_set_real_num_queues(tun);
} else if (tfile->detached && clean) {
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
tun = tun_enable_queue(tfile);
sock_put(&tfile->sk);
}
if (clean) {
if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
netif_carrier_off(tun->dev);
if (!(tun->flags & IFF_PERSIST) &&
tun->dev->reg_state == NETREG_REGISTERED)
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
unregister_netdevice(tun->dev);
}
if (tun)
xdp_rxq_info_unreg(&tfile->xdp_rxq);
ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
sock_put(&tfile->sk);
}
}
static void tun_detach(struct tun_file *tfile, bool clean)
{
struct tun_struct *tun;
struct net_device *dev;
rtnl_lock();
tun = rtnl_dereference(tfile->tun);
dev = tun ? tun->dev : NULL;
__tun_detach(tfile, clean);
if (dev)
netdev_state_change(dev);
rtnl_unlock();
}
static void tun_detach_all(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
struct tun_file *tfile, *tmp;
int i, n = tun->numqueues;
for (i = 0; i < n; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
BUG_ON(!tfile);
tun_napi_disable(tfile);
tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
tfile->socket.sk->sk_data_ready(tfile->socket.sk);
RCU_INIT_POINTER(tfile->tun, NULL);
--tun->numqueues;
}
list_for_each_entry(tfile, &tun->disabled, next) {
tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
tfile->socket.sk->sk_data_ready(tfile->socket.sk);
RCU_INIT_POINTER(tfile->tun, NULL);
}
BUG_ON(tun->numqueues != 0);
synchronize_net();
for (i = 0; i < n; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
tun_napi_del(tfile);
/* Drop read queue */
tun_queue_purge(tfile);
xdp_rxq_info_unreg(&tfile->xdp_rxq);
sock_put(&tfile->sk);
}
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
tun_enable_queue(tfile);
tun_queue_purge(tfile);
xdp_rxq_info_unreg(&tfile->xdp_rxq);
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
sock_put(&tfile->sk);
}
BUG_ON(tun->numdisabled != 0);
if (tun->flags & IFF_PERSIST)
module_put(THIS_MODULE);
}
static int tun_attach(struct tun_struct *tun, struct file *file,
tun: fix use-after-free when register netdev failed I got a UAF repport in tun driver when doing fuzzy test: [ 466.269490] ================================================================== [ 466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0 [ 466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699 [ 466.271810] [ 466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427 [ 466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 466.271838] Call Trace: [ 466.271858] dump_stack+0xca/0x13e [ 466.271871] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271890] print_address_description+0x79/0x440 [ 466.271906] ? vprintk_func+0x5e/0xf0 [ 466.271920] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271935] __kasan_report+0x15c/0x1df [ 466.271958] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271976] kasan_report+0xe/0x20 [ 466.271987] tun_chr_read_iter+0x2ca/0x2d0 [ 466.272013] do_iter_readv_writev+0x4b7/0x740 [ 466.272032] ? default_llseek+0x2d0/0x2d0 [ 466.272072] do_iter_read+0x1c5/0x5e0 [ 466.272110] vfs_readv+0x108/0x180 [ 466.299007] ? compat_rw_copy_check_uvector+0x440/0x440 [ 466.299020] ? fsnotify+0x888/0xd50 [ 466.299040] ? __fsnotify_parent+0xd0/0x350 [ 466.299064] ? fsnotify_first_mark+0x1e0/0x1e0 [ 466.304548] ? vfs_write+0x264/0x510 [ 466.304569] ? ksys_write+0x101/0x210 [ 466.304591] ? do_preadv+0x116/0x1a0 [ 466.304609] do_preadv+0x116/0x1a0 [ 466.309829] do_syscall_64+0xc8/0x600 [ 466.309849] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.309861] RIP: 0033:0x4560f9 [ 466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127 [ 466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9 [ 466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003 [ 466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000 [ 466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10 [ 466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000 [ 466.323057] [ 466.323064] Allocated by task 2605: [ 466.335165] save_stack+0x19/0x80 [ 466.336240] __kasan_kmalloc.constprop.8+0xa0/0xd0 [ 466.337755] kmem_cache_alloc+0xe8/0x320 [ 466.339050] getname_flags+0xca/0x560 [ 466.340229] user_path_at_empty+0x2c/0x50 [ 466.341508] vfs_statx+0xe6/0x190 [ 466.342619] __do_sys_newstat+0x81/0x100 [ 466.343908] do_syscall_64+0xc8/0x600 [ 466.345303] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.347034] [ 466.347517] Freed by task 2605: [ 466.348471] save_stack+0x19/0x80 [ 466.349476] __kasan_slab_free+0x12e/0x180 [ 466.350726] kmem_cache_free+0xc8/0x430 [ 466.351874] putname+0xe2/0x120 [ 466.352921] filename_lookup+0x257/0x3e0 [ 466.354319] vfs_statx+0xe6/0x190 [ 466.355498] __do_sys_newstat+0x81/0x100 [ 466.356889] do_syscall_64+0xc8/0x600 [ 466.358037] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.359567] [ 466.360050] The buggy address belongs to the object at ffff888372139100 [ 466.360050] which belongs to the cache names_cache of size 4096 [ 466.363735] The buggy address is located 336 bytes inside of [ 466.363735] 4096-byte region [ffff888372139100, ffff88837213a100) [ 466.367179] The buggy address belongs to the page: [ 466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0 [ 466.371582] flags: 0x2fffff80010200(slab|head) [ 466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00 [ 466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 [ 466.377778] page dumped because: kasan: bad access detected [ 466.379730] [ 466.380288] Memory state around the buggy address: [ 466.381844] ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.384009] ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.388257] ^ [ 466.390234] ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.392512] ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.394667] ================================================================== tun_chr_read_iter() accessed the memory which freed by free_netdev() called by tun_set_iff(): CPUA CPUB tun_set_iff() alloc_netdev_mqs() tun_attach() tun_chr_read_iter() tun_get() tun_do_read() tun_ring_recv() register_netdevice() <-- inject error goto err_detach tun_detach_all() <-- set RCV_SHUTDOWN free_netdev() <-- called from err_free_dev path netdev_freemem() <-- free the memory without check refcount (In this path, the refcount cannot prevent freeing the memory of dev, and the memory will be used by dev_put() called by tun_chr_read_iter() on CPUB.) (Break from tun_ring_recv(), because RCV_SHUTDOWN is set) tun_put() dev_put() <-- use the memory freed by netdev_freemem() Put the publishing of tfile->tun after register_netdevice(), so tun_get() won't get the tun pointer that freed by err_detach path if register_netdevice() failed. Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice") Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-10 10:56:57 +00:00
bool skip_filter, bool napi, bool napi_frags,
bool publish_tun)
{
struct tun_file *tfile = file->private_data;
struct net_device *dev = tun->dev;
int err;
tun: fix LSM/SELinux labeling of tun/tap devices This patch corrects some problems with LSM/SELinux that were introduced with the multiqueue patchset. The problem stems from the fact that the multiqueue work changed the relationship between the tun device and its associated socket; before the socket persisted for the life of the device, however after the multiqueue changes the socket only persisted for the life of the userspace connection (fd open). For non-persistent devices this is not an issue, but for persistent devices this can cause the tun device to lose its SELinux label. We correct this problem by adding an opaque LSM security blob to the tun device struct which allows us to have the LSM security state, e.g. SELinux labeling information, persist for the lifetime of the tun device. In the process we tweak the LSM hooks to work with this new approach to TUN device/socket labeling and introduce a new LSM hook, security_tun_dev_attach_queue(), to approve requests to attach to a TUN queue via TUNSETQUEUE. The SELinux code has been adjusted to match the new LSM hooks, the other LSMs do not make use of the LSM TUN controls. This patch makes use of the recently added "tun_socket:attach_queue" permission to restrict access to the TUNSETQUEUE operation. On older SELinux policies which do not define the "tun_socket:attach_queue" permission the access control decision for TUNSETQUEUE will be handled according to the SELinux policy's unknown permission setting. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@parisplace.org> Tested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14 07:12:19 +00:00
err = security_tun_dev_attach(tfile->socket.sk, tun->security);
if (err < 0)
goto out;
err = -EINVAL;
if (rtnl_dereference(tfile->tun) && !tfile->detached)
goto out;
err = -EBUSY;
if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
goto out;
err = -E2BIG;
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
if (!tfile->detached &&
tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
goto out;
err = 0;
/* Re-attach the filter to persist device */
if (!skip_filter && (tun->filter_attached == true)) {
lock_sock(tfile->socket.sk);
err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
release_sock(tfile->socket.sk);
if (!err)
goto out;
}
if (!tfile->detached &&
ptr_ring_resize(&tfile->tx_ring, dev->tx_queue_len,
GFP_KERNEL, tun_ptr_free)) {
err = -ENOMEM;
goto out;
}
tfile->queue_index = tun->numqueues;
tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;
if (tfile->detached) {
/* Re-attach detached tfile, updating XDP queue_index */
WARN_ON(!xdp_rxq_info_is_reg(&tfile->xdp_rxq));
if (tfile->xdp_rxq.queue_index != tfile->queue_index)
tfile->xdp_rxq.queue_index = tfile->queue_index;
} else {
/* Setup XDP RX-queue info, for new tfile getting attached */
err = xdp_rxq_info_reg(&tfile->xdp_rxq,
tun->dev, tfile->queue_index);
if (err < 0)
goto out;
xdp: rhashtable with allocator ID to pointer mapping Use the IDA infrastructure for getting a cyclic increasing ID number, that is used for keeping track of each registered allocator per RX-queue xdp_rxq_info. Instead of using the IDR infrastructure, which uses a radix tree, use a dynamic rhashtable, for creating ID to pointer lookup table, because this is faster. The problem that is being solved here is that, the xdp_rxq_info pointer (stored in xdp_buff) cannot be used directly, as the guaranteed lifetime is too short. The info is needed on a (potentially) remote CPU during DMA-TX completion time . In an xdp_frame the xdp_mem_info is stored, when it got converted from an xdp_buff, which is sufficient for the simple page refcnt based recycle schemes. For more advanced allocators there is a need to store a pointer to the registered allocator. Thus, there is a need to guard the lifetime or validity of the allocator pointer, which is done through this rhashtable ID map to pointer. The removal and validity of of the allocator and helper struct xdp_mem_allocator is guarded by RCU. The allocator will be created by the driver, and registered with xdp_rxq_info_reg_mem_model(). It is up-to debate who is responsible for freeing the allocator pointer or invoking the allocator destructor function. In any case, this must happen via RCU freeing. Use the IDA infrastructure for getting a cyclic increasing ID number, that is used for keeping track of each registered allocator per RX-queue xdp_rxq_info. V4: Per req of Jason Wang - Use xdp_rxq_info_reg_mem_model() in all drivers implementing XDP_REDIRECT, even-though it's not strictly necessary when allocator==NULL for type MEM_TYPE_PAGE_SHARED (given it's zero). V6: Per req of Alex Duyck - Introduce rhashtable_lookup() call in later patch V8: Address sparse should be static warnings (from kbuild test robot) Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 14:46:12 +00:00
err = xdp_rxq_info_reg_mem_model(&tfile->xdp_rxq,
MEM_TYPE_PAGE_SHARED, NULL);
if (err < 0) {
xdp_rxq_info_unreg(&tfile->xdp_rxq);
goto out;
}
err = 0;
}
if (tfile->detached) {
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
tun_enable_queue(tfile);
} else {
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
sock_hold(&tfile->sk);
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
tun_napi_init(tun, tfile, napi, napi_frags);
}
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
if (rtnl_dereference(tun->xdp_prog))
sock_set_flag(&tfile->sk, SOCK_XDP);
/* device is allowed to go away first, so no need to hold extra
* refcnt.
*/
/* Publish tfile->tun and tun->tfiles only after we've fully
* initialized tfile; otherwise we risk using half-initialized
* object.
*/
tun: fix use-after-free when register netdev failed I got a UAF repport in tun driver when doing fuzzy test: [ 466.269490] ================================================================== [ 466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0 [ 466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699 [ 466.271810] [ 466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427 [ 466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 466.271838] Call Trace: [ 466.271858] dump_stack+0xca/0x13e [ 466.271871] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271890] print_address_description+0x79/0x440 [ 466.271906] ? vprintk_func+0x5e/0xf0 [ 466.271920] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271935] __kasan_report+0x15c/0x1df [ 466.271958] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271976] kasan_report+0xe/0x20 [ 466.271987] tun_chr_read_iter+0x2ca/0x2d0 [ 466.272013] do_iter_readv_writev+0x4b7/0x740 [ 466.272032] ? default_llseek+0x2d0/0x2d0 [ 466.272072] do_iter_read+0x1c5/0x5e0 [ 466.272110] vfs_readv+0x108/0x180 [ 466.299007] ? compat_rw_copy_check_uvector+0x440/0x440 [ 466.299020] ? fsnotify+0x888/0xd50 [ 466.299040] ? __fsnotify_parent+0xd0/0x350 [ 466.299064] ? fsnotify_first_mark+0x1e0/0x1e0 [ 466.304548] ? vfs_write+0x264/0x510 [ 466.304569] ? ksys_write+0x101/0x210 [ 466.304591] ? do_preadv+0x116/0x1a0 [ 466.304609] do_preadv+0x116/0x1a0 [ 466.309829] do_syscall_64+0xc8/0x600 [ 466.309849] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.309861] RIP: 0033:0x4560f9 [ 466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127 [ 466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9 [ 466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003 [ 466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000 [ 466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10 [ 466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000 [ 466.323057] [ 466.323064] Allocated by task 2605: [ 466.335165] save_stack+0x19/0x80 [ 466.336240] __kasan_kmalloc.constprop.8+0xa0/0xd0 [ 466.337755] kmem_cache_alloc+0xe8/0x320 [ 466.339050] getname_flags+0xca/0x560 [ 466.340229] user_path_at_empty+0x2c/0x50 [ 466.341508] vfs_statx+0xe6/0x190 [ 466.342619] __do_sys_newstat+0x81/0x100 [ 466.343908] do_syscall_64+0xc8/0x600 [ 466.345303] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.347034] [ 466.347517] Freed by task 2605: [ 466.348471] save_stack+0x19/0x80 [ 466.349476] __kasan_slab_free+0x12e/0x180 [ 466.350726] kmem_cache_free+0xc8/0x430 [ 466.351874] putname+0xe2/0x120 [ 466.352921] filename_lookup+0x257/0x3e0 [ 466.354319] vfs_statx+0xe6/0x190 [ 466.355498] __do_sys_newstat+0x81/0x100 [ 466.356889] do_syscall_64+0xc8/0x600 [ 466.358037] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.359567] [ 466.360050] The buggy address belongs to the object at ffff888372139100 [ 466.360050] which belongs to the cache names_cache of size 4096 [ 466.363735] The buggy address is located 336 bytes inside of [ 466.363735] 4096-byte region [ffff888372139100, ffff88837213a100) [ 466.367179] The buggy address belongs to the page: [ 466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0 [ 466.371582] flags: 0x2fffff80010200(slab|head) [ 466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00 [ 466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 [ 466.377778] page dumped because: kasan: bad access detected [ 466.379730] [ 466.380288] Memory state around the buggy address: [ 466.381844] ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.384009] ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.388257] ^ [ 466.390234] ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.392512] ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.394667] ================================================================== tun_chr_read_iter() accessed the memory which freed by free_netdev() called by tun_set_iff(): CPUA CPUB tun_set_iff() alloc_netdev_mqs() tun_attach() tun_chr_read_iter() tun_get() tun_do_read() tun_ring_recv() register_netdevice() <-- inject error goto err_detach tun_detach_all() <-- set RCV_SHUTDOWN free_netdev() <-- called from err_free_dev path netdev_freemem() <-- free the memory without check refcount (In this path, the refcount cannot prevent freeing the memory of dev, and the memory will be used by dev_put() called by tun_chr_read_iter() on CPUB.) (Break from tun_ring_recv(), because RCV_SHUTDOWN is set) tun_put() dev_put() <-- use the memory freed by netdev_freemem() Put the publishing of tfile->tun after register_netdevice(), so tun_get() won't get the tun pointer that freed by err_detach path if register_netdevice() failed. Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice") Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-10 10:56:57 +00:00
if (publish_tun)
rcu_assign_pointer(tfile->tun, tun);
rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
tun->numqueues++;
tun_set_real_num_queues(tun);
out:
return err;
}
static struct tun_struct *tun_get(struct tun_file *tfile)
{
struct tun_struct *tun;
rcu_read_lock();
tun = rcu_dereference(tfile->tun);
if (tun)
dev_hold(tun->dev);
rcu_read_unlock();
return tun;
}
static void tun_put(struct tun_struct *tun)
{
dev_put(tun->dev);
}
/* TAP filtering */
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
static void addr_hash_set(u32 *mask, const u8 *addr)
{
int n = ether_crc(ETH_ALEN, addr) >> 26;
mask[n >> 5] |= (1 << (n & 31));
}
static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
{
int n = ether_crc(ETH_ALEN, addr) >> 26;
return mask[n >> 5] & (1 << (n & 31));
}
static int update_filter(struct tap_filter *filter, void __user *arg)
{
struct { u8 u[ETH_ALEN]; } *addr;
struct tun_filter uf;
int err, alen, n, nexact;
if (copy_from_user(&uf, arg, sizeof(uf)))
return -EFAULT;
if (!uf.count) {
/* Disabled */
filter->count = 0;
return 0;
}
alen = ETH_ALEN * uf.count;
addr = memdup_user(arg + sizeof(uf), alen);
if (IS_ERR(addr))
return PTR_ERR(addr);
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
/* The filter is updated without holding any locks. Which is
* perfectly safe. We disable it first and in the worst
* case we'll accept a few undesired packets. */
filter->count = 0;
wmb();
/* Use first set of addresses as an exact filter */
for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
nexact = n;
/* Remaining multicast addresses are hashed,
* unicast will leave the filter disabled. */
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
memset(filter->mask, 0, sizeof(filter->mask));
for (; n < uf.count; n++) {
if (!is_multicast_ether_addr(addr[n].u)) {
err = 0; /* no filter */
goto free_addr;
}
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
addr_hash_set(filter->mask, addr[n].u);
}
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
/* For ALLMULTI just set the mask to all ones.
* This overrides the mask populated above. */
if ((uf.flags & TUN_FLT_ALLMULTI))
memset(filter->mask, ~0, sizeof(filter->mask));
/* Now enable the filter */
wmb();
filter->count = nexact;
/* Return the number of exact filters */
err = nexact;
free_addr:
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
kfree(addr);
return err;
}
/* Returns: 0 - drop, !=0 - accept */
static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
{
/* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
* at this point. */
struct ethhdr *eh = (struct ethhdr *) skb->data;
int i;
/* Exact match */
for (i = 0; i < filter->count; i++)
if (ether_addr_equal(eh->h_dest, filter->addr[i]))
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
return 1;
/* Inexact match (multicast only) */
if (is_multicast_ether_addr(eh->h_dest))
return addr_hash_test(filter->mask, eh->h_dest);
return 0;
}
/*
* Checks whether the packet is accepted or not.
* Returns: 0 - drop, !=0 - accept
*/
static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
{
if (!filter->count)
return 1;
return run_filter(filter, skb);
}
/* Network device part of the driver */
static const struct ethtool_ops tun_ethtool_ops;
/* Net device detach from fd. */
static void tun_net_uninit(struct net_device *dev)
{
tun_detach_all(dev);
}
/* Net device open. */
static int tun_net_open(struct net_device *dev)
{
netif_tx_start_all_queues(dev);
tun: fix premature POLLOUT notification on tun devices aszlig observed failing ssh tunnels (-w) during initialization since commit cc9da6cc4f56e0 ("ipv6: addrconf: use stable address generator for ARPHRD_NONE"). We already had reports that the mentioned commit breaks Juniper VPN connections. I can't clearly say that the Juniper VPN client has the same problem, but it is worth a try to hint to this patch. Because of the early generation of link local addresses, the kernel now can start asking for routers on the local subnet much earlier than usual. Those router solicitation packets arrive inside the ssh channels and should be transmitted to the tun fd before the configuration scripts might have upped the interface and made it ready for transmission. ssh polls on the interface and receives back a POLL_OUT. It tries to send the earily router solicitation packet to the tun interface. Unfortunately it hasn't been up'ed yet by config scripts, thus failing with -EIO. ssh doesn't retry again and considers the tun interface broken forever. Link: https://bugzilla.kernel.org/show_bug.cgi?id=121131 Fixes: cc9da6cc4f56 ("ipv6: addrconf: use stable address generator for ARPHRD_NONE") Cc: Bjørn Mork <bjorn@mork.no> Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Reported-by: Jonas Lippuner <jonas@lippuner.ca> Cc: Jonas Lippuner <jonas@lippuner.ca> Reported-by: aszlig <aszlig@redmoonstudios.org> Cc: aszlig <aszlig@redmoonstudios.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-12 23:00:26 +00:00
return 0;
}
/* Net device close. */
static int tun_net_close(struct net_device *dev)
{
netif_tx_stop_all_queues(dev);
return 0;
}
/* Net device start xmit */
static void tun_automq_xmit(struct tun_struct *tun, struct sk_buff *skb)
{
#ifdef CONFIG_RPS
if (tun->numqueues == 1 && static_branch_unlikely(&rps_needed)) {
/* Select queue was not called for the skbuff, so we extract the
* RPS hash and save it into the flow_table here.
*/
struct tun_flow_entry *e;
__u32 rxhash;
rxhash = __skb_get_hash_symmetric(skb);
e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)], rxhash);
if (e)
tun_flow_save_rps_rxhash(e, rxhash);
}
#endif
}
static unsigned int run_ebpf_filter(struct tun_struct *tun,
struct sk_buff *skb,
int len)
{
struct tun_prog *prog = rcu_dereference(tun->filter_prog);
if (prog)
len = bpf_prog_run_clear_cb(prog->prog, skb);
return len;
}
/* Net device start xmit */
static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
int txq = skb->queue_mapping;
struct tun_file *tfile;
int len = skb->len;
rcu_read_lock();
tfile = rcu_dereference(tun->tfiles[txq]);
/* Drop packet if interface is not attached */
if (!tfile)
goto drop;
if (!rcu_dereference(tun->steering_prog))
tun_automq_xmit(tun, skb);
netif_info(tun, tx_queued, tun->dev, "%s %d\n", __func__, skb->len);
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
/* Drop if the filter does not like it.
* This is a noop if the filter is disabled.
* Filter can be enabled only for the TAP devices. */
if (!check_filter(&tun->txflt, skb))
goto drop;
if (tfile->socket.sk->sk_filter &&
sk_filter(tfile->socket.sk, skb))
goto drop;
len = run_ebpf_filter(tun, skb, len);
tun: fix vlan packet truncation Bogus trimming in tun_net_xmit() causes truncated vlan packets. skb->len is correct whether or not skb_vlan_tag_present() is true. There is no more reason to adjust the skb length on xmit in this driver than any other driver. tun_put_user() adds 4 bytes to the total for tagged packets because it transmits the tag inline to userspace. This is similar to a nic transmitting the tag inline on the wire. Reproducing the bug by sending any tagged packet through back-to-back connected tap interfaces: socat TUN,tun-type=tap,iff-up,tun-name=in TUN,tun-type=tap,iff-up,tun-name=out & ip link add link in name in.20 type vlan id 20 ip addr add 10.9.9.9/24 dev in.20 ip link set in.20 up tshark -nxxi in -f arp -c1 2>/dev/null & tshark -nxxi out -f arp -c1 2>/dev/null & ping -c 1 10.9.9.5 >/dev/null 2>&1 The output from the 'in' and 'out' interfaces are different when the bug is present: Capturing on 'in' 0000 ff ff ff ff ff ff 76 cf 76 37 d5 0a 81 00 00 14 ......v.v7...... 0010 08 06 00 01 08 00 06 04 00 01 76 cf 76 37 d5 0a ..........v.v7.. 0020 0a 09 09 09 00 00 00 00 00 00 0a 09 09 05 .............. Capturing on 'out' 0000 ff ff ff ff ff ff 76 cf 76 37 d5 0a 81 00 00 14 ......v.v7...... 0010 08 06 00 01 08 00 06 04 00 01 76 cf 76 37 d5 0a ..........v.v7.. 0020 0a 09 09 09 00 00 00 00 00 00 .......... Fixes: aff3d70a07ff ("tun: allow to attach ebpf socket filter") Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Bjørn Mork <bjorn@mork.no> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 20:46:38 +00:00
if (len == 0 || pskb_trim(skb, len))
goto drop;
if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
goto drop;
skb_tx_timestamp(skb);
/* Orphan the skb - required as we might hang on to it
* for indefinite time.
*/
skb_orphan(skb);
nf_reset_ct(skb);
tun: add a missing nf_reset() in tun_net_xmit() Dave reported following crash : general protection fault: 0000 [#1] SMP CPU 2 Pid: 25407, comm: qemu-kvm Not tainted 3.7.9-205.fc18.x86_64 #1 Hewlett-Packard HP Z400 Workstation/0B4Ch RIP: 0010:[<ffffffffa0399bd5>] [<ffffffffa0399bd5>] destroy_conntrack+0x35/0x120 [nf_conntrack] RSP: 0018:ffff880276913d78 EFLAGS: 00010206 RAX: 50626b6b7876376c RBX: ffff88026e530d68 RCX: ffff88028d158e00 RDX: ffff88026d0d5470 RSI: 0000000000000011 RDI: 0000000000000002 RBP: ffff880276913d88 R08: 0000000000000000 R09: ffff880295002900 R10: 0000000000000000 R11: 0000000000000003 R12: ffffffff81ca3b40 R13: ffffffff8151a8e0 R14: ffff880270875000 R15: 0000000000000002 FS: 00007ff3bce38a00(0000) GS:ffff88029fc40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007fd1430bd000 CR3: 000000027042b000 CR4: 00000000000027e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process qemu-kvm (pid: 25407, threadinfo ffff880276912000, task ffff88028c369720) Stack: ffff880156f59100 ffff880156f59100 ffff880276913d98 ffffffff815534f7 ffff880276913db8 ffffffff8151a74b ffff880270875000 ffff880156f59100 ffff880276913dd8 ffffffff8151a5a6 ffff880276913dd8 ffff88026d0d5470 Call Trace: [<ffffffff815534f7>] nf_conntrack_destroy+0x17/0x20 [<ffffffff8151a74b>] skb_release_head_state+0x7b/0x100 [<ffffffff8151a5a6>] __kfree_skb+0x16/0xa0 [<ffffffff8151a666>] kfree_skb+0x36/0xa0 [<ffffffff8151a8e0>] skb_queue_purge+0x20/0x40 [<ffffffffa02205f7>] __tun_detach+0x117/0x140 [tun] [<ffffffffa022184c>] tun_chr_close+0x3c/0xd0 [tun] [<ffffffff8119669c>] __fput+0xec/0x240 [<ffffffff811967fe>] ____fput+0xe/0x10 [<ffffffff8107eb27>] task_work_run+0xa7/0xe0 [<ffffffff810149e1>] do_notify_resume+0x71/0xb0 [<ffffffff81640152>] int_signal+0x12/0x17 Code: 00 00 04 48 89 e5 41 54 53 48 89 fb 4c 8b a7 e8 00 00 00 0f 85 de 00 00 00 0f b6 73 3e 0f b7 7b 2a e8 10 40 00 00 48 85 c0 74 0e <48> 8b 40 28 48 85 c0 74 05 48 89 df ff d0 48 c7 c7 08 6a 3a a0 RIP [<ffffffffa0399bd5>] destroy_conntrack+0x35/0x120 [nf_conntrack] RSP <ffff880276913d78> This is because tun_net_xmit() needs to call nf_reset() before queuing skb into receive_queue Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-06 11:02:37 +00:00
if (ptr_ring_produce(&tfile->tx_ring, skb))
goto drop;
/* Notify and wake up reader process */
if (tfile->flags & TUN_FASYNC)
kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
tfile->socket.sk->sk_data_ready(tfile->socket.sk);
rcu_read_unlock();
return NETDEV_TX_OK;
drop:
atomic_long_inc(&dev->tx_dropped);
skb_tx_error(skb);
kfree_skb(skb);
rcu_read_unlock();
return NET_XMIT_DROP;
}
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
static void tun_net_mclist(struct net_device *dev)
{
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
/*
* This callback is supposed to deal with mc filter in
* _rx_ path and has nothing to do with the _tx_ path.
* In rx path we always accept everything userspace gives us.
*/
}
static netdev_features_t tun_net_fix_features(struct net_device *dev,
netdev_features_t features)
{
struct tun_struct *tun = netdev_priv(dev);
return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
}
static void tun_set_headroom(struct net_device *dev, int new_hr)
{
struct tun_struct *tun = netdev_priv(dev);
if (new_hr < NET_SKB_PAD)
new_hr = NET_SKB_PAD;
tun->align = new_hr;
}
static void
tun_net_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
{
struct tun_struct *tun = netdev_priv(dev);
dev_get_tstats64(dev, stats);
stats->rx_frame_errors +=
(unsigned long)atomic_long_read(&tun->rx_frame_errors);
}
static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
struct netlink_ext_ack *extack)
{
struct tun_struct *tun = netdev_priv(dev);
struct tun_file *tfile;
struct bpf_prog *old_prog;
int i;
old_prog = rtnl_dereference(tun->xdp_prog);
rcu_assign_pointer(tun->xdp_prog, prog);
if (old_prog)
bpf_prog_put(old_prog);
for (i = 0; i < tun->numqueues; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
if (prog)
sock_set_flag(&tfile->sk, SOCK_XDP);
else
sock_reset_flag(&tfile->sk, SOCK_XDP);
}
list_for_each_entry(tfile, &tun->disabled, next) {
if (prog)
sock_set_flag(&tfile->sk, SOCK_XDP);
else
sock_reset_flag(&tfile->sk, SOCK_XDP);
}
return 0;
}
static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
return tun_xdp_set(dev, xdp->prog, xdp->extack);
default:
return -EINVAL;
}
}
static int tun_net_change_carrier(struct net_device *dev, bool new_carrier)
{
if (new_carrier) {
struct tun_struct *tun = netdev_priv(dev);
if (!tun->numqueues)
return -EPERM;
netif_carrier_on(dev);
} else {
netif_carrier_off(dev);
}
return 0;
}
static const struct net_device_ops tun_netdev_ops = {
.ndo_uninit = tun_net_uninit,
.ndo_open = tun_net_open,
.ndo_stop = tun_net_close,
.ndo_start_xmit = tun_net_xmit,
.ndo_fix_features = tun_net_fix_features,
.ndo_select_queue = tun_select_queue,
.ndo_set_rx_headroom = tun_set_headroom,
.ndo_get_stats64 = tun_net_get_stats64,
.ndo_change_carrier = tun_net_change_carrier,
};
static void __tun_xdp_flush_tfile(struct tun_file *tfile)
{
/* Notify and wake up reader process */
if (tfile->flags & TUN_FASYNC)
kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
tfile->socket.sk->sk_data_ready(tfile->socket.sk);
}
static int tun_xdp_xmit(struct net_device *dev, int n,
struct xdp_frame **frames, u32 flags)
{
struct tun_struct *tun = netdev_priv(dev);
struct tun_file *tfile;
u32 numqueues;
int drops = 0;
int cnt = n;
int i;
if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
return -EINVAL;
rcu_read_lock();
resample:
numqueues = READ_ONCE(tun->numqueues);
if (!numqueues) {
rcu_read_unlock();
return -ENXIO; /* Caller will free/return all frames */
}
tfile = rcu_dereference(tun->tfiles[smp_processor_id() %
numqueues]);
if (unlikely(!tfile))
goto resample;
spin_lock(&tfile->tx_ring.producer_lock);
for (i = 0; i < n; i++) {
struct xdp_frame *xdp = frames[i];
/* Encode the XDP flag into lowest bit for consumer to differ
* XDP buffer from sk_buff.
*/
void *frame = tun_xdp_to_ptr(xdp);
if (__ptr_ring_produce(&tfile->tx_ring, frame)) {
atomic_long_inc(&dev->tx_dropped);
xdp_return_frame_rx_napi(xdp);
drops++;
}
}
spin_unlock(&tfile->tx_ring.producer_lock);
if (flags & XDP_XMIT_FLUSH)
__tun_xdp_flush_tfile(tfile);
rcu_read_unlock();
return cnt - drops;
}
static int tun_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
{
struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
if (unlikely(!frame))
return -EOVERFLOW;
return tun_xdp_xmit(dev, 1, &frame, XDP_XMIT_FLUSH);
}
static const struct net_device_ops tap_netdev_ops = {
.ndo_uninit = tun_net_uninit,
.ndo_open = tun_net_open,
.ndo_stop = tun_net_close,
.ndo_start_xmit = tun_net_xmit,
.ndo_fix_features = tun_net_fix_features,
.ndo_set_rx_mode = tun_net_mclist,
.ndo_set_mac_address = eth_mac_addr,
.ndo_validate_addr = eth_validate_addr,
.ndo_select_queue = tun_select_queue,
.ndo_features_check = passthru_features_check,
.ndo_set_rx_headroom = tun_set_headroom,
.ndo_get_stats64 = dev_get_tstats64,
.ndo_bpf = tun_xdp,
.ndo_xdp_xmit = tun_xdp_xmit,
.ndo_change_carrier = tun_net_change_carrier,
};
static void tun_flow_init(struct tun_struct *tun)
{
int i;
for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
INIT_HLIST_HEAD(&tun->flows[i]);
tun->ageing_time = TUN_FLOW_EXPIRE;
treewide: setup_timer() -> timer_setup() This converts all remaining cases of the old setup_timer() API into using timer_setup(), where the callback argument is the structure already holding the struct timer_list. These should have no behavioral changes, since they just change which pointer is passed into the callback with the same available pointers after conversion. It handles the following examples, in addition to some other variations. Casting from unsigned long: void my_callback(unsigned long data) { struct something *ptr = (struct something *)data; ... } ... setup_timer(&ptr->my_timer, my_callback, ptr); and forced object casts: void my_callback(struct something *ptr) { ... } ... setup_timer(&ptr->my_timer, my_callback, (unsigned long)ptr); become: void my_callback(struct timer_list *t) { struct something *ptr = from_timer(ptr, t, my_timer); ... } ... timer_setup(&ptr->my_timer, my_callback, 0); Direct function assignments: void my_callback(unsigned long data) { struct something *ptr = (struct something *)data; ... } ... ptr->my_timer.function = my_callback; have a temporary cast added, along with converting the args: void my_callback(struct timer_list *t) { struct something *ptr = from_timer(ptr, t, my_timer); ... } ... ptr->my_timer.function = (TIMER_FUNC_TYPE)my_callback; And finally, callbacks without a data assignment: void my_callback(unsigned long data) { ... } ... setup_timer(&ptr->my_timer, my_callback, 0); have their argument renamed to verify they're unused during conversion: void my_callback(struct timer_list *unused) { ... } ... timer_setup(&ptr->my_timer, my_callback, 0); The conversion is done with the following Coccinelle script: spatch --very-quiet --all-includes --include-headers \ -I ./arch/x86/include -I ./arch/x86/include/generated \ -I ./include -I ./arch/x86/include/uapi \ -I ./arch/x86/include/generated/uapi -I ./include/uapi \ -I ./include/generated/uapi --include ./include/linux/kconfig.h \ --dir . \ --cocci-file ~/src/data/timer_setup.cocci @fix_address_of@ expression e; @@ setup_timer( -&(e) +&e , ...) // Update any raw setup_timer() usages that have a NULL callback, but // would otherwise match change_timer_function_usage, since the latter // will update all function assignments done in the face of a NULL // function initialization in setup_timer(). @change_timer_function_usage_NULL@ expression _E; identifier _timer; type _cast_data; @@ ( -setup_timer(&_E->_timer, NULL, _E); +timer_setup(&_E->_timer, NULL, 0); | -setup_timer(&_E->_timer, NULL, (_cast_data)_E); +timer_setup(&_E->_timer, NULL, 0); | -setup_timer(&_E._timer, NULL, &_E); +timer_setup(&_E._timer, NULL, 0); | -setup_timer(&_E._timer, NULL, (_cast_data)&_E); +timer_setup(&_E._timer, NULL, 0); ) @change_timer_function_usage@ expression _E; identifier _timer; struct timer_list _stl; identifier _callback; type _cast_func, _cast_data; @@ ( -setup_timer(&_E->_timer, _callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, &_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, &_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)&_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)&_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E._timer, _callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, &_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, &_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)&_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)&_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | _E->_timer@_stl.function = _callback; | _E->_timer@_stl.function = &_callback; | _E->_timer@_stl.function = (_cast_func)_callback; | _E->_timer@_stl.function = (_cast_func)&_callback; | _E._timer@_stl.function = _callback; | _E._timer@_stl.function = &_callback; | _E._timer@_stl.function = (_cast_func)_callback; | _E._timer@_stl.function = (_cast_func)&_callback; ) // callback(unsigned long arg) @change_callback_handle_cast depends on change_timer_function_usage@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _origtype; identifier _origarg; type _handletype; identifier _handle; @@ void _callback( -_origtype _origarg +struct timer_list *t ) { ( ... when != _origarg _handletype *_handle = -(_handletype *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle = -(void *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle; ... when != _handle _handle = -(_handletype *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle; ... when != _handle _handle = -(void *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg ) } // callback(unsigned long arg) without existing variable @change_callback_handle_cast_no_arg depends on change_timer_function_usage && !change_callback_handle_cast@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _origtype; identifier _origarg; type _handletype; @@ void _callback( -_origtype _origarg +struct timer_list *t ) { + _handletype *_origarg = from_timer(_origarg, t, _timer); + ... when != _origarg - (_handletype *)_origarg + _origarg ... when != _origarg } // Avoid already converted callbacks. @match_callback_converted depends on change_timer_function_usage && !change_callback_handle_cast && !change_callback_handle_cast_no_arg@ identifier change_timer_function_usage._callback; identifier t; @@ void _callback(struct timer_list *t) { ... } // callback(struct something *handle) @change_callback_handle_arg depends on change_timer_function_usage && !match_callback_converted && !change_callback_handle_cast && !change_callback_handle_cast_no_arg@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _handletype; identifier _handle; @@ void _callback( -_handletype *_handle +struct timer_list *t ) { + _handletype *_handle = from_timer(_handle, t, _timer); ... } // If change_callback_handle_arg ran on an empty function, remove // the added handler. @unchange_callback_handle_arg depends on change_timer_function_usage && change_callback_handle_arg@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _handletype; identifier _handle; identifier t; @@ void _callback(struct timer_list *t) { - _handletype *_handle = from_timer(_handle, t, _timer); } // We only want to refactor the setup_timer() data argument if we've found // the matching callback. This undoes changes in change_timer_function_usage. @unchange_timer_function_usage depends on change_timer_function_usage && !change_callback_handle_cast && !change_callback_handle_cast_no_arg && !change_callback_handle_arg@ expression change_timer_function_usage._E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type change_timer_function_usage._cast_data; @@ ( -timer_setup(&_E->_timer, _callback, 0); +setup_timer(&_E->_timer, _callback, (_cast_data)_E); | -timer_setup(&_E._timer, _callback, 0); +setup_timer(&_E._timer, _callback, (_cast_data)&_E); ) // If we fixed a callback from a .function assignment, fix the // assignment cast now. @change_timer_function_assignment depends on change_timer_function_usage && (change_callback_handle_cast || change_callback_handle_cast_no_arg || change_callback_handle_arg)@ expression change_timer_function_usage._E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type _cast_func; typedef TIMER_FUNC_TYPE; @@ ( _E->_timer.function = -_callback +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -&_callback +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -(_cast_func)_callback; +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -(_cast_func)&_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -&_callback; +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -(_cast_func)_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -(_cast_func)&_callback +(TIMER_FUNC_TYPE)_callback ; ) // Sometimes timer functions are called directly. Replace matched args. @change_timer_function_calls depends on change_timer_function_usage && (change_callback_handle_cast || change_callback_handle_cast_no_arg || change_callback_handle_arg)@ expression _E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type _cast_data; @@ _callback( ( -(_cast_data)_E +&_E->_timer | -(_cast_data)&_E +&_E._timer | -_E +&_E->_timer ) ) // If a timer has been configured without a data argument, it can be // converted without regard to the callback argument, since it is unused. @match_timer_function_unused_data@ expression _E; identifier _timer; identifier _callback; @@ ( -setup_timer(&_E->_timer, _callback, 0); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, 0L); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, 0UL); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0L); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0UL); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_timer, _callback, 0); +timer_setup(&_timer, _callback, 0); | -setup_timer(&_timer, _callback, 0L); +timer_setup(&_timer, _callback, 0); | -setup_timer(&_timer, _callback, 0UL); +timer_setup(&_timer, _callback, 0); | -setup_timer(_timer, _callback, 0); +timer_setup(_timer, _callback, 0); | -setup_timer(_timer, _callback, 0L); +timer_setup(_timer, _callback, 0); | -setup_timer(_timer, _callback, 0UL); +timer_setup(_timer, _callback, 0); ) @change_callback_unused_data depends on match_timer_function_unused_data@ identifier match_timer_function_unused_data._callback; type _origtype; identifier _origarg; @@ void _callback( -_origtype _origarg +struct timer_list *unused ) { ... when != _origarg } Signed-off-by: Kees Cook <keescook@chromium.org>
2017-10-16 21:43:17 +00:00
timer_setup(&tun->flow_gc_timer, tun_flow_cleanup, 0);
mod_timer(&tun->flow_gc_timer,
round_jiffies_up(jiffies + tun->ageing_time));
}
static void tun_flow_uninit(struct tun_struct *tun)
{
del_timer_sync(&tun->flow_gc_timer);
tun_flow_flush(tun);
}
net: use core MTU range checking in core net infra geneve: - Merge __geneve_change_mtu back into geneve_change_mtu, set max_mtu - This one isn't quite as straight-forward as others, could use some closer inspection and testing macvlan: - set min/max_mtu tun: - set min/max_mtu, remove tun_net_change_mtu vxlan: - Merge __vxlan_change_mtu back into vxlan_change_mtu - Set max_mtu to IP_MAX_MTU and retain dynamic MTU range checks in change_mtu function - This one is also not as straight-forward and could use closer inspection and testing from vxlan folks bridge: - set max_mtu of IP_MAX_MTU and retain dynamic MTU range checks in change_mtu function openvswitch: - set min/max_mtu, remove internal_dev_change_mtu - note: max_mtu wasn't checked previously, it's been set to 65535, which is the largest possible size supported sch_teql: - set min/max_mtu (note: max_mtu previously unchecked, used max of 65535) macsec: - min_mtu = 0, max_mtu = 65535 macvlan: - min_mtu = 0, max_mtu = 65535 ntb_netdev: - min_mtu = 0, max_mtu = 65535 veth: - min_mtu = 68, max_mtu = 65535 8021q: - min_mtu = 0, max_mtu = 65535 CC: netdev@vger.kernel.org CC: Nicolas Dichtel <nicolas.dichtel@6wind.com> CC: Hannes Frederic Sowa <hannes@stressinduktion.org> CC: Tom Herbert <tom@herbertland.com> CC: Daniel Borkmann <daniel@iogearbox.net> CC: Alexander Duyck <alexander.h.duyck@intel.com> CC: Paolo Abeni <pabeni@redhat.com> CC: Jiri Benc <jbenc@redhat.com> CC: WANG Cong <xiyou.wangcong@gmail.com> CC: Roopa Prabhu <roopa@cumulusnetworks.com> CC: Pravin B Shelar <pshelar@ovn.org> CC: Sabrina Dubroca <sd@queasysnail.net> CC: Patrick McHardy <kaber@trash.net> CC: Stephen Hemminger <stephen@networkplumber.org> CC: Pravin Shelar <pshelar@nicira.com> CC: Maxim Krasnyansky <maxk@qti.qualcomm.com> Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-20 17:55:20 +00:00
#define MIN_MTU 68
#define MAX_MTU 65535
/* Initialize net device. */
static void tun_net_init(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
switch (tun->flags & TUN_TYPE_MASK) {
case IFF_TUN:
dev->netdev_ops = &tun_netdev_ops;
dev->header_ops = &ip_tunnel_header_ops;
/* Point-to-Point TUN Device */
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->mtu = 1500;
/* Zero header length */
dev->type = ARPHRD_NONE;
dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
break;
case IFF_TAP:
dev->netdev_ops = &tap_netdev_ops;
/* Ethernet TAP Device */
ether_setup(dev);
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
eth_hw_addr_random(dev);
break;
}
net: use core MTU range checking in core net infra geneve: - Merge __geneve_change_mtu back into geneve_change_mtu, set max_mtu - This one isn't quite as straight-forward as others, could use some closer inspection and testing macvlan: - set min/max_mtu tun: - set min/max_mtu, remove tun_net_change_mtu vxlan: - Merge __vxlan_change_mtu back into vxlan_change_mtu - Set max_mtu to IP_MAX_MTU and retain dynamic MTU range checks in change_mtu function - This one is also not as straight-forward and could use closer inspection and testing from vxlan folks bridge: - set max_mtu of IP_MAX_MTU and retain dynamic MTU range checks in change_mtu function openvswitch: - set min/max_mtu, remove internal_dev_change_mtu - note: max_mtu wasn't checked previously, it's been set to 65535, which is the largest possible size supported sch_teql: - set min/max_mtu (note: max_mtu previously unchecked, used max of 65535) macsec: - min_mtu = 0, max_mtu = 65535 macvlan: - min_mtu = 0, max_mtu = 65535 ntb_netdev: - min_mtu = 0, max_mtu = 65535 veth: - min_mtu = 68, max_mtu = 65535 8021q: - min_mtu = 0, max_mtu = 65535 CC: netdev@vger.kernel.org CC: Nicolas Dichtel <nicolas.dichtel@6wind.com> CC: Hannes Frederic Sowa <hannes@stressinduktion.org> CC: Tom Herbert <tom@herbertland.com> CC: Daniel Borkmann <daniel@iogearbox.net> CC: Alexander Duyck <alexander.h.duyck@intel.com> CC: Paolo Abeni <pabeni@redhat.com> CC: Jiri Benc <jbenc@redhat.com> CC: WANG Cong <xiyou.wangcong@gmail.com> CC: Roopa Prabhu <roopa@cumulusnetworks.com> CC: Pravin B Shelar <pshelar@ovn.org> CC: Sabrina Dubroca <sd@queasysnail.net> CC: Patrick McHardy <kaber@trash.net> CC: Stephen Hemminger <stephen@networkplumber.org> CC: Pravin Shelar <pshelar@nicira.com> CC: Maxim Krasnyansky <maxk@qti.qualcomm.com> Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-20 17:55:20 +00:00
dev->min_mtu = MIN_MTU;
dev->max_mtu = MAX_MTU - dev->hard_header_len;
}
static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file *tfile)
{
struct sock *sk = tfile->socket.sk;
return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
}
/* Character device part */
/* Poll */
static __poll_t tun_chr_poll(struct file *file, poll_table *wait)
{
struct tun_file *tfile = file->private_data;
struct tun_struct *tun = tun_get(tfile);
struct sock *sk;
__poll_t mask = 0;
if (!tun)
return EPOLLERR;
sk = tfile->socket.sk;
poll_wait(file, sk_sleep(sk), wait);
if (!ptr_ring_empty(&tfile->tx_ring))
mask |= EPOLLIN | EPOLLRDNORM;
/* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
* guarantee EPOLLOUT to be raised by either here or
* tun_sock_write_space(). Then process could get notification
* after it writes to a down device and meets -EIO.
*/
if (tun_sock_writeable(tun, tfile) ||
(!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
tun_sock_writeable(tun, tfile)))
mask |= EPOLLOUT | EPOLLWRNORM;
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
if (tun->dev->reg_state != NETREG_REGISTERED)
mask = EPOLLERR;
tun_put(tun);
return mask;
}
static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile,
size_t len,
const struct iov_iter *it)
{
struct sk_buff *skb;
size_t linear;
int err;
int i;
if (it->nr_segs > MAX_SKB_FRAGS + 1)
return ERR_PTR(-ENOMEM);
local_bh_disable();
skb = napi_get_frags(&tfile->napi);
local_bh_enable();
if (!skb)
return ERR_PTR(-ENOMEM);
linear = iov_iter_single_seg_count(it);
err = __skb_grow(skb, linear);
if (err)
goto free;
skb->len = len;
skb->data_len = len - linear;
skb->truesize += skb->data_len;
for (i = 1; i < it->nr_segs; i++) {
size_t fragsz = it->iov[i].iov_len;
struct page *page;
void *frag;
if (fragsz == 0 || fragsz > PAGE_SIZE) {
err = -EINVAL;
goto free;
}
frag = netdev_alloc_frag(fragsz);
if (!frag) {
err = -ENOMEM;
goto free;
}
page = virt_to_head_page(frag);
skb_fill_page_desc(skb, i - 1, page,
frag - page_address(page), fragsz);
}
return skb;
free:
/* frees skb and all frags allocated with napi_alloc_frag() */
napi_free_frags(&tfile->napi);
return ERR_PTR(err);
}
/* prepad is the amount to reserve at front. len is length after that.
* linear is a hint as to how much to copy (usually headers). */
static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
size_t prepad, size_t len,
size_t linear, int noblock)
{
struct sock *sk = tfile->socket.sk;
struct sk_buff *skb;
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
int err;
/* Under a page? Don't bother with paged skb. */
if (prepad + len < PAGE_SIZE || !linear)
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
linear = len;
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
&err, 0);
if (!skb)
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
return ERR_PTR(err);
skb_reserve(skb, prepad);
skb_put(skb, linear);
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
skb->data_len = len - linear;
skb->len += len - linear;
return skb;
}
static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile,
struct sk_buff *skb, int more)
{
struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
struct sk_buff_head process_queue;
u32 rx_batched = tun->rx_batched;
bool rcv = false;
if (!rx_batched || (!more && skb_queue_empty(queue))) {
local_bh_disable();
skb_record_rx_queue(skb, tfile->queue_index);
netif_receive_skb(skb);
local_bh_enable();
return;
}
spin_lock(&queue->lock);
if (!more || skb_queue_len(queue) == rx_batched) {
__skb_queue_head_init(&process_queue);
skb_queue_splice_tail_init(queue, &process_queue);
rcv = true;
} else {
__skb_queue_tail(queue, skb);
}
spin_unlock(&queue->lock);
if (rcv) {
struct sk_buff *nskb;
local_bh_disable();
while ((nskb = __skb_dequeue(&process_queue))) {
skb_record_rx_queue(nskb, tfile->queue_index);
netif_receive_skb(nskb);
}
skb_record_rx_queue(skb, tfile->queue_index);
netif_receive_skb(skb);
local_bh_enable();
}
}
static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
int len, int noblock, bool zerocopy)
{
if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
return false;
if (tfile->socket.sk->sk_sndbuf != INT_MAX)
return false;
if (!noblock)
return false;
if (zerocopy)
return false;
if (SKB_DATA_ALIGN(len + TUN_RX_PAD) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
return false;
return true;
}
static struct sk_buff *__tun_build_skb(struct tun_file *tfile,
struct page_frag *alloc_frag, char *buf,
int buflen, int len, int pad)
{
struct sk_buff *skb = build_skb(buf, buflen);
if (!skb)
return ERR_PTR(-ENOMEM);
skb_reserve(skb, pad);
skb_put(skb, len);
skb_set_owner_w(skb, tfile->socket.sk);
get_page(alloc_frag->page);
alloc_frag->offset += buflen;
return skb;
}
static int tun_xdp_act(struct tun_struct *tun, struct bpf_prog *xdp_prog,
struct xdp_buff *xdp, u32 act)
{
int err;
switch (act) {
case XDP_REDIRECT:
err = xdp_do_redirect(tun->dev, xdp, xdp_prog);
if (err)
return err;
break;
case XDP_TX:
err = tun_xdp_tx(tun->dev, xdp);
if (err < 0)
return err;
break;
case XDP_PASS:
break;
default:
bpf_warn_invalid_xdp_action(act);
fallthrough;
case XDP_ABORTED:
trace_xdp_exception(tun->dev, xdp_prog, act);
fallthrough;
case XDP_DROP:
atomic_long_inc(&tun->dev->rx_dropped);
break;
}
return act;
}
static struct sk_buff *tun_build_skb(struct tun_struct *tun,
struct tun_file *tfile,
struct iov_iter *from,
struct virtio_net_hdr *hdr,
int len, int *skb_xdp)
{
struct page_frag *alloc_frag = &current->task_frag;
struct bpf_prog *xdp_prog;
int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
char *buf;
size_t copied;
int pad = TUN_RX_PAD;
int err = 0;
rcu_read_lock();
xdp_prog = rcu_dereference(tun->xdp_prog);
if (xdp_prog)
pad += XDP_PACKET_HEADROOM;
buflen += SKB_DATA_ALIGN(len + pad);
rcu_read_unlock();
alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
return ERR_PTR(-ENOMEM);
buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
copied = copy_page_from_iter(alloc_frag->page,
alloc_frag->offset + pad,
len, from);
if (copied != len)
return ERR_PTR(-EFAULT);
/* There's a small window that XDP may be set after the check
* of xdp_prog above, this should be rare and for simplicity
* we do XDP on skb in case the headroom is not enough.
*/
if (hdr->gso_type || !xdp_prog) {
*skb_xdp = 1;
return __tun_build_skb(tfile, alloc_frag, buf, buflen, len,
pad);
}
*skb_xdp = 0;
tun: Fix NULL pointer dereference in XDP redirect Calling XDP redirection requires bh disabled. Softirq can call another XDP function and redirection functions, then the percpu static variable ri->map can be overwritten to NULL. This is a generic XDP case called from tun. [ 3535.736058] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 3535.743974] PGD 0 P4D 0 [ 3535.746530] Oops: 0000 [#1] SMP PTI [ 3535.750049] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ipmi_ssif irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel crypto_simd cryptd enclosure hpwdt hpilo glue_helper ipmi_si pcspkr wmi mei_me ioatdma mei ipmi_devintf shpchp dca ipmi_msghandler lpc_ich acpi_power_meter sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm smartpqi i40e crc32c_intel scsi_transport_sas tg3 i2c_core ptp pps_core [ 3535.813456] CPU: 5 PID: 1630 Comm: vhost-1614 Not tainted 4.17.0-rc4 #2 [ 3535.820127] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 3535.828732] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 3535.833740] RSP: 0018:ffffb4bc47bf7c58 EFLAGS: 00010246 [ 3535.839009] RAX: ffff9fdfcfea1c40 RBX: 0000000000000000 RCX: ffff9fdf27fe3100 [ 3535.846205] RDX: ffff9fdfca769200 RSI: 0000000000000000 RDI: 0000000000000000 [ 3535.853402] RBP: ffffb4bc491d9000 R08: 00000000000045ad R09: 0000000000000ec0 [ 3535.860597] R10: 0000000000000001 R11: ffff9fdf26c3ce4e R12: ffff9fdf9e72c000 [ 3535.867794] R13: 0000000000000000 R14: fffffffffffffff2 R15: ffff9fdfc82cdd00 [ 3535.874990] FS: 0000000000000000(0000) GS:ffff9fdfcfe80000(0000) knlGS:0000000000000000 [ 3535.883152] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3535.888948] CR2: 0000000000000018 CR3: 0000000bde724004 CR4: 00000000007626e0 [ 3535.896145] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3535.903342] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 3535.910538] PKRU: 55555554 [ 3535.913267] Call Trace: [ 3535.915736] xdp_do_generic_redirect+0x7a/0x310 [ 3535.920310] do_xdp_generic.part.117+0x285/0x370 [ 3535.924970] tun_get_user+0x5b9/0x1260 [tun] [ 3535.929279] tun_sendmsg+0x52/0x70 [tun] [ 3535.933237] handle_tx+0x2ad/0x5f0 [vhost_net] [ 3535.937721] vhost_worker+0xa5/0x100 [vhost] [ 3535.942030] kthread+0xf5/0x130 [ 3535.945198] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 3535.950031] ? kthread_bind+0x10/0x10 [ 3535.953727] ret_from_fork+0x35/0x40 [ 3535.957334] Code: 0e 74 15 83 f8 10 75 05 e9 49 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 29 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 49 a9 b3 ff 31 c0 c3 [ 3535.976387] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffffb4bc47bf7c58 [ 3535.982883] CR2: 0000000000000018 [ 3535.987096] ---[ end trace 383b299dd1430240 ]--- [ 3536.131325] Kernel panic - not syncing: Fatal exception [ 3536.137484] Kernel Offset: 0x26a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 3536.281406] ---[ end Kernel panic - not syncing: Fatal exception ]--- And a kernel with generic case fixed still panics in tun driver XDP redirect, because it disabled only preemption, but not bh. [ 2055.128746] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 2055.136662] PGD 0 P4D 0 [ 2055.139219] Oops: 0000 [#1] SMP PTI [ 2055.142736] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel ipmi_ssif crypto_simd enclosure cryptd hpwdt glue_helper ioatdma hpilo wmi dca pcspkr ipmi_si acpi_power_meter ipmi_devintf shpchp mei_me ipmi_msghandler mei lpc_ich sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm i40e smartpqi tg3 scsi_transport_sas crc32c_intel i2c_core ptp pps_core [ 2055.206142] CPU: 6 PID: 1693 Comm: vhost-1683 Tainted: G W 4.17.0-rc5-fix-tun+ #1 [ 2055.215011] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 2055.223617] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 2055.228624] RSP: 0018:ffff998b07607cc0 EFLAGS: 00010246 [ 2055.233892] RAX: ffff8dbd8e235700 RBX: ffff8dbd8ff21c40 RCX: 0000000000000004 [ 2055.241089] RDX: ffff998b097a9000 RSI: 0000000000000000 RDI: 0000000000000000 [ 2055.248286] RBP: 0000000000000000 R08: 00000000000065a8 R09: 0000000000005d80 [ 2055.255483] R10: 0000000000000040 R11: ffff8dbcf0100000 R12: ffff998b097a9000 [ 2055.262681] R13: ffff8dbd8c98c000 R14: 0000000000000000 R15: ffff998b07607d78 [ 2055.269879] FS: 0000000000000000(0000) GS:ffff8dbd8ff00000(0000) knlGS:0000000000000000 [ 2055.278039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2055.283834] CR2: 0000000000000018 CR3: 0000000c0c8cc005 CR4: 00000000007626e0 [ 2055.291030] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2055.298227] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2055.305424] PKRU: 55555554 [ 2055.308153] Call Trace: [ 2055.310624] xdp_do_redirect+0x7b/0x380 [ 2055.314499] tun_get_user+0x10fe/0x12a0 [tun] [ 2055.318895] tun_sendmsg+0x52/0x70 [tun] [ 2055.322852] handle_tx+0x2ad/0x5f0 [vhost_net] [ 2055.327337] vhost_worker+0xa5/0x100 [vhost] [ 2055.331646] kthread+0xf5/0x130 [ 2055.334813] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 2055.339646] ? kthread_bind+0x10/0x10 [ 2055.343343] ret_from_fork+0x35/0x40 [ 2055.346950] Code: 0e 74 15 83 f8 10 75 05 e9 e9 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 c9 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 e9 a9 b3 ff 31 c0 c3 [ 2055.366004] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffff998b07607cc0 [ 2055.372500] CR2: 0000000000000018 [ 2055.375856] ---[ end trace 2a2dcc5e9e174268 ]--- [ 2055.523626] Kernel panic - not syncing: Fatal exception [ 2055.529796] Kernel Offset: 0x2e000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 2055.677539] ---[ end Kernel panic - not syncing: Fatal exception ]--- v2: - Removed preempt_disable/enable since local_bh_disable will prevent preemption as well, feedback from Jason Wang. Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-28 10:37:49 +00:00
local_bh_disable();
rcu_read_lock();
xdp_prog = rcu_dereference(tun->xdp_prog);
if (xdp_prog) {
struct xdp_buff xdp;
u32 act;
xdp.data_hard_start = buf;
xdp.data = buf + pad;
bpf: add meta pointer for direct access This work enables generic transfer of metadata from XDP into skb. The basic idea is that we can make use of the fact that the resulting skb must be linear and already comes with a larger headroom for supporting bpf_xdp_adjust_head(), which mangles xdp->data. Here, we base our work on a similar principle and introduce a small helper bpf_xdp_adjust_meta() for adjusting a new pointer called xdp->data_meta. Thus, the packet has a flexible and programmable room for meta data, followed by the actual packet data. struct xdp_buff is therefore laid out that we first point to data_hard_start, then data_meta directly prepended to data followed by data_end marking the end of packet. bpf_xdp_adjust_head() takes into account whether we have meta data already prepended and if so, memmove()s this along with the given offset provided there's enough room. xdp->data_meta is optional and programs are not required to use it. The rationale is that when we process the packet in XDP (e.g. as DoS filter), we can push further meta data along with it for the XDP_PASS case, and give the guarantee that a clsact ingress BPF program on the same device can pick this up for further post-processing. Since we work with skb there, we can also set skb->mark, skb->priority or other skb meta data out of BPF, thus having this scratch space generic and programmable allows for more flexibility than defining a direct 1:1 transfer of potentially new XDP members into skb (it's also more efficient as we don't need to initialize/handle each of such new members). The facility also works together with GRO aggregation. The scratch space at the head of the packet can be multiple of 4 byte up to 32 byte large. Drivers not yet supporting xdp->data_meta can simply be set up with xdp->data_meta as xdp->data + 1 as bpf_xdp_adjust_meta() will detect this and bail out, such that the subsequent match against xdp->data for later access is guaranteed to fail. The verifier treats xdp->data_meta/xdp->data the same way as we treat xdp->data/xdp->data_end pointer comparisons. The requirement for doing the compare against xdp->data is that it hasn't been modified from it's original address we got from ctx access. It may have a range marking already from prior successful xdp->data/xdp->data_end pointer comparisons though. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-25 00:25:51 +00:00
xdp_set_data_meta_invalid(&xdp);
xdp.data_end = xdp.data + len;
xdp.rxq = &tfile->xdp_rxq;
xdp.frame_sz = buflen;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
if (act == XDP_REDIRECT || act == XDP_TX) {
get_page(alloc_frag->page);
alloc_frag->offset += buflen;
}
err = tun_xdp_act(tun, xdp_prog, &xdp, act);
if (err < 0) {
if (act == XDP_REDIRECT || act == XDP_TX)
put_page(alloc_frag->page);
goto out;
}
if (err == XDP_REDIRECT)
xdp: Use bulking for non-map XDP_REDIRECT and consolidate code paths Since the bulk queue used by XDP_REDIRECT now lives in struct net_device, we can re-use the bulking for the non-map version of the bpf_redirect() helper. This is a simple matter of having xdp_do_redirect_slow() queue the frame on the bulk queue instead of sending it out with __bpf_tx_xdp(). Unfortunately we can't make the bpf_redirect() helper return an error if the ifindex doesn't exit (as bpf_redirect_map() does), because we don't have a reference to the network namespace of the ingress device at the time the helper is called. So we have to leave it as-is and keep the device lookup in xdp_do_redirect_slow(). Since this leaves less reason to have the non-map redirect code in a separate function, so we get rid of the xdp_do_redirect_slow() function entirely. This does lose us the tracepoint disambiguation, but fortunately the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint entry structures. This means both can contain a map index, so we can just amend the tracepoint definitions so we always emit the xdp_redirect(_err) tracepoints, but with the map ID only populated if a map is present. This means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep the definitions around in case someone is still listening for them. With this change, the performance of the xdp_redirect sample program goes from 5Mpps to 8.4Mpps (a 68% increase). Since the flush functions are no longer map-specific, rename the flush() functions to drop _map from their names. One of the renamed functions is the xdp_do_flush_map() callback used in all the xdp-enabled drivers. To keep from having to update all drivers, use a #define to keep the old name working, and only update the virtual drivers in this patch. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/157918768505.1458396.17518057312953572912.stgit@toke.dk
2020-01-16 15:14:45 +00:00
xdp_do_flush();
if (err != XDP_PASS)
goto out;
pad = xdp.data - xdp.data_hard_start;
len = xdp.data_end - xdp.data;
}
rcu_read_unlock();
local_bh_enable();
return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, pad);
out:
rcu_read_unlock();
tun: Fix NULL pointer dereference in XDP redirect Calling XDP redirection requires bh disabled. Softirq can call another XDP function and redirection functions, then the percpu static variable ri->map can be overwritten to NULL. This is a generic XDP case called from tun. [ 3535.736058] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 3535.743974] PGD 0 P4D 0 [ 3535.746530] Oops: 0000 [#1] SMP PTI [ 3535.750049] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ipmi_ssif irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel crypto_simd cryptd enclosure hpwdt hpilo glue_helper ipmi_si pcspkr wmi mei_me ioatdma mei ipmi_devintf shpchp dca ipmi_msghandler lpc_ich acpi_power_meter sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm smartpqi i40e crc32c_intel scsi_transport_sas tg3 i2c_core ptp pps_core [ 3535.813456] CPU: 5 PID: 1630 Comm: vhost-1614 Not tainted 4.17.0-rc4 #2 [ 3535.820127] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 3535.828732] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 3535.833740] RSP: 0018:ffffb4bc47bf7c58 EFLAGS: 00010246 [ 3535.839009] RAX: ffff9fdfcfea1c40 RBX: 0000000000000000 RCX: ffff9fdf27fe3100 [ 3535.846205] RDX: ffff9fdfca769200 RSI: 0000000000000000 RDI: 0000000000000000 [ 3535.853402] RBP: ffffb4bc491d9000 R08: 00000000000045ad R09: 0000000000000ec0 [ 3535.860597] R10: 0000000000000001 R11: ffff9fdf26c3ce4e R12: ffff9fdf9e72c000 [ 3535.867794] R13: 0000000000000000 R14: fffffffffffffff2 R15: ffff9fdfc82cdd00 [ 3535.874990] FS: 0000000000000000(0000) GS:ffff9fdfcfe80000(0000) knlGS:0000000000000000 [ 3535.883152] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3535.888948] CR2: 0000000000000018 CR3: 0000000bde724004 CR4: 00000000007626e0 [ 3535.896145] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3535.903342] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 3535.910538] PKRU: 55555554 [ 3535.913267] Call Trace: [ 3535.915736] xdp_do_generic_redirect+0x7a/0x310 [ 3535.920310] do_xdp_generic.part.117+0x285/0x370 [ 3535.924970] tun_get_user+0x5b9/0x1260 [tun] [ 3535.929279] tun_sendmsg+0x52/0x70 [tun] [ 3535.933237] handle_tx+0x2ad/0x5f0 [vhost_net] [ 3535.937721] vhost_worker+0xa5/0x100 [vhost] [ 3535.942030] kthread+0xf5/0x130 [ 3535.945198] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 3535.950031] ? kthread_bind+0x10/0x10 [ 3535.953727] ret_from_fork+0x35/0x40 [ 3535.957334] Code: 0e 74 15 83 f8 10 75 05 e9 49 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 29 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 49 a9 b3 ff 31 c0 c3 [ 3535.976387] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffffb4bc47bf7c58 [ 3535.982883] CR2: 0000000000000018 [ 3535.987096] ---[ end trace 383b299dd1430240 ]--- [ 3536.131325] Kernel panic - not syncing: Fatal exception [ 3536.137484] Kernel Offset: 0x26a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 3536.281406] ---[ end Kernel panic - not syncing: Fatal exception ]--- And a kernel with generic case fixed still panics in tun driver XDP redirect, because it disabled only preemption, but not bh. [ 2055.128746] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 2055.136662] PGD 0 P4D 0 [ 2055.139219] Oops: 0000 [#1] SMP PTI [ 2055.142736] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel ipmi_ssif crypto_simd enclosure cryptd hpwdt glue_helper ioatdma hpilo wmi dca pcspkr ipmi_si acpi_power_meter ipmi_devintf shpchp mei_me ipmi_msghandler mei lpc_ich sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm i40e smartpqi tg3 scsi_transport_sas crc32c_intel i2c_core ptp pps_core [ 2055.206142] CPU: 6 PID: 1693 Comm: vhost-1683 Tainted: G W 4.17.0-rc5-fix-tun+ #1 [ 2055.215011] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 2055.223617] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 2055.228624] RSP: 0018:ffff998b07607cc0 EFLAGS: 00010246 [ 2055.233892] RAX: ffff8dbd8e235700 RBX: ffff8dbd8ff21c40 RCX: 0000000000000004 [ 2055.241089] RDX: ffff998b097a9000 RSI: 0000000000000000 RDI: 0000000000000000 [ 2055.248286] RBP: 0000000000000000 R08: 00000000000065a8 R09: 0000000000005d80 [ 2055.255483] R10: 0000000000000040 R11: ffff8dbcf0100000 R12: ffff998b097a9000 [ 2055.262681] R13: ffff8dbd8c98c000 R14: 0000000000000000 R15: ffff998b07607d78 [ 2055.269879] FS: 0000000000000000(0000) GS:ffff8dbd8ff00000(0000) knlGS:0000000000000000 [ 2055.278039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2055.283834] CR2: 0000000000000018 CR3: 0000000c0c8cc005 CR4: 00000000007626e0 [ 2055.291030] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2055.298227] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2055.305424] PKRU: 55555554 [ 2055.308153] Call Trace: [ 2055.310624] xdp_do_redirect+0x7b/0x380 [ 2055.314499] tun_get_user+0x10fe/0x12a0 [tun] [ 2055.318895] tun_sendmsg+0x52/0x70 [tun] [ 2055.322852] handle_tx+0x2ad/0x5f0 [vhost_net] [ 2055.327337] vhost_worker+0xa5/0x100 [vhost] [ 2055.331646] kthread+0xf5/0x130 [ 2055.334813] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 2055.339646] ? kthread_bind+0x10/0x10 [ 2055.343343] ret_from_fork+0x35/0x40 [ 2055.346950] Code: 0e 74 15 83 f8 10 75 05 e9 e9 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 c9 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 e9 a9 b3 ff 31 c0 c3 [ 2055.366004] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffff998b07607cc0 [ 2055.372500] CR2: 0000000000000018 [ 2055.375856] ---[ end trace 2a2dcc5e9e174268 ]--- [ 2055.523626] Kernel panic - not syncing: Fatal exception [ 2055.529796] Kernel Offset: 0x2e000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 2055.677539] ---[ end Kernel panic - not syncing: Fatal exception ]--- v2: - Removed preempt_disable/enable since local_bh_disable will prevent preemption as well, feedback from Jason Wang. Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-28 10:37:49 +00:00
local_bh_enable();
return NULL;
}
/* Get packet from user space buffer */
static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
void *msg_control, struct iov_iter *from,
int noblock, bool more)
{
struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
struct sk_buff *skb;
size_t total_len = iov_iter_count(from);
size_t len = total_len, align = tun->align, linear;
struct virtio_net_hdr gso = { 0 };
int good_linear;
int copylen;
bool zerocopy = false;
int err;
u32 rxhash = 0;
int skb_xdp = 1;
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
bool frags = tun_napi_frags_enabled(tfile);
if (!(tun->flags & IFF_NO_PI)) {
if (len < sizeof(pi))
return -EINVAL;
len -= sizeof(pi);
if (!copy_from_iter_full(&pi, sizeof(pi), from))
return -EFAULT;
}
if (tun->flags & IFF_VNET_HDR) {
int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
if (len < vnet_hdr_sz)
return -EINVAL;
len -= vnet_hdr_sz;
if (!copy_from_iter_full(&gso, sizeof(gso), from))
return -EFAULT;
if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
if (tun16_to_cpu(tun, gso.hdr_len) > len)
return -EINVAL;
iov_iter_advance(from, vnet_hdr_sz - sizeof(gso));
}
if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
align += NET_IP_ALIGN;
if (unlikely(len < ETH_HLEN ||
(gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
return -EINVAL;
}
good_linear = SKB_MAX_HEAD(align);
if (msg_control) {
struct iov_iter i = *from;
/* There are 256 bytes to be copied in skb, so there is
* enough room for skb expand head in case it is used.
* The rest of the buffer is mapped from userspace.
*/
copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
if (copylen > good_linear)
copylen = good_linear;
linear = copylen;
iov_iter_advance(&i, copylen);
if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
zerocopy = true;
}
if (!frags && tun_can_build_skb(tun, tfile, len, noblock, zerocopy)) {
/* For the packet that is not easy to be processed
* (e.g gso or jumbo packet), we will do it at after
* skb was created with generic XDP routine.
*/
skb = tun_build_skb(tun, tfile, from, &gso, len, &skb_xdp);
if (IS_ERR(skb)) {
atomic_long_inc(&tun->dev->rx_dropped);
return PTR_ERR(skb);
}
if (!skb)
return total_len;
} else {
if (!zerocopy) {
copylen = len;
if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
linear = good_linear;
else
linear = tun16_to_cpu(tun, gso.hdr_len);
}
if (frags) {
mutex_lock(&tfile->napi_mutex);
skb = tun_napi_alloc_frags(tfile, copylen, from);
/* tun_napi_alloc_frags() enforces a layout for the skb.
* If zerocopy is enabled, then this layout will be
* overwritten by zerocopy_sg_from_iter().
*/
zerocopy = false;
} else {
skb = tun_alloc_skb(tfile, align, copylen, linear,
noblock);
}
if (IS_ERR(skb)) {
if (PTR_ERR(skb) != -EAGAIN)
atomic_long_inc(&tun->dev->rx_dropped);
if (frags)
mutex_unlock(&tfile->napi_mutex);
return PTR_ERR(skb);
}
if (zerocopy)
err = zerocopy_sg_from_iter(skb, from);
else
err = skb_copy_datagram_from_iter(skb, 0, from, len);
if (err) {
err = -EFAULT;
drop:
atomic_long_inc(&tun->dev->rx_dropped);
kfree_skb(skb);
if (frags) {
tfile->napi.skb = NULL;
mutex_unlock(&tfile->napi_mutex);
}
return err;
}
}
if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) {
atomic_long_inc(&tun->rx_frame_errors);
kfree_skb(skb);
if (frags) {
tfile->napi.skb = NULL;
mutex_unlock(&tfile->napi_mutex);
}
return -EINVAL;
}
switch (tun->flags & TUN_TYPE_MASK) {
case IFF_TUN:
if (tun->flags & IFF_NO_PI) {
tun: bail out from tun_get_user() if the skb is empty KMSAN (https://github.com/google/kmsan) reported accessing uninitialized skb->data[0] in the case the skb is empty (i.e. skb->len is 0): ================================================ BUG: KMSAN: use of uninitialized memory in tun_get_user+0x19ba/0x3770 CPU: 0 PID: 3051 Comm: probe Not tainted 4.13.0+ #3140 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: ... __msan_warning_32+0x66/0xb0 mm/kmsan/kmsan_instr.c:477 tun_get_user+0x19ba/0x3770 drivers/net/tun.c:1301 tun_chr_write_iter+0x19f/0x300 drivers/net/tun.c:1365 call_write_iter ./include/linux/fs.h:1743 new_sync_write fs/read_write.c:457 __vfs_write+0x6c3/0x7f0 fs/read_write.c:470 vfs_write+0x3e4/0x770 fs/read_write.c:518 SYSC_write+0x12f/0x2b0 fs/read_write.c:565 SyS_write+0x55/0x80 fs/read_write.c:557 do_syscall_64+0x242/0x330 arch/x86/entry/common.c:284 entry_SYSCALL64_slow_path+0x25/0x25 arch/x86/entry/entry_64.S:245 ... origin: ... kmsan_poison_shadow+0x6e/0xc0 mm/kmsan/kmsan.c:211 slab_alloc_node mm/slub.c:2732 __kmalloc_node_track_caller+0x351/0x370 mm/slub.c:4351 __kmalloc_reserve net/core/skbuff.c:138 __alloc_skb+0x26a/0x810 net/core/skbuff.c:231 alloc_skb ./include/linux/skbuff.h:903 alloc_skb_with_frags+0x1d7/0xc80 net/core/skbuff.c:4756 sock_alloc_send_pskb+0xabf/0xfe0 net/core/sock.c:2037 tun_alloc_skb drivers/net/tun.c:1144 tun_get_user+0x9a8/0x3770 drivers/net/tun.c:1274 tun_chr_write_iter+0x19f/0x300 drivers/net/tun.c:1365 call_write_iter ./include/linux/fs.h:1743 new_sync_write fs/read_write.c:457 __vfs_write+0x6c3/0x7f0 fs/read_write.c:470 vfs_write+0x3e4/0x770 fs/read_write.c:518 SYSC_write+0x12f/0x2b0 fs/read_write.c:565 SyS_write+0x55/0x80 fs/read_write.c:557 do_syscall_64+0x242/0x330 arch/x86/entry/common.c:284 return_from_SYSCALL_64+0x0/0x6a arch/x86/entry/entry_64.S:245 ================================================ Make sure tun_get_user() doesn't touch skb->data[0] unless there is actual data. C reproducer below: ========================== // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include <fcntl.h> #include <linux/if_tun.h> #include <netinet/ip.h> #include <net/if.h> #include <string.h> #include <sys/ioctl.h> int main() { int sock = socket(PF_INET, SOCK_STREAM, IPPROTO_IP); int tun_fd = open("/dev/net/tun", O_RDWR); struct ifreq req; memset(&req, 0, sizeof(struct ifreq)); strcpy((char*)&req.ifr_name, "gre0"); req.ifr_flags = IFF_UP | IFF_MULTICAST; ioctl(tun_fd, TUNSETIFF, &req); ioctl(sock, SIOCSIFFLAGS, "gre0"); write(tun_fd, "hi", 0); return 0; } ========================== Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-28 09:32:37 +00:00
u8 ip_version = skb->len ? (skb->data[0] >> 4) : 0;
switch (ip_version) {
case 4:
pi.proto = htons(ETH_P_IP);
break;
tun: bail out from tun_get_user() if the skb is empty KMSAN (https://github.com/google/kmsan) reported accessing uninitialized skb->data[0] in the case the skb is empty (i.e. skb->len is 0): ================================================ BUG: KMSAN: use of uninitialized memory in tun_get_user+0x19ba/0x3770 CPU: 0 PID: 3051 Comm: probe Not tainted 4.13.0+ #3140 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: ... __msan_warning_32+0x66/0xb0 mm/kmsan/kmsan_instr.c:477 tun_get_user+0x19ba/0x3770 drivers/net/tun.c:1301 tun_chr_write_iter+0x19f/0x300 drivers/net/tun.c:1365 call_write_iter ./include/linux/fs.h:1743 new_sync_write fs/read_write.c:457 __vfs_write+0x6c3/0x7f0 fs/read_write.c:470 vfs_write+0x3e4/0x770 fs/read_write.c:518 SYSC_write+0x12f/0x2b0 fs/read_write.c:565 SyS_write+0x55/0x80 fs/read_write.c:557 do_syscall_64+0x242/0x330 arch/x86/entry/common.c:284 entry_SYSCALL64_slow_path+0x25/0x25 arch/x86/entry/entry_64.S:245 ... origin: ... kmsan_poison_shadow+0x6e/0xc0 mm/kmsan/kmsan.c:211 slab_alloc_node mm/slub.c:2732 __kmalloc_node_track_caller+0x351/0x370 mm/slub.c:4351 __kmalloc_reserve net/core/skbuff.c:138 __alloc_skb+0x26a/0x810 net/core/skbuff.c:231 alloc_skb ./include/linux/skbuff.h:903 alloc_skb_with_frags+0x1d7/0xc80 net/core/skbuff.c:4756 sock_alloc_send_pskb+0xabf/0xfe0 net/core/sock.c:2037 tun_alloc_skb drivers/net/tun.c:1144 tun_get_user+0x9a8/0x3770 drivers/net/tun.c:1274 tun_chr_write_iter+0x19f/0x300 drivers/net/tun.c:1365 call_write_iter ./include/linux/fs.h:1743 new_sync_write fs/read_write.c:457 __vfs_write+0x6c3/0x7f0 fs/read_write.c:470 vfs_write+0x3e4/0x770 fs/read_write.c:518 SYSC_write+0x12f/0x2b0 fs/read_write.c:565 SyS_write+0x55/0x80 fs/read_write.c:557 do_syscall_64+0x242/0x330 arch/x86/entry/common.c:284 return_from_SYSCALL_64+0x0/0x6a arch/x86/entry/entry_64.S:245 ================================================ Make sure tun_get_user() doesn't touch skb->data[0] unless there is actual data. C reproducer below: ========================== // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include <fcntl.h> #include <linux/if_tun.h> #include <netinet/ip.h> #include <net/if.h> #include <string.h> #include <sys/ioctl.h> int main() { int sock = socket(PF_INET, SOCK_STREAM, IPPROTO_IP); int tun_fd = open("/dev/net/tun", O_RDWR); struct ifreq req; memset(&req, 0, sizeof(struct ifreq)); strcpy((char*)&req.ifr_name, "gre0"); req.ifr_flags = IFF_UP | IFF_MULTICAST; ioctl(tun_fd, TUNSETIFF, &req); ioctl(sock, SIOCSIFFLAGS, "gre0"); write(tun_fd, "hi", 0); return 0; } ========================== Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-28 09:32:37 +00:00
case 6:
pi.proto = htons(ETH_P_IPV6);
break;
default:
atomic_long_inc(&tun->dev->rx_dropped);
kfree_skb(skb);
return -EINVAL;
}
}
skb_reset_mac_header(skb);
skb->protocol = pi.proto;
skb->dev = tun->dev;
break;
case IFF_TAP:
if (frags && !pskb_may_pull(skb, ETH_HLEN)) {
err = -ENOMEM;
goto drop;
}
skb->protocol = eth_type_trans(skb, tun->dev);
break;
}
/* copy skb_ubuf_info for callback when skb has no error */
if (zerocopy) {
skb_shinfo(skb)->destructor_arg = msg_control;
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
} else if (msg_control) {
struct ubuf_info *uarg = msg_control;
uarg->callback(uarg, false);
}
skb_reset_network_header(skb);
skb_probe_transport_header(skb);
skb_record_rx_queue(skb, tfile->queue_index);
if (skb_xdp) {
struct bpf_prog *xdp_prog;
int ret;
tun: Fix NULL pointer dereference in XDP redirect Calling XDP redirection requires bh disabled. Softirq can call another XDP function and redirection functions, then the percpu static variable ri->map can be overwritten to NULL. This is a generic XDP case called from tun. [ 3535.736058] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 3535.743974] PGD 0 P4D 0 [ 3535.746530] Oops: 0000 [#1] SMP PTI [ 3535.750049] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ipmi_ssif irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel crypto_simd cryptd enclosure hpwdt hpilo glue_helper ipmi_si pcspkr wmi mei_me ioatdma mei ipmi_devintf shpchp dca ipmi_msghandler lpc_ich acpi_power_meter sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm smartpqi i40e crc32c_intel scsi_transport_sas tg3 i2c_core ptp pps_core [ 3535.813456] CPU: 5 PID: 1630 Comm: vhost-1614 Not tainted 4.17.0-rc4 #2 [ 3535.820127] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 3535.828732] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 3535.833740] RSP: 0018:ffffb4bc47bf7c58 EFLAGS: 00010246 [ 3535.839009] RAX: ffff9fdfcfea1c40 RBX: 0000000000000000 RCX: ffff9fdf27fe3100 [ 3535.846205] RDX: ffff9fdfca769200 RSI: 0000000000000000 RDI: 0000000000000000 [ 3535.853402] RBP: ffffb4bc491d9000 R08: 00000000000045ad R09: 0000000000000ec0 [ 3535.860597] R10: 0000000000000001 R11: ffff9fdf26c3ce4e R12: ffff9fdf9e72c000 [ 3535.867794] R13: 0000000000000000 R14: fffffffffffffff2 R15: ffff9fdfc82cdd00 [ 3535.874990] FS: 0000000000000000(0000) GS:ffff9fdfcfe80000(0000) knlGS:0000000000000000 [ 3535.883152] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3535.888948] CR2: 0000000000000018 CR3: 0000000bde724004 CR4: 00000000007626e0 [ 3535.896145] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3535.903342] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 3535.910538] PKRU: 55555554 [ 3535.913267] Call Trace: [ 3535.915736] xdp_do_generic_redirect+0x7a/0x310 [ 3535.920310] do_xdp_generic.part.117+0x285/0x370 [ 3535.924970] tun_get_user+0x5b9/0x1260 [tun] [ 3535.929279] tun_sendmsg+0x52/0x70 [tun] [ 3535.933237] handle_tx+0x2ad/0x5f0 [vhost_net] [ 3535.937721] vhost_worker+0xa5/0x100 [vhost] [ 3535.942030] kthread+0xf5/0x130 [ 3535.945198] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 3535.950031] ? kthread_bind+0x10/0x10 [ 3535.953727] ret_from_fork+0x35/0x40 [ 3535.957334] Code: 0e 74 15 83 f8 10 75 05 e9 49 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 29 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 49 a9 b3 ff 31 c0 c3 [ 3535.976387] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffffb4bc47bf7c58 [ 3535.982883] CR2: 0000000000000018 [ 3535.987096] ---[ end trace 383b299dd1430240 ]--- [ 3536.131325] Kernel panic - not syncing: Fatal exception [ 3536.137484] Kernel Offset: 0x26a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 3536.281406] ---[ end Kernel panic - not syncing: Fatal exception ]--- And a kernel with generic case fixed still panics in tun driver XDP redirect, because it disabled only preemption, but not bh. [ 2055.128746] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 2055.136662] PGD 0 P4D 0 [ 2055.139219] Oops: 0000 [#1] SMP PTI [ 2055.142736] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel ipmi_ssif crypto_simd enclosure cryptd hpwdt glue_helper ioatdma hpilo wmi dca pcspkr ipmi_si acpi_power_meter ipmi_devintf shpchp mei_me ipmi_msghandler mei lpc_ich sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm i40e smartpqi tg3 scsi_transport_sas crc32c_intel i2c_core ptp pps_core [ 2055.206142] CPU: 6 PID: 1693 Comm: vhost-1683 Tainted: G W 4.17.0-rc5-fix-tun+ #1 [ 2055.215011] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 2055.223617] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 2055.228624] RSP: 0018:ffff998b07607cc0 EFLAGS: 00010246 [ 2055.233892] RAX: ffff8dbd8e235700 RBX: ffff8dbd8ff21c40 RCX: 0000000000000004 [ 2055.241089] RDX: ffff998b097a9000 RSI: 0000000000000000 RDI: 0000000000000000 [ 2055.248286] RBP: 0000000000000000 R08: 00000000000065a8 R09: 0000000000005d80 [ 2055.255483] R10: 0000000000000040 R11: ffff8dbcf0100000 R12: ffff998b097a9000 [ 2055.262681] R13: ffff8dbd8c98c000 R14: 0000000000000000 R15: ffff998b07607d78 [ 2055.269879] FS: 0000000000000000(0000) GS:ffff8dbd8ff00000(0000) knlGS:0000000000000000 [ 2055.278039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2055.283834] CR2: 0000000000000018 CR3: 0000000c0c8cc005 CR4: 00000000007626e0 [ 2055.291030] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2055.298227] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2055.305424] PKRU: 55555554 [ 2055.308153] Call Trace: [ 2055.310624] xdp_do_redirect+0x7b/0x380 [ 2055.314499] tun_get_user+0x10fe/0x12a0 [tun] [ 2055.318895] tun_sendmsg+0x52/0x70 [tun] [ 2055.322852] handle_tx+0x2ad/0x5f0 [vhost_net] [ 2055.327337] vhost_worker+0xa5/0x100 [vhost] [ 2055.331646] kthread+0xf5/0x130 [ 2055.334813] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 2055.339646] ? kthread_bind+0x10/0x10 [ 2055.343343] ret_from_fork+0x35/0x40 [ 2055.346950] Code: 0e 74 15 83 f8 10 75 05 e9 e9 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 c9 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 e9 a9 b3 ff 31 c0 c3 [ 2055.366004] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffff998b07607cc0 [ 2055.372500] CR2: 0000000000000018 [ 2055.375856] ---[ end trace 2a2dcc5e9e174268 ]--- [ 2055.523626] Kernel panic - not syncing: Fatal exception [ 2055.529796] Kernel Offset: 0x2e000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 2055.677539] ---[ end Kernel panic - not syncing: Fatal exception ]--- v2: - Removed preempt_disable/enable since local_bh_disable will prevent preemption as well, feedback from Jason Wang. Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-28 10:37:49 +00:00
local_bh_disable();
rcu_read_lock();
xdp_prog = rcu_dereference(tun->xdp_prog);
if (xdp_prog) {
ret = do_xdp_generic(xdp_prog, skb);
if (ret != XDP_PASS) {
rcu_read_unlock();
tun: Fix NULL pointer dereference in XDP redirect Calling XDP redirection requires bh disabled. Softirq can call another XDP function and redirection functions, then the percpu static variable ri->map can be overwritten to NULL. This is a generic XDP case called from tun. [ 3535.736058] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 3535.743974] PGD 0 P4D 0 [ 3535.746530] Oops: 0000 [#1] SMP PTI [ 3535.750049] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ipmi_ssif irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel crypto_simd cryptd enclosure hpwdt hpilo glue_helper ipmi_si pcspkr wmi mei_me ioatdma mei ipmi_devintf shpchp dca ipmi_msghandler lpc_ich acpi_power_meter sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm smartpqi i40e crc32c_intel scsi_transport_sas tg3 i2c_core ptp pps_core [ 3535.813456] CPU: 5 PID: 1630 Comm: vhost-1614 Not tainted 4.17.0-rc4 #2 [ 3535.820127] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 3535.828732] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 3535.833740] RSP: 0018:ffffb4bc47bf7c58 EFLAGS: 00010246 [ 3535.839009] RAX: ffff9fdfcfea1c40 RBX: 0000000000000000 RCX: ffff9fdf27fe3100 [ 3535.846205] RDX: ffff9fdfca769200 RSI: 0000000000000000 RDI: 0000000000000000 [ 3535.853402] RBP: ffffb4bc491d9000 R08: 00000000000045ad R09: 0000000000000ec0 [ 3535.860597] R10: 0000000000000001 R11: ffff9fdf26c3ce4e R12: ffff9fdf9e72c000 [ 3535.867794] R13: 0000000000000000 R14: fffffffffffffff2 R15: ffff9fdfc82cdd00 [ 3535.874990] FS: 0000000000000000(0000) GS:ffff9fdfcfe80000(0000) knlGS:0000000000000000 [ 3535.883152] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3535.888948] CR2: 0000000000000018 CR3: 0000000bde724004 CR4: 00000000007626e0 [ 3535.896145] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3535.903342] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 3535.910538] PKRU: 55555554 [ 3535.913267] Call Trace: [ 3535.915736] xdp_do_generic_redirect+0x7a/0x310 [ 3535.920310] do_xdp_generic.part.117+0x285/0x370 [ 3535.924970] tun_get_user+0x5b9/0x1260 [tun] [ 3535.929279] tun_sendmsg+0x52/0x70 [tun] [ 3535.933237] handle_tx+0x2ad/0x5f0 [vhost_net] [ 3535.937721] vhost_worker+0xa5/0x100 [vhost] [ 3535.942030] kthread+0xf5/0x130 [ 3535.945198] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 3535.950031] ? kthread_bind+0x10/0x10 [ 3535.953727] ret_from_fork+0x35/0x40 [ 3535.957334] Code: 0e 74 15 83 f8 10 75 05 e9 49 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 29 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 49 a9 b3 ff 31 c0 c3 [ 3535.976387] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffffb4bc47bf7c58 [ 3535.982883] CR2: 0000000000000018 [ 3535.987096] ---[ end trace 383b299dd1430240 ]--- [ 3536.131325] Kernel panic - not syncing: Fatal exception [ 3536.137484] Kernel Offset: 0x26a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 3536.281406] ---[ end Kernel panic - not syncing: Fatal exception ]--- And a kernel with generic case fixed still panics in tun driver XDP redirect, because it disabled only preemption, but not bh. [ 2055.128746] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 2055.136662] PGD 0 P4D 0 [ 2055.139219] Oops: 0000 [#1] SMP PTI [ 2055.142736] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel ipmi_ssif crypto_simd enclosure cryptd hpwdt glue_helper ioatdma hpilo wmi dca pcspkr ipmi_si acpi_power_meter ipmi_devintf shpchp mei_me ipmi_msghandler mei lpc_ich sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm i40e smartpqi tg3 scsi_transport_sas crc32c_intel i2c_core ptp pps_core [ 2055.206142] CPU: 6 PID: 1693 Comm: vhost-1683 Tainted: G W 4.17.0-rc5-fix-tun+ #1 [ 2055.215011] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 2055.223617] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 2055.228624] RSP: 0018:ffff998b07607cc0 EFLAGS: 00010246 [ 2055.233892] RAX: ffff8dbd8e235700 RBX: ffff8dbd8ff21c40 RCX: 0000000000000004 [ 2055.241089] RDX: ffff998b097a9000 RSI: 0000000000000000 RDI: 0000000000000000 [ 2055.248286] RBP: 0000000000000000 R08: 00000000000065a8 R09: 0000000000005d80 [ 2055.255483] R10: 0000000000000040 R11: ffff8dbcf0100000 R12: ffff998b097a9000 [ 2055.262681] R13: ffff8dbd8c98c000 R14: 0000000000000000 R15: ffff998b07607d78 [ 2055.269879] FS: 0000000000000000(0000) GS:ffff8dbd8ff00000(0000) knlGS:0000000000000000 [ 2055.278039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2055.283834] CR2: 0000000000000018 CR3: 0000000c0c8cc005 CR4: 00000000007626e0 [ 2055.291030] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2055.298227] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2055.305424] PKRU: 55555554 [ 2055.308153] Call Trace: [ 2055.310624] xdp_do_redirect+0x7b/0x380 [ 2055.314499] tun_get_user+0x10fe/0x12a0 [tun] [ 2055.318895] tun_sendmsg+0x52/0x70 [tun] [ 2055.322852] handle_tx+0x2ad/0x5f0 [vhost_net] [ 2055.327337] vhost_worker+0xa5/0x100 [vhost] [ 2055.331646] kthread+0xf5/0x130 [ 2055.334813] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 2055.339646] ? kthread_bind+0x10/0x10 [ 2055.343343] ret_from_fork+0x35/0x40 [ 2055.346950] Code: 0e 74 15 83 f8 10 75 05 e9 e9 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 c9 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 e9 a9 b3 ff 31 c0 c3 [ 2055.366004] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffff998b07607cc0 [ 2055.372500] CR2: 0000000000000018 [ 2055.375856] ---[ end trace 2a2dcc5e9e174268 ]--- [ 2055.523626] Kernel panic - not syncing: Fatal exception [ 2055.529796] Kernel Offset: 0x2e000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 2055.677539] ---[ end Kernel panic - not syncing: Fatal exception ]--- v2: - Removed preempt_disable/enable since local_bh_disable will prevent preemption as well, feedback from Jason Wang. Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-28 10:37:49 +00:00
local_bh_enable();
if (frags) {
tfile->napi.skb = NULL;
mutex_unlock(&tfile->napi_mutex);
}
return total_len;
}
}
rcu_read_unlock();
tun: Fix NULL pointer dereference in XDP redirect Calling XDP redirection requires bh disabled. Softirq can call another XDP function and redirection functions, then the percpu static variable ri->map can be overwritten to NULL. This is a generic XDP case called from tun. [ 3535.736058] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 3535.743974] PGD 0 P4D 0 [ 3535.746530] Oops: 0000 [#1] SMP PTI [ 3535.750049] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ipmi_ssif irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel crypto_simd cryptd enclosure hpwdt hpilo glue_helper ipmi_si pcspkr wmi mei_me ioatdma mei ipmi_devintf shpchp dca ipmi_msghandler lpc_ich acpi_power_meter sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm smartpqi i40e crc32c_intel scsi_transport_sas tg3 i2c_core ptp pps_core [ 3535.813456] CPU: 5 PID: 1630 Comm: vhost-1614 Not tainted 4.17.0-rc4 #2 [ 3535.820127] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 3535.828732] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 3535.833740] RSP: 0018:ffffb4bc47bf7c58 EFLAGS: 00010246 [ 3535.839009] RAX: ffff9fdfcfea1c40 RBX: 0000000000000000 RCX: ffff9fdf27fe3100 [ 3535.846205] RDX: ffff9fdfca769200 RSI: 0000000000000000 RDI: 0000000000000000 [ 3535.853402] RBP: ffffb4bc491d9000 R08: 00000000000045ad R09: 0000000000000ec0 [ 3535.860597] R10: 0000000000000001 R11: ffff9fdf26c3ce4e R12: ffff9fdf9e72c000 [ 3535.867794] R13: 0000000000000000 R14: fffffffffffffff2 R15: ffff9fdfc82cdd00 [ 3535.874990] FS: 0000000000000000(0000) GS:ffff9fdfcfe80000(0000) knlGS:0000000000000000 [ 3535.883152] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3535.888948] CR2: 0000000000000018 CR3: 0000000bde724004 CR4: 00000000007626e0 [ 3535.896145] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3535.903342] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 3535.910538] PKRU: 55555554 [ 3535.913267] Call Trace: [ 3535.915736] xdp_do_generic_redirect+0x7a/0x310 [ 3535.920310] do_xdp_generic.part.117+0x285/0x370 [ 3535.924970] tun_get_user+0x5b9/0x1260 [tun] [ 3535.929279] tun_sendmsg+0x52/0x70 [tun] [ 3535.933237] handle_tx+0x2ad/0x5f0 [vhost_net] [ 3535.937721] vhost_worker+0xa5/0x100 [vhost] [ 3535.942030] kthread+0xf5/0x130 [ 3535.945198] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 3535.950031] ? kthread_bind+0x10/0x10 [ 3535.953727] ret_from_fork+0x35/0x40 [ 3535.957334] Code: 0e 74 15 83 f8 10 75 05 e9 49 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 29 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 49 a9 b3 ff 31 c0 c3 [ 3535.976387] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffffb4bc47bf7c58 [ 3535.982883] CR2: 0000000000000018 [ 3535.987096] ---[ end trace 383b299dd1430240 ]--- [ 3536.131325] Kernel panic - not syncing: Fatal exception [ 3536.137484] Kernel Offset: 0x26a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 3536.281406] ---[ end Kernel panic - not syncing: Fatal exception ]--- And a kernel with generic case fixed still panics in tun driver XDP redirect, because it disabled only preemption, but not bh. [ 2055.128746] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 2055.136662] PGD 0 P4D 0 [ 2055.139219] Oops: 0000 [#1] SMP PTI [ 2055.142736] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel ipmi_ssif crypto_simd enclosure cryptd hpwdt glue_helper ioatdma hpilo wmi dca pcspkr ipmi_si acpi_power_meter ipmi_devintf shpchp mei_me ipmi_msghandler mei lpc_ich sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm i40e smartpqi tg3 scsi_transport_sas crc32c_intel i2c_core ptp pps_core [ 2055.206142] CPU: 6 PID: 1693 Comm: vhost-1683 Tainted: G W 4.17.0-rc5-fix-tun+ #1 [ 2055.215011] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 2055.223617] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 2055.228624] RSP: 0018:ffff998b07607cc0 EFLAGS: 00010246 [ 2055.233892] RAX: ffff8dbd8e235700 RBX: ffff8dbd8ff21c40 RCX: 0000000000000004 [ 2055.241089] RDX: ffff998b097a9000 RSI: 0000000000000000 RDI: 0000000000000000 [ 2055.248286] RBP: 0000000000000000 R08: 00000000000065a8 R09: 0000000000005d80 [ 2055.255483] R10: 0000000000000040 R11: ffff8dbcf0100000 R12: ffff998b097a9000 [ 2055.262681] R13: ffff8dbd8c98c000 R14: 0000000000000000 R15: ffff998b07607d78 [ 2055.269879] FS: 0000000000000000(0000) GS:ffff8dbd8ff00000(0000) knlGS:0000000000000000 [ 2055.278039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2055.283834] CR2: 0000000000000018 CR3: 0000000c0c8cc005 CR4: 00000000007626e0 [ 2055.291030] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2055.298227] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2055.305424] PKRU: 55555554 [ 2055.308153] Call Trace: [ 2055.310624] xdp_do_redirect+0x7b/0x380 [ 2055.314499] tun_get_user+0x10fe/0x12a0 [tun] [ 2055.318895] tun_sendmsg+0x52/0x70 [tun] [ 2055.322852] handle_tx+0x2ad/0x5f0 [vhost_net] [ 2055.327337] vhost_worker+0xa5/0x100 [vhost] [ 2055.331646] kthread+0xf5/0x130 [ 2055.334813] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 2055.339646] ? kthread_bind+0x10/0x10 [ 2055.343343] ret_from_fork+0x35/0x40 [ 2055.346950] Code: 0e 74 15 83 f8 10 75 05 e9 e9 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 c9 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 e9 a9 b3 ff 31 c0 c3 [ 2055.366004] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffff998b07607cc0 [ 2055.372500] CR2: 0000000000000018 [ 2055.375856] ---[ end trace 2a2dcc5e9e174268 ]--- [ 2055.523626] Kernel panic - not syncing: Fatal exception [ 2055.529796] Kernel Offset: 0x2e000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 2055.677539] ---[ end Kernel panic - not syncing: Fatal exception ]--- v2: - Removed preempt_disable/enable since local_bh_disable will prevent preemption as well, feedback from Jason Wang. Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-28 10:37:49 +00:00
local_bh_enable();
}
/* Compute the costly rx hash only if needed for flow updates.
* We may get a very small possibility of OOO during switching, not
* worth to optimize.
*/
if (!rcu_access_pointer(tun->steering_prog) && tun->numqueues > 1 &&
!tfile->detached)
rxhash = __skb_get_hash_symmetric(skb);
rcu_read_lock();
if (unlikely(!(tun->dev->flags & IFF_UP))) {
err = -EIO;
rcu_read_unlock();
goto drop;
}
if (frags) {
u32 headlen;
/* Exercise flow dissector code path. */
skb_push(skb, ETH_HLEN);
headlen = eth_get_headlen(tun->dev, skb->data,
skb_headlen(skb));
if (unlikely(headlen > skb_headlen(skb))) {
atomic_long_inc(&tun->dev->rx_dropped);
napi_free_frags(&tfile->napi);
rcu_read_unlock();
mutex_unlock(&tfile->napi_mutex);
WARN_ON(1);
return -ENOMEM;
}
local_bh_disable();
napi_gro_frags(&tfile->napi);
local_bh_enable();
mutex_unlock(&tfile->napi_mutex);
net-tun: fix panics at dismantle time syzkaller got crashes at dismantle time [1] It is not correct to test (tun->flags & IFF_NAPI) in tun_napi_disable() and tun_napi_del() : Each tun_file can have different mode, depending on how they were created. Similarly I have changed tun_get_user() and tun_poll_controller() to use the new tfile->napi_enabled boolean. [ 154.331360] BUG: unable to handle kernel NULL pointer dereference at (null) [ 154.339220] IP: [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.344983] PGD 0 [ 154.347009] Oops: 0000 [#1] SMP [ 154.350680] gsmi: Log Shutdown Reason 0x03 [ 154.379572] task: ffff994719150dc0 ti: ffff99475c0ae000 task.ti: ffff99475c0ae000 [ 154.387043] RIP: 0010:[<ffffffff9634cad6>] [<ffffffff9634cad6>] hrtimer_active+0x26/0x60 [ 154.395232] RSP: 0018:ffff99475c0afce8 EFLAGS: 00010246 [ 154.400542] RAX: ffff994754850ac0 RBX: ffff994753e65408 RCX: ffff994753e65388 [ 154.407666] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff994753e65408 [ 154.414790] RBP: ffff99475c0afce8 R08: 0000000000000000 R09: 0000000000000000 [ 154.421921] R10: ffff99475f6f5910 R11: 0000000000000001 R12: 0000000000000000 [ 154.429044] R13: ffff99417deab668 R14: ffff99417deaa780 R15: ffff99475f45dde0 [ 154.436174] FS: 0000000000000000(0000) GS:ffff994767a00000(0000) knlGS:0000000000000000 [ 154.444249] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 154.449986] CR2: 0000000000000000 CR3: 00000005a8a0e000 CR4: 0000000000022670 [ 154.457110] Stack: [ 154.459120] ffff99475c0afd28 ffffffff9634d614 1000000000000000 0000000000000000 [ 154.466598] ffffe54240000000 ffff994753e65408 ffff994753e653a8 ffff99417deab668 [ 154.474067] ffff99475c0afd48 ffffffff9634d6fd ffff99474c2be678 ffff994753e65398 [ 154.481537] Call Trace: [ 154.483985] [<ffffffff9634d614>] hrtimer_try_to_cancel+0x24/0xf0 [ 154.490074] [<ffffffff9634d6fd>] hrtimer_cancel+0x1d/0x30 [ 154.495563] [<ffffffff96860b3c>] napi_disable+0x3c/0x70 [ 154.500875] [<ffffffff9678ae62>] __tun_detach+0xd2/0x360 [ 154.506272] [<ffffffff9678b117>] tun_chr_close+0x27/0x40 [ 154.511669] [<ffffffff9646ebe6>] __fput+0xd6/0x1e0 [ 154.516548] [<ffffffff9646ed3e>] ____fput+0xe/0x10 [ 154.521429] [<ffffffff963035a2>] task_work_run+0x72/0x90 [ 154.526827] [<ffffffff962e9407>] do_exit+0x317/0xb60 [ 154.531879] [<ffffffff962e9c8f>] do_group_exit+0x3f/0xa0 [ 154.537275] [<ffffffff962e9d07>] SyS_exit_group+0x17/0x20 [ 154.542769] [<ffffffff969784be>] entry_SYSCALL_64_fastpath+0x12/0x17 Fixes: 943170998b20 ("net-tun: enable NAPI for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18 19:12:09 +00:00
} else if (tfile->napi_enabled) {
struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
int queue_len;
spin_lock_bh(&queue->lock);
__skb_queue_tail(queue, skb);
queue_len = skb_queue_len(queue);
spin_unlock(&queue->lock);
if (!more || queue_len > NAPI_POLL_WEIGHT)
napi_schedule(&tfile->napi);
local_bh_enable();
} else if (!IS_ENABLED(CONFIG_4KSTACKS)) {
tun_rx_batched(tun, tfile, skb, more);
} else {
netif_rx_ni(skb);
}
rcu_read_unlock();
preempt_disable();
dev_sw_netstats_rx_add(tun->dev, len);
preempt_enable();
if (rxhash)
tun_flow_update(tun, rxhash, tfile);
return total_len;
}
static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
struct file *file = iocb->ki_filp;
struct tun_file *tfile = file->private_data;
struct tun_struct *tun = tun_get(tfile);
ssize_t result;
if (!tun)
return -EBADFD;
result = tun_get_user(tun, tfile, NULL, from,
file->f_flags & O_NONBLOCK, false);
tun_put(tun);
return result;
}
static ssize_t tun_put_user_xdp(struct tun_struct *tun,
struct tun_file *tfile,
struct xdp_frame *xdp_frame,
struct iov_iter *iter)
{
int vnet_hdr_sz = 0;
size_t size = xdp_frame->len;
size_t ret;
if (tun->flags & IFF_VNET_HDR) {
struct virtio_net_hdr gso = { 0 };
vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
if (unlikely(iov_iter_count(iter) < vnet_hdr_sz))
return -EINVAL;
if (unlikely(copy_to_iter(&gso, sizeof(gso), iter) !=
sizeof(gso)))
return -EFAULT;
iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
}
ret = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz;
preempt_disable();
dev_sw_netstats_tx_add(tun->dev, 1, ret);
preempt_enable();
return ret;
}
/* Put packet to the user space buffer */
static ssize_t tun_put_user(struct tun_struct *tun,
struct tun_file *tfile,
struct sk_buff *skb,
struct iov_iter *iter)
{
struct tun_pi pi = { 0, skb->protocol };
ssize_t total;
int vlan_offset = 0;
int vlan_hlen = 0;
int vnet_hdr_sz = 0;
if (skb_vlan_tag_present(skb))
vlan_hlen = VLAN_HLEN;
if (tun->flags & IFF_VNET_HDR)
vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
total = skb->len + vlan_hlen + vnet_hdr_sz;
if (!(tun->flags & IFF_NO_PI)) {
if (iov_iter_count(iter) < sizeof(pi))
return -EINVAL;
total += sizeof(pi);
if (iov_iter_count(iter) < total) {
/* Packet will be striped */
pi.flags |= TUN_PKT_STRIP;
}
if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
return -EFAULT;
}
if (vnet_hdr_sz) {
struct virtio_net_hdr gso;
if (iov_iter_count(iter) < vnet_hdr_sz)
return -EINVAL;
if (virtio_net_hdr_from_skb(skb, &gso,
tun_is_little_endian(tun), true,
vlan_hlen)) {
struct skb_shared_info *sinfo = skb_shinfo(skb);
pr_err("unexpected GSO type: "
"0x%x, gso_size %d, hdr_len %d\n",
sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
tun16_to_cpu(tun, gso.hdr_len));
print_hex_dump(KERN_ERR, "tun: ",
DUMP_PREFIX_NONE,
16, 1, skb->head,
min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
WARN_ON_ONCE(1);
return -EINVAL;
}
if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
return -EFAULT;
iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
}
if (vlan_hlen) {
int ret;
struct veth veth;
veth.h_vlan_proto = skb->vlan_proto;
veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
if (ret || !iov_iter_count(iter))
goto done;
ret = copy_to_iter(&veth, sizeof(veth), iter);
if (ret != sizeof(veth) || !iov_iter_count(iter))
goto done;
}
skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
done:
/* caller is in process context, */
preempt_disable();
dev_sw_netstats_tx_add(tun->dev, 1, skb->len + vlan_hlen);
preempt_enable();
return total;
}
static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
{
DECLARE_WAITQUEUE(wait, current);
void *ptr = NULL;
int error = 0;
ptr = ptr_ring_consume(&tfile->tx_ring);
if (ptr)
goto out;
if (noblock) {
error = -EAGAIN;
goto out;
}
add_wait_queue(&tfile->socket.wq.wait, &wait);
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
ptr = ptr_ring_consume(&tfile->tx_ring);
if (ptr)
break;
if (signal_pending(current)) {
error = -ERESTARTSYS;
break;
}
if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
error = -EFAULT;
break;
}
schedule();
}
__set_current_state(TASK_RUNNING);
remove_wait_queue(&tfile->socket.wq.wait, &wait);
out:
*err = error;
return ptr;
}
static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
struct iov_iter *to,
int noblock, void *ptr)
{
ssize_t ret;
int err;
if (!iov_iter_count(to)) {
tun_ptr_free(ptr);
return 0;
}
if (!ptr) {
/* Read frames from ring */
ptr = tun_ring_recv(tfile, noblock, &err);
if (!ptr)
return err;
}
if (tun_is_xdp_frame(ptr)) {
struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
ret = tun_put_user_xdp(tun, tfile, xdpf, to);
xdp: transition into using xdp_frame for return API Changing API xdp_return_frame() to take struct xdp_frame as argument, seems like a natural choice. But there are some subtle performance details here that needs extra care, which is a deliberate choice. When de-referencing xdp_frame on a remote CPU during DMA-TX completion, result in the cache-line is change to "Shared" state. Later when the page is reused for RX, then this xdp_frame cache-line is written, which change the state to "Modified". This situation already happens (naturally) for, virtio_net, tun and cpumap as the xdp_frame pointer is the queued object. In tun and cpumap, the ptr_ring is used for efficiently transferring cache-lines (with pointers) between CPUs. Thus, the only option is to de-referencing xdp_frame. It is only the ixgbe driver that had an optimization, in which it can avoid doing the de-reference of xdp_frame. The driver already have TX-ring queue, which (in case of remote DMA-TX completion) have to be transferred between CPUs anyhow. In this data area, we stored a struct xdp_mem_info and a data pointer, which allowed us to avoid de-referencing xdp_frame. To compensate for this, a prefetchw is used for telling the cache coherency protocol about our access pattern. My benchmarks show that this prefetchw is enough to compensate the ixgbe driver. V7: Adjust for commit d9314c474d4f ("i40e: add support for XDP_REDIRECT") V8: Adjust for commit bd658dda4237 ("net/mlx5e: Separate dma base address and offset in dma_sync call") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 14:46:32 +00:00
xdp_return_frame(xdpf);
} else {
struct sk_buff *skb = ptr;
ret = tun_put_user(tun, tfile, skb, to);
if (unlikely(ret < 0))
kfree_skb(skb);
else
consume_skb(skb);
}
return ret;
}
static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct file *file = iocb->ki_filp;
struct tun_file *tfile = file->private_data;
struct tun_struct *tun = tun_get(tfile);
ssize_t len = iov_iter_count(to), ret;
if (!tun)
return -EBADFD;
ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL);
ret = min_t(ssize_t, ret, len);
if (ret > 0)
iocb->ki_pos = ret;
tun_put(tun);
return ret;
}
static void tun_prog_free(struct rcu_head *rcu)
{
struct tun_prog *prog = container_of(rcu, struct tun_prog, rcu);
bpf_prog_destroy(prog->prog);
kfree(prog);
}
static int __tun_set_ebpf(struct tun_struct *tun,
struct tun_prog __rcu **prog_p,
struct bpf_prog *prog)
{
struct tun_prog *old, *new = NULL;
if (prog) {
new = kmalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return -ENOMEM;
new->prog = prog;
}
spin_lock_bh(&tun->lock);
old = rcu_dereference_protected(*prog_p,
lockdep_is_held(&tun->lock));
rcu_assign_pointer(*prog_p, new);
spin_unlock_bh(&tun->lock);
if (old)
call_rcu(&old->rcu, tun_prog_free);
return 0;
}
static void tun_free_netdev(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
BUG_ON(!(list_empty(&tun->disabled)));
tun: fix memory leak in error path syzbot reported a warning [1] that triggered after recent Jiri patch. This exposes a bug that we hit already in the past (see commit ff244c6b29b1 ("tun: handle register_netdevice() failures properly") for details) tun uses priv->destructor without an ndo_init() method. register_netdevice() can return an error, but will not call priv->destructor() in some cases. Jiri recent patch added one more. A long term fix would be to transfer the initialization of what we destroy in ->destructor() in the ndo_init() This looks a bit risky given the complexity of tun driver. A simpler fix is to detect after the failed register_netdevice() if the tun_free_netdev() function was called already. [1] ODEBUG: free active (active state 0) object type: timer_list hint: tun_flow_cleanup+0x0/0x280 drivers/net/tun.c:457 WARNING: CPU: 0 PID: 8653 at lib/debugobjects.c:481 debug_print_object+0x168/0x250 lib/debugobjects.c:481 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8653 Comm: syz-executor976 Not tainted 5.4.0-rc1-next-20191004 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2dc/0x755 kernel/panic.c:220 __warn.cold+0x2f/0x3c kernel/panic.c:581 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 RIP: 0010:debug_print_object+0x168/0x250 lib/debugobjects.c:481 Code: dd 80 b9 e6 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 80 b9 e6 87 48 c7 c7 e0 ae e6 87 e8 80 84 ff fd <0f> 0b 83 05 e3 ee 80 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3 RSP: 0018:ffff888095997a28 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815cb526 RDI: ffffed1012b32f37 RBP: ffff888095997a68 R08: ffff8880a92ac580 R09: ffffed1015d04101 R10: ffffed1015d04100 R11: ffff8880ae820807 R12: 0000000000000001 R13: ffffffff88fb5340 R14: ffffffff81627110 R15: ffff8880aa41eab8 __debug_check_no_obj_freed lib/debugobjects.c:963 [inline] debug_check_no_obj_freed+0x2d4/0x43f lib/debugobjects.c:994 kfree+0xf8/0x2c0 mm/slab.c:3755 kvfree+0x61/0x70 mm/util.c:593 netdev_freemem net/core/dev.c:9384 [inline] free_netdev+0x39d/0x450 net/core/dev.c:9533 tun_set_iff drivers/net/tun.c:2871 [inline] __tun_chr_ioctl+0x317b/0x3f30 drivers/net/tun.c:3075 tun_chr_ioctl+0x2b/0x40 drivers/net/tun.c:3355 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:539 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726 ksys_ioctl+0xab/0xd0 fs/ioctl.c:743 __do_sys_ioctl fs/ioctl.c:750 [inline] __se_sys_ioctl fs/ioctl.c:748 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441439 Code: e8 9c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff61c37438 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441439 RDX: 0000000020000400 RSI: 00000000400454ca RDI: 0000000000000004 RBP: 00007fff61c37470 R08: 0000000000000001 R09: 0000000100000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jiri Pirko <jiri@mellanox.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-07 19:21:05 +00:00
free_percpu(dev->tstats);
/* We clear tstats so that tun_set_iff() can tell if
tun: fix memory leak in error path syzbot reported a warning [1] that triggered after recent Jiri patch. This exposes a bug that we hit already in the past (see commit ff244c6b29b1 ("tun: handle register_netdevice() failures properly") for details) tun uses priv->destructor without an ndo_init() method. register_netdevice() can return an error, but will not call priv->destructor() in some cases. Jiri recent patch added one more. A long term fix would be to transfer the initialization of what we destroy in ->destructor() in the ndo_init() This looks a bit risky given the complexity of tun driver. A simpler fix is to detect after the failed register_netdevice() if the tun_free_netdev() function was called already. [1] ODEBUG: free active (active state 0) object type: timer_list hint: tun_flow_cleanup+0x0/0x280 drivers/net/tun.c:457 WARNING: CPU: 0 PID: 8653 at lib/debugobjects.c:481 debug_print_object+0x168/0x250 lib/debugobjects.c:481 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8653 Comm: syz-executor976 Not tainted 5.4.0-rc1-next-20191004 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2dc/0x755 kernel/panic.c:220 __warn.cold+0x2f/0x3c kernel/panic.c:581 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 RIP: 0010:debug_print_object+0x168/0x250 lib/debugobjects.c:481 Code: dd 80 b9 e6 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 80 b9 e6 87 48 c7 c7 e0 ae e6 87 e8 80 84 ff fd <0f> 0b 83 05 e3 ee 80 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3 RSP: 0018:ffff888095997a28 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815cb526 RDI: ffffed1012b32f37 RBP: ffff888095997a68 R08: ffff8880a92ac580 R09: ffffed1015d04101 R10: ffffed1015d04100 R11: ffff8880ae820807 R12: 0000000000000001 R13: ffffffff88fb5340 R14: ffffffff81627110 R15: ffff8880aa41eab8 __debug_check_no_obj_freed lib/debugobjects.c:963 [inline] debug_check_no_obj_freed+0x2d4/0x43f lib/debugobjects.c:994 kfree+0xf8/0x2c0 mm/slab.c:3755 kvfree+0x61/0x70 mm/util.c:593 netdev_freemem net/core/dev.c:9384 [inline] free_netdev+0x39d/0x450 net/core/dev.c:9533 tun_set_iff drivers/net/tun.c:2871 [inline] __tun_chr_ioctl+0x317b/0x3f30 drivers/net/tun.c:3075 tun_chr_ioctl+0x2b/0x40 drivers/net/tun.c:3355 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:539 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726 ksys_ioctl+0xab/0xd0 fs/ioctl.c:743 __do_sys_ioctl fs/ioctl.c:750 [inline] __se_sys_ioctl fs/ioctl.c:748 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441439 Code: e8 9c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff61c37438 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441439 RDX: 0000000020000400 RSI: 00000000400454ca RDI: 0000000000000004 RBP: 00007fff61c37470 R08: 0000000000000001 R09: 0000000100000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jiri Pirko <jiri@mellanox.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-07 19:21:05 +00:00
* tun_free_netdev() has been called from register_netdevice().
*/
dev->tstats = NULL;
tun: fix memory leak in error path syzbot reported a warning [1] that triggered after recent Jiri patch. This exposes a bug that we hit already in the past (see commit ff244c6b29b1 ("tun: handle register_netdevice() failures properly") for details) tun uses priv->destructor without an ndo_init() method. register_netdevice() can return an error, but will not call priv->destructor() in some cases. Jiri recent patch added one more. A long term fix would be to transfer the initialization of what we destroy in ->destructor() in the ndo_init() This looks a bit risky given the complexity of tun driver. A simpler fix is to detect after the failed register_netdevice() if the tun_free_netdev() function was called already. [1] ODEBUG: free active (active state 0) object type: timer_list hint: tun_flow_cleanup+0x0/0x280 drivers/net/tun.c:457 WARNING: CPU: 0 PID: 8653 at lib/debugobjects.c:481 debug_print_object+0x168/0x250 lib/debugobjects.c:481 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8653 Comm: syz-executor976 Not tainted 5.4.0-rc1-next-20191004 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2dc/0x755 kernel/panic.c:220 __warn.cold+0x2f/0x3c kernel/panic.c:581 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 RIP: 0010:debug_print_object+0x168/0x250 lib/debugobjects.c:481 Code: dd 80 b9 e6 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 80 b9 e6 87 48 c7 c7 e0 ae e6 87 e8 80 84 ff fd <0f> 0b 83 05 e3 ee 80 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3 RSP: 0018:ffff888095997a28 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815cb526 RDI: ffffed1012b32f37 RBP: ffff888095997a68 R08: ffff8880a92ac580 R09: ffffed1015d04101 R10: ffffed1015d04100 R11: ffff8880ae820807 R12: 0000000000000001 R13: ffffffff88fb5340 R14: ffffffff81627110 R15: ffff8880aa41eab8 __debug_check_no_obj_freed lib/debugobjects.c:963 [inline] debug_check_no_obj_freed+0x2d4/0x43f lib/debugobjects.c:994 kfree+0xf8/0x2c0 mm/slab.c:3755 kvfree+0x61/0x70 mm/util.c:593 netdev_freemem net/core/dev.c:9384 [inline] free_netdev+0x39d/0x450 net/core/dev.c:9533 tun_set_iff drivers/net/tun.c:2871 [inline] __tun_chr_ioctl+0x317b/0x3f30 drivers/net/tun.c:3075 tun_chr_ioctl+0x2b/0x40 drivers/net/tun.c:3355 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:539 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726 ksys_ioctl+0xab/0xd0 fs/ioctl.c:743 __do_sys_ioctl fs/ioctl.c:750 [inline] __se_sys_ioctl fs/ioctl.c:748 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441439 Code: e8 9c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff61c37438 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441439 RDX: 0000000020000400 RSI: 00000000400454ca RDI: 0000000000000004 RBP: 00007fff61c37470 R08: 0000000000000001 R09: 0000000100000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jiri Pirko <jiri@mellanox.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-07 19:21:05 +00:00
tun_flow_uninit(tun);
tun: fix LSM/SELinux labeling of tun/tap devices This patch corrects some problems with LSM/SELinux that were introduced with the multiqueue patchset. The problem stems from the fact that the multiqueue work changed the relationship between the tun device and its associated socket; before the socket persisted for the life of the device, however after the multiqueue changes the socket only persisted for the life of the userspace connection (fd open). For non-persistent devices this is not an issue, but for persistent devices this can cause the tun device to lose its SELinux label. We correct this problem by adding an opaque LSM security blob to the tun device struct which allows us to have the LSM security state, e.g. SELinux labeling information, persist for the lifetime of the tun device. In the process we tweak the LSM hooks to work with this new approach to TUN device/socket labeling and introduce a new LSM hook, security_tun_dev_attach_queue(), to approve requests to attach to a TUN queue via TUNSETQUEUE. The SELinux code has been adjusted to match the new LSM hooks, the other LSMs do not make use of the LSM TUN controls. This patch makes use of the recently added "tun_socket:attach_queue" permission to restrict access to the TUNSETQUEUE operation. On older SELinux policies which do not define the "tun_socket:attach_queue" permission the access control decision for TUNSETQUEUE will be handled according to the SELinux policy's unknown permission setting. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@parisplace.org> Tested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14 07:12:19 +00:00
security_tun_dev_free_security(tun->security);
__tun_set_ebpf(tun, &tun->steering_prog, NULL);
__tun_set_ebpf(tun, &tun->filter_prog, NULL);
}
static void tun_setup(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
tun->owner = INVALID_UID;
tun->group = INVALID_GID;
tun_default_link_ksettings(dev, &tun->link_ksettings);
dev->ethtool_ops = &tun_ethtool_ops;
net: Fix inconsistent teardown and release of private netdev state. Network devices can allocate reasources and private memory using netdev_ops->ndo_init(). However, the release of these resources can occur in one of two different places. Either netdev_ops->ndo_uninit() or netdev->destructor(). The decision of which operation frees the resources depends upon whether it is necessary for all netdev refs to be released before it is safe to perform the freeing. netdev_ops->ndo_uninit() presumably can occur right after the NETDEV_UNREGISTER notifier completes and the unicast and multicast address lists are flushed. netdev->destructor(), on the other hand, does not run until the netdev references all go away. Further complicating the situation is that netdev->destructor() almost universally does also a free_netdev(). This creates a problem for the logic in register_netdevice(). Because all callers of register_netdevice() manage the freeing of the netdev, and invoke free_netdev(dev) if register_netdevice() fails. If netdev_ops->ndo_init() succeeds, but something else fails inside of register_netdevice(), it does call ndo_ops->ndo_uninit(). But it is not able to invoke netdev->destructor(). This is because netdev->destructor() will do a free_netdev() and then the caller of register_netdevice() will do the same. However, this means that the resources that would normally be released by netdev->destructor() will not be. Over the years drivers have added local hacks to deal with this, by invoking their destructor parts by hand when register_netdevice() fails. Many drivers do not try to deal with this, and instead we have leaks. Let's close this hole by formalizing the distinction between what private things need to be freed up by netdev->destructor() and whether the driver needs unregister_netdevice() to perform the free_netdev(). netdev->priv_destructor() performs all actions to free up the private resources that used to be freed by netdev->destructor(), except for free_netdev(). netdev->needs_free_netdev is a boolean that indicates whether free_netdev() should be done at the end of unregister_netdevice(). Now, register_netdevice() can sanely release all resources after ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit() and netdev->priv_destructor(). And at the end of unregister_netdevice(), we invoke netdev->priv_destructor() and optionally call free_netdev(). Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-08 16:52:56 +00:00
dev->needs_free_netdev = true;
dev->priv_destructor = tun_free_netdev;
/* We prefer our own queue length */
dev->tx_queue_len = TUN_READQ_SIZE;
}
/* Trivial set of netlink ops to allow deleting tun or tap
* device with netlink.
*/
static int tun_validate(struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
NL_SET_ERR_MSG(extack,
"tun/tap creation via rtnetlink is not supported.");
return -EOPNOTSUPP;
}
static size_t tun_get_size(const struct net_device *dev)
{
BUILD_BUG_ON(sizeof(u32) != sizeof(uid_t));
BUILD_BUG_ON(sizeof(u32) != sizeof(gid_t));
return nla_total_size(sizeof(uid_t)) + /* OWNER */
nla_total_size(sizeof(gid_t)) + /* GROUP */
nla_total_size(sizeof(u8)) + /* TYPE */
nla_total_size(sizeof(u8)) + /* PI */
nla_total_size(sizeof(u8)) + /* VNET_HDR */
nla_total_size(sizeof(u8)) + /* PERSIST */
nla_total_size(sizeof(u8)) + /* MULTI_QUEUE */
nla_total_size(sizeof(u32)) + /* NUM_QUEUES */
nla_total_size(sizeof(u32)) + /* NUM_DISABLED_QUEUES */
0;
}
static int tun_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
if (nla_put_u8(skb, IFLA_TUN_TYPE, tun->flags & TUN_TYPE_MASK))
goto nla_put_failure;
if (uid_valid(tun->owner) &&
nla_put_u32(skb, IFLA_TUN_OWNER,
from_kuid_munged(current_user_ns(), tun->owner)))
goto nla_put_failure;
if (gid_valid(tun->group) &&
nla_put_u32(skb, IFLA_TUN_GROUP,
from_kgid_munged(current_user_ns(), tun->group)))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_TUN_PI, !(tun->flags & IFF_NO_PI)))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_TUN_VNET_HDR, !!(tun->flags & IFF_VNET_HDR)))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_TUN_PERSIST, !!(tun->flags & IFF_PERSIST)))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_TUN_MULTI_QUEUE,
!!(tun->flags & IFF_MULTI_QUEUE)))
goto nla_put_failure;
if (tun->flags & IFF_MULTI_QUEUE) {
if (nla_put_u32(skb, IFLA_TUN_NUM_QUEUES, tun->numqueues))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_TUN_NUM_DISABLED_QUEUES,
tun->numdisabled))
goto nla_put_failure;
}
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static struct rtnl_link_ops tun_link_ops __read_mostly = {
.kind = DRV_NAME,
.priv_size = sizeof(struct tun_struct),
.setup = tun_setup,
.validate = tun_validate,
.get_size = tun_get_size,
.fill_info = tun_fill_info,
};
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
static void tun_sock_write_space(struct sock *sk)
{
struct tun_file *tfile;
net: sock_def_readable() and friends RCU conversion sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we need two atomic operations (and associated dirtying) per incoming packet. RCU conversion is pretty much needed : 1) Add a new structure, called "struct socket_wq" to hold all fields that will need rcu_read_lock() protection (currently: a wait_queue_head_t and a struct fasync_struct pointer). [Future patch will add a list anchor for wakeup coalescing] 2) Attach one of such structure to each "struct socket" created in sock_alloc_inode(). 3) Respect RCU grace period when freeing a "struct socket_wq" 4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct socket_wq" 5) Change sk_sleep() function to use new sk->sk_wq instead of sk->sk_sleep 6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside a rcu_read_lock() section. 7) Change all sk_has_sleeper() callers to : - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock) - Use wq_has_sleeper() to eventually wakeup tasks. - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock) 8) sock_wake_async() is modified to use rcu protection as well. 9) Exceptions : macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq" instead of dynamically allocated ones. They dont need rcu freeing. Some cleanups or followups are probably needed, (possible sk_callback_lock conversion to a spinlock for example...). Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-29 11:01:49 +00:00
wait_queue_head_t *wqueue;
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
if (!sock_writeable(sk))
return;
if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
return;
net: sock_def_readable() and friends RCU conversion sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we need two atomic operations (and associated dirtying) per incoming packet. RCU conversion is pretty much needed : 1) Add a new structure, called "struct socket_wq" to hold all fields that will need rcu_read_lock() protection (currently: a wait_queue_head_t and a struct fasync_struct pointer). [Future patch will add a list anchor for wakeup coalescing] 2) Attach one of such structure to each "struct socket" created in sock_alloc_inode(). 3) Respect RCU grace period when freeing a "struct socket_wq" 4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct socket_wq" 5) Change sk_sleep() function to use new sk->sk_wq instead of sk->sk_sleep 6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside a rcu_read_lock() section. 7) Change all sk_has_sleeper() callers to : - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock) - Use wq_has_sleeper() to eventually wakeup tasks. - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock) 8) sock_wake_async() is modified to use rcu protection as well. 9) Exceptions : macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq" instead of dynamically allocated ones. They dont need rcu freeing. Some cleanups or followups are probably needed, (possible sk_callback_lock conversion to a spinlock for example...). Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-29 11:01:49 +00:00
wqueue = sk_sleep(sk);
if (wqueue && waitqueue_active(wqueue))
wake_up_interruptible_sync_poll(wqueue, EPOLLOUT |
EPOLLWRNORM | EPOLLWRBAND);
tfile = container_of(sk, struct tun_file, sk);
kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
}
static void tun_put_page(struct tun_page *tpage)
{
if (tpage->page)
__page_frag_cache_drain(tpage->page, tpage->count);
}
static int tun_xdp_one(struct tun_struct *tun,
struct tun_file *tfile,
struct xdp_buff *xdp, int *flush,
struct tun_page *tpage)
{
tun: remove skb access after netif_receive_skb In tun.c skb->len was accessed while doing stats accounting after a call to netif_receive_skb. We can not access skb after this call because buffers may be dropped. The fix for this bug would be to store skb->len in local variable and then use it after netif_receive_skb(). IMO using xdp data size for accounting bytes will be better because input for tun_xdp_one() is xdp_buff. Hence this patch: - fixes a bug by removing skb access after netif_receive_skb() - uses xdp data size for accounting bytes [613.019057] BUG: KASAN: use-after-free in tun_sendmsg+0x77c/0xc50 [tun] [613.021062] Read of size 4 at addr ffff8881da9ab7c0 by task vhost-1115/1155 [613.023073] [613.024003] CPU: 0 PID: 1155 Comm: vhost-1115 Not tainted 4.20.0-rc3-vm+ #232 [613.026029] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [613.029116] Call Trace: [613.031145] dump_stack+0x5b/0x90 [613.032219] print_address_description+0x6c/0x23c [613.034156] ? tun_sendmsg+0x77c/0xc50 [tun] [613.036141] kasan_report.cold.5+0x241/0x308 [613.038125] tun_sendmsg+0x77c/0xc50 [tun] [613.040109] ? tun_get_user+0x1960/0x1960 [tun] [613.042094] ? __isolate_free_page+0x270/0x270 [613.045173] vhost_tx_batch.isra.14+0xeb/0x1f0 [vhost_net] [613.047127] ? peek_head_len.part.13+0x90/0x90 [vhost_net] [613.049096] ? get_tx_bufs+0x5a/0x2c0 [vhost_net] [613.051106] ? vhost_enable_notify+0x2d8/0x420 [vhost] [613.053139] handle_tx_copy+0x2d0/0x8f0 [vhost_net] [613.053139] ? vhost_net_buf_peek+0x340/0x340 [vhost_net] [613.053139] ? __mutex_lock+0x8d9/0xb30 [613.053139] ? finish_task_switch+0x8f/0x3f0 [613.053139] ? handle_tx+0x32/0x120 [vhost_net] [613.053139] ? mutex_trylock+0x110/0x110 [613.053139] ? finish_task_switch+0xcf/0x3f0 [613.053139] ? finish_task_switch+0x240/0x3f0 [613.053139] ? __switch_to_asm+0x34/0x70 [613.053139] ? __switch_to_asm+0x40/0x70 [613.053139] ? __schedule+0x506/0xf10 [613.053139] handle_tx+0xc7/0x120 [vhost_net] [613.053139] vhost_worker+0x166/0x200 [vhost] [613.053139] ? vhost_dev_init+0x580/0x580 [vhost] [613.053139] ? __kthread_parkme+0x77/0x90 [613.053139] ? vhost_dev_init+0x580/0x580 [vhost] [613.053139] kthread+0x1b1/0x1d0 [613.053139] ? kthread_park+0xb0/0xb0 [613.053139] ret_from_fork+0x35/0x40 [613.088705] [613.088705] Allocated by task 1155: [613.088705] kasan_kmalloc+0xbf/0xe0 [613.088705] kmem_cache_alloc+0xdc/0x220 [613.088705] __build_skb+0x2a/0x160 [613.088705] build_skb+0x14/0xc0 [613.088705] tun_sendmsg+0x4f0/0xc50 [tun] [613.088705] vhost_tx_batch.isra.14+0xeb/0x1f0 [vhost_net] [613.088705] handle_tx_copy+0x2d0/0x8f0 [vhost_net] [613.088705] handle_tx+0xc7/0x120 [vhost_net] [613.088705] vhost_worker+0x166/0x200 [vhost] [613.088705] kthread+0x1b1/0x1d0 [613.088705] ret_from_fork+0x35/0x40 [613.088705] [613.088705] Freed by task 1155: [613.088705] __kasan_slab_free+0x12e/0x180 [613.088705] kmem_cache_free+0xa0/0x230 [613.088705] ip6_mc_input+0x40f/0x5a0 [613.088705] ipv6_rcv+0xc9/0x1e0 [613.088705] __netif_receive_skb_one_core+0xc1/0x100 [613.088705] netif_receive_skb_internal+0xc4/0x270 [613.088705] br_pass_frame_up+0x2b9/0x2e0 [613.088705] br_handle_frame_finish+0x2fb/0x7a0 [613.088705] br_handle_frame+0x30f/0x6c0 [613.088705] __netif_receive_skb_core+0x61a/0x15b0 [613.088705] __netif_receive_skb_one_core+0x8e/0x100 [613.088705] netif_receive_skb_internal+0xc4/0x270 [613.088705] tun_sendmsg+0x738/0xc50 [tun] [613.088705] vhost_tx_batch.isra.14+0xeb/0x1f0 [vhost_net] [613.088705] handle_tx_copy+0x2d0/0x8f0 [vhost_net] [613.088705] handle_tx+0xc7/0x120 [vhost_net] [613.088705] vhost_worker+0x166/0x200 [vhost] [613.088705] kthread+0x1b1/0x1d0 [613.088705] ret_from_fork+0x35/0x40 [613.088705] [613.088705] The buggy address belongs to the object at ffff8881da9ab740 [613.088705] which belongs to the cache skbuff_head_cache of size 232 Fixes: 043d222f93ab ("tuntap: accept an array of XDP buffs through sendmsg()") Reviewed-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-03 09:09:24 +00:00
unsigned int datasize = xdp->data_end - xdp->data;
struct tun_xdp_hdr *hdr = xdp->data_hard_start;
struct virtio_net_hdr *gso = &hdr->gso;
struct bpf_prog *xdp_prog;
struct sk_buff *skb = NULL;
u32 rxhash = 0, act;
int buflen = hdr->buflen;
int err = 0;
bool skb_xdp = false;
struct page *page;
xdp_prog = rcu_dereference(tun->xdp_prog);
if (xdp_prog) {
if (gso->gso_type) {
skb_xdp = true;
goto build;
}
xdp_set_data_meta_invalid(xdp);
xdp->rxq = &tfile->xdp_rxq;
xdp->frame_sz = buflen;
act = bpf_prog_run_xdp(xdp_prog, xdp);
err = tun_xdp_act(tun, xdp_prog, xdp, act);
if (err < 0) {
put_page(virt_to_head_page(xdp->data));
return err;
}
switch (err) {
case XDP_REDIRECT:
*flush = true;
fallthrough;
case XDP_TX:
return 0;
case XDP_PASS:
break;
default:
page = virt_to_head_page(xdp->data);
if (tpage->page == page) {
++tpage->count;
} else {
tun_put_page(tpage);
tpage->page = page;
tpage->count = 1;
}
return 0;
}
}
build:
skb = build_skb(xdp->data_hard_start, buflen);
if (!skb) {
err = -ENOMEM;
goto out;
}
skb_reserve(skb, xdp->data - xdp->data_hard_start);
skb_put(skb, xdp->data_end - xdp->data);
if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun))) {
atomic_long_inc(&tun->rx_frame_errors);
kfree_skb(skb);
err = -EINVAL;
goto out;
}
skb->protocol = eth_type_trans(skb, tun->dev);
skb_reset_network_header(skb);
skb_probe_transport_header(skb);
skb_record_rx_queue(skb, tfile->queue_index);
if (skb_xdp) {
err = do_xdp_generic(xdp_prog, skb);
if (err != XDP_PASS)
goto out;
}
if (!rcu_dereference(tun->steering_prog) && tun->numqueues > 1 &&
!tfile->detached)
rxhash = __skb_get_hash_symmetric(skb);
netif_receive_skb(skb);
/* No need to disable preemption here since this function is
* always called with bh disabled
*/
dev_sw_netstats_rx_add(tun->dev, datasize);
if (rxhash)
tun_flow_update(tun, rxhash, tfile);
out:
return err;
}
static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
{
int ret, i;
struct tun_file *tfile = container_of(sock, struct tun_file, socket);
struct tun_struct *tun = tun_get(tfile);
struct tun_msg_ctl *ctl = m->msg_control;
struct xdp_buff *xdp;
if (!tun)
return -EBADFD;
if (ctl && (ctl->type == TUN_MSG_PTR)) {
struct tun_page tpage;
int n = ctl->num;
int flush = 0;
memset(&tpage, 0, sizeof(tpage));
local_bh_disable();
rcu_read_lock();
for (i = 0; i < n; i++) {
xdp = &((struct xdp_buff *)ctl->ptr)[i];
tun_xdp_one(tun, tfile, xdp, &flush, &tpage);
}
if (flush)
xdp: Use bulking for non-map XDP_REDIRECT and consolidate code paths Since the bulk queue used by XDP_REDIRECT now lives in struct net_device, we can re-use the bulking for the non-map version of the bpf_redirect() helper. This is a simple matter of having xdp_do_redirect_slow() queue the frame on the bulk queue instead of sending it out with __bpf_tx_xdp(). Unfortunately we can't make the bpf_redirect() helper return an error if the ifindex doesn't exit (as bpf_redirect_map() does), because we don't have a reference to the network namespace of the ingress device at the time the helper is called. So we have to leave it as-is and keep the device lookup in xdp_do_redirect_slow(). Since this leaves less reason to have the non-map redirect code in a separate function, so we get rid of the xdp_do_redirect_slow() function entirely. This does lose us the tracepoint disambiguation, but fortunately the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint entry structures. This means both can contain a map index, so we can just amend the tracepoint definitions so we always emit the xdp_redirect(_err) tracepoints, but with the map ID only populated if a map is present. This means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep the definitions around in case someone is still listening for them. With this change, the performance of the xdp_redirect sample program goes from 5Mpps to 8.4Mpps (a 68% increase). Since the flush functions are no longer map-specific, rename the flush() functions to drop _map from their names. One of the renamed functions is the xdp_do_flush_map() callback used in all the xdp-enabled drivers. To keep from having to update all drivers, use a #define to keep the old name working, and only update the virtual drivers in this patch. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/157918768505.1458396.17518057312953572912.stgit@toke.dk
2020-01-16 15:14:45 +00:00
xdp_do_flush();
rcu_read_unlock();
local_bh_enable();
tun_put_page(&tpage);
ret = total_len;
goto out;
}
ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter,
m->msg_flags & MSG_DONTWAIT,
m->msg_flags & MSG_MORE);
out:
tun_put(tun);
return ret;
}
static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
int flags)
{
struct tun_file *tfile = container_of(sock, struct tun_file, socket);
struct tun_struct *tun = tun_get(tfile);
void *ptr = m->msg_control;
int ret;
if (!tun) {
ret = -EBADFD;
goto out_free;
}
if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
ret = -EINVAL;
goto out_put_tun;
}
if (flags & MSG_ERRQUEUE) {
ret = sock_recv_errqueue(sock->sk, m, total_len,
SOL_PACKET, TUN_TX_TIMESTAMP);
goto out;
}
ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, ptr);
if (ret > (ssize_t)total_len) {
m->msg_flags |= MSG_TRUNC;
ret = flags & MSG_TRUNC ? ret : total_len;
}
out:
tun_put(tun);
return ret;
out_put_tun:
tun_put(tun);
out_free:
tun_ptr_free(ptr);
return ret;
}
static int tun_ptr_peek_len(void *ptr)
{
if (likely(ptr)) {
if (tun_is_xdp_frame(ptr)) {
struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
return xdpf->len;
}
return __skb_array_len_with_tag(ptr);
} else {
return 0;
}
}
static int tun_peek_len(struct socket *sock)
{
struct tun_file *tfile = container_of(sock, struct tun_file, socket);
struct tun_struct *tun;
int ret = 0;
tun = tun_get(tfile);
if (!tun)
return 0;
ret = PTR_RING_PEEK_CALL(&tfile->tx_ring, tun_ptr_peek_len);
tun_put(tun);
return ret;
}
/* Ops structure to mimic raw sockets with tun */
static const struct proto_ops tun_socket_ops = {
.peek_len = tun_peek_len,
.sendmsg = tun_sendmsg,
.recvmsg = tun_recvmsg,
};
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
static struct proto tun_proto = {
.name = "tun",
.owner = THIS_MODULE,
.obj_size = sizeof(struct tun_file),
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
};
static int tun_flags(struct tun_struct *tun)
{
return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
}
static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tun_struct *tun = netdev_priv(to_net_dev(dev));
return sprintf(buf, "0x%x\n", tun_flags(tun));
}
static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tun_struct *tun = netdev_priv(to_net_dev(dev));
return uid_valid(tun->owner)?
sprintf(buf, "%u\n",
from_kuid_munged(current_user_ns(), tun->owner)):
sprintf(buf, "-1\n");
}
static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tun_struct *tun = netdev_priv(to_net_dev(dev));
return gid_valid(tun->group) ?
sprintf(buf, "%u\n",
from_kgid_munged(current_user_ns(), tun->group)):
sprintf(buf, "-1\n");
}
static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
static struct attribute *tun_dev_attrs[] = {
&dev_attr_tun_flags.attr,
&dev_attr_owner.attr,
&dev_attr_group.attr,
NULL
};
static const struct attribute_group tun_attr_group = {
.attrs = tun_dev_attrs
};
static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
{
struct tun_struct *tun;
struct tun_file *tfile = file->private_data;
struct net_device *dev;
int err;
if (tfile->detached)
return -EINVAL;
if ((ifr->ifr_flags & IFF_NAPI_FRAGS)) {
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (!(ifr->ifr_flags & IFF_NAPI) ||
(ifr->ifr_flags & TUN_TYPE_MASK) != IFF_TAP)
return -EINVAL;
}
dev = __dev_get_by_name(net, ifr->ifr_name);
if (dev) {
if (ifr->ifr_flags & IFF_TUN_EXCL)
return -EBUSY;
if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
tun = netdev_priv(dev);
else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
tun = netdev_priv(dev);
else
return -EINVAL;
if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
!!(tun->flags & IFF_MULTI_QUEUE))
return -EINVAL;
if (tun_not_capable(tun))
return -EPERM;
tun: fix LSM/SELinux labeling of tun/tap devices This patch corrects some problems with LSM/SELinux that were introduced with the multiqueue patchset. The problem stems from the fact that the multiqueue work changed the relationship between the tun device and its associated socket; before the socket persisted for the life of the device, however after the multiqueue changes the socket only persisted for the life of the userspace connection (fd open). For non-persistent devices this is not an issue, but for persistent devices this can cause the tun device to lose its SELinux label. We correct this problem by adding an opaque LSM security blob to the tun device struct which allows us to have the LSM security state, e.g. SELinux labeling information, persist for the lifetime of the tun device. In the process we tweak the LSM hooks to work with this new approach to TUN device/socket labeling and introduce a new LSM hook, security_tun_dev_attach_queue(), to approve requests to attach to a TUN queue via TUNSETQUEUE. The SELinux code has been adjusted to match the new LSM hooks, the other LSMs do not make use of the LSM TUN controls. This patch makes use of the recently added "tun_socket:attach_queue" permission to restrict access to the TUNSETQUEUE operation. On older SELinux policies which do not define the "tun_socket:attach_queue" permission the access control decision for TUNSETQUEUE will be handled according to the SELinux policy's unknown permission setting. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@parisplace.org> Tested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14 07:12:19 +00:00
err = security_tun_dev_open(tun->security);
if (err < 0)
return err;
err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER,
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
ifr->ifr_flags & IFF_NAPI,
tun: fix use-after-free when register netdev failed I got a UAF repport in tun driver when doing fuzzy test: [ 466.269490] ================================================================== [ 466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0 [ 466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699 [ 466.271810] [ 466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427 [ 466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 466.271838] Call Trace: [ 466.271858] dump_stack+0xca/0x13e [ 466.271871] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271890] print_address_description+0x79/0x440 [ 466.271906] ? vprintk_func+0x5e/0xf0 [ 466.271920] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271935] __kasan_report+0x15c/0x1df [ 466.271958] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271976] kasan_report+0xe/0x20 [ 466.271987] tun_chr_read_iter+0x2ca/0x2d0 [ 466.272013] do_iter_readv_writev+0x4b7/0x740 [ 466.272032] ? default_llseek+0x2d0/0x2d0 [ 466.272072] do_iter_read+0x1c5/0x5e0 [ 466.272110] vfs_readv+0x108/0x180 [ 466.299007] ? compat_rw_copy_check_uvector+0x440/0x440 [ 466.299020] ? fsnotify+0x888/0xd50 [ 466.299040] ? __fsnotify_parent+0xd0/0x350 [ 466.299064] ? fsnotify_first_mark+0x1e0/0x1e0 [ 466.304548] ? vfs_write+0x264/0x510 [ 466.304569] ? ksys_write+0x101/0x210 [ 466.304591] ? do_preadv+0x116/0x1a0 [ 466.304609] do_preadv+0x116/0x1a0 [ 466.309829] do_syscall_64+0xc8/0x600 [ 466.309849] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.309861] RIP: 0033:0x4560f9 [ 466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127 [ 466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9 [ 466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003 [ 466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000 [ 466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10 [ 466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000 [ 466.323057] [ 466.323064] Allocated by task 2605: [ 466.335165] save_stack+0x19/0x80 [ 466.336240] __kasan_kmalloc.constprop.8+0xa0/0xd0 [ 466.337755] kmem_cache_alloc+0xe8/0x320 [ 466.339050] getname_flags+0xca/0x560 [ 466.340229] user_path_at_empty+0x2c/0x50 [ 466.341508] vfs_statx+0xe6/0x190 [ 466.342619] __do_sys_newstat+0x81/0x100 [ 466.343908] do_syscall_64+0xc8/0x600 [ 466.345303] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.347034] [ 466.347517] Freed by task 2605: [ 466.348471] save_stack+0x19/0x80 [ 466.349476] __kasan_slab_free+0x12e/0x180 [ 466.350726] kmem_cache_free+0xc8/0x430 [ 466.351874] putname+0xe2/0x120 [ 466.352921] filename_lookup+0x257/0x3e0 [ 466.354319] vfs_statx+0xe6/0x190 [ 466.355498] __do_sys_newstat+0x81/0x100 [ 466.356889] do_syscall_64+0xc8/0x600 [ 466.358037] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.359567] [ 466.360050] The buggy address belongs to the object at ffff888372139100 [ 466.360050] which belongs to the cache names_cache of size 4096 [ 466.363735] The buggy address is located 336 bytes inside of [ 466.363735] 4096-byte region [ffff888372139100, ffff88837213a100) [ 466.367179] The buggy address belongs to the page: [ 466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0 [ 466.371582] flags: 0x2fffff80010200(slab|head) [ 466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00 [ 466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 [ 466.377778] page dumped because: kasan: bad access detected [ 466.379730] [ 466.380288] Memory state around the buggy address: [ 466.381844] ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.384009] ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.388257] ^ [ 466.390234] ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.392512] ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.394667] ================================================================== tun_chr_read_iter() accessed the memory which freed by free_netdev() called by tun_set_iff(): CPUA CPUB tun_set_iff() alloc_netdev_mqs() tun_attach() tun_chr_read_iter() tun_get() tun_do_read() tun_ring_recv() register_netdevice() <-- inject error goto err_detach tun_detach_all() <-- set RCV_SHUTDOWN free_netdev() <-- called from err_free_dev path netdev_freemem() <-- free the memory without check refcount (In this path, the refcount cannot prevent freeing the memory of dev, and the memory will be used by dev_put() called by tun_chr_read_iter() on CPUB.) (Break from tun_ring_recv(), because RCV_SHUTDOWN is set) tun_put() dev_put() <-- use the memory freed by netdev_freemem() Put the publishing of tfile->tun after register_netdevice(), so tun_get() won't get the tun pointer that freed by err_detach path if register_netdevice() failed. Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice") Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-10 10:56:57 +00:00
ifr->ifr_flags & IFF_NAPI_FRAGS, true);
if (err < 0)
return err;
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
if (tun->flags & IFF_MULTI_QUEUE &&
(tun->numqueues + tun->numdisabled > 1)) {
/* One or more queue has already been attached, no need
* to initialize the device again.
*/
netdev_state_change(dev);
return 0;
}
tun->flags = (tun->flags & ~TUN_FEATURES) |
(ifr->ifr_flags & TUN_FEATURES);
netdev_state_change(dev);
} else {
char *name;
unsigned long flags = 0;
int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
MAX_TAP_QUEUES : 1;
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
err = security_tun_dev_create();
if (err < 0)
return err;
/* Set dev type */
if (ifr->ifr_flags & IFF_TUN) {
/* TUN device */
flags |= IFF_TUN;
name = "tun%d";
} else if (ifr->ifr_flags & IFF_TAP) {
/* TAP device */
flags |= IFF_TAP;
name = "tap%d";
} else
return -EINVAL;
if (*ifr->ifr_name)
name = ifr->ifr_name;
dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
NET_NAME_UNKNOWN, tun_setup, queues,
queues);
if (!dev)
return -ENOMEM;
dev_net_set(dev, net);
dev->rtnl_link_ops = &tun_link_ops;
dev->ifindex = tfile->ifindex;
dev->sysfs_groups[0] = &tun_attr_group;
tun = netdev_priv(dev);
tun->dev = dev;
tun->flags = flags;
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
tun->txflt.count = 0;
tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
tun->align = NET_SKB_PAD;
tun->filter_attached = false;
tun->sndbuf = tfile->socket.sk->sk_sndbuf;
tun->rx_batched = 0;
RCU_INIT_POINTER(tun->steering_prog, NULL);
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
if (!dev->tstats) {
err = -ENOMEM;
goto err_free_dev;
}
spin_lock_init(&tun->lock);
tun: fix LSM/SELinux labeling of tun/tap devices This patch corrects some problems with LSM/SELinux that were introduced with the multiqueue patchset. The problem stems from the fact that the multiqueue work changed the relationship between the tun device and its associated socket; before the socket persisted for the life of the device, however after the multiqueue changes the socket only persisted for the life of the userspace connection (fd open). For non-persistent devices this is not an issue, but for persistent devices this can cause the tun device to lose its SELinux label. We correct this problem by adding an opaque LSM security blob to the tun device struct which allows us to have the LSM security state, e.g. SELinux labeling information, persist for the lifetime of the tun device. In the process we tweak the LSM hooks to work with this new approach to TUN device/socket labeling and introduce a new LSM hook, security_tun_dev_attach_queue(), to approve requests to attach to a TUN queue via TUNSETQUEUE. The SELinux code has been adjusted to match the new LSM hooks, the other LSMs do not make use of the LSM TUN controls. This patch makes use of the recently added "tun_socket:attach_queue" permission to restrict access to the TUNSETQUEUE operation. On older SELinux policies which do not define the "tun_socket:attach_queue" permission the access control decision for TUNSETQUEUE will be handled according to the SELinux policy's unknown permission setting. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@parisplace.org> Tested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14 07:12:19 +00:00
err = security_tun_dev_alloc_security(&tun->security);
if (err < 0)
goto err_free_stat;
tun_net_init(dev);
tun_flow_init(tun);
dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
NETIF_F_HW_VLAN_STAG_TX;
dev->features = dev->hw_features | NETIF_F_LLTX;
dev->vlan_features = dev->features &
~(NETIF_F_HW_VLAN_CTAG_TX |
NETIF_F_HW_VLAN_STAG_TX);
tun->flags = (tun->flags & ~TUN_FEATURES) |
(ifr->ifr_flags & TUN_FEATURES);
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
INIT_LIST_HEAD(&tun->disabled);
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI,
tun: fix use-after-free when register netdev failed I got a UAF repport in tun driver when doing fuzzy test: [ 466.269490] ================================================================== [ 466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0 [ 466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699 [ 466.271810] [ 466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427 [ 466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 466.271838] Call Trace: [ 466.271858] dump_stack+0xca/0x13e [ 466.271871] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271890] print_address_description+0x79/0x440 [ 466.271906] ? vprintk_func+0x5e/0xf0 [ 466.271920] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271935] __kasan_report+0x15c/0x1df [ 466.271958] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271976] kasan_report+0xe/0x20 [ 466.271987] tun_chr_read_iter+0x2ca/0x2d0 [ 466.272013] do_iter_readv_writev+0x4b7/0x740 [ 466.272032] ? default_llseek+0x2d0/0x2d0 [ 466.272072] do_iter_read+0x1c5/0x5e0 [ 466.272110] vfs_readv+0x108/0x180 [ 466.299007] ? compat_rw_copy_check_uvector+0x440/0x440 [ 466.299020] ? fsnotify+0x888/0xd50 [ 466.299040] ? __fsnotify_parent+0xd0/0x350 [ 466.299064] ? fsnotify_first_mark+0x1e0/0x1e0 [ 466.304548] ? vfs_write+0x264/0x510 [ 466.304569] ? ksys_write+0x101/0x210 [ 466.304591] ? do_preadv+0x116/0x1a0 [ 466.304609] do_preadv+0x116/0x1a0 [ 466.309829] do_syscall_64+0xc8/0x600 [ 466.309849] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.309861] RIP: 0033:0x4560f9 [ 466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127 [ 466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9 [ 466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003 [ 466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000 [ 466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10 [ 466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000 [ 466.323057] [ 466.323064] Allocated by task 2605: [ 466.335165] save_stack+0x19/0x80 [ 466.336240] __kasan_kmalloc.constprop.8+0xa0/0xd0 [ 466.337755] kmem_cache_alloc+0xe8/0x320 [ 466.339050] getname_flags+0xca/0x560 [ 466.340229] user_path_at_empty+0x2c/0x50 [ 466.341508] vfs_statx+0xe6/0x190 [ 466.342619] __do_sys_newstat+0x81/0x100 [ 466.343908] do_syscall_64+0xc8/0x600 [ 466.345303] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.347034] [ 466.347517] Freed by task 2605: [ 466.348471] save_stack+0x19/0x80 [ 466.349476] __kasan_slab_free+0x12e/0x180 [ 466.350726] kmem_cache_free+0xc8/0x430 [ 466.351874] putname+0xe2/0x120 [ 466.352921] filename_lookup+0x257/0x3e0 [ 466.354319] vfs_statx+0xe6/0x190 [ 466.355498] __do_sys_newstat+0x81/0x100 [ 466.356889] do_syscall_64+0xc8/0x600 [ 466.358037] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.359567] [ 466.360050] The buggy address belongs to the object at ffff888372139100 [ 466.360050] which belongs to the cache names_cache of size 4096 [ 466.363735] The buggy address is located 336 bytes inside of [ 466.363735] 4096-byte region [ffff888372139100, ffff88837213a100) [ 466.367179] The buggy address belongs to the page: [ 466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0 [ 466.371582] flags: 0x2fffff80010200(slab|head) [ 466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00 [ 466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 [ 466.377778] page dumped because: kasan: bad access detected [ 466.379730] [ 466.380288] Memory state around the buggy address: [ 466.381844] ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.384009] ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.388257] ^ [ 466.390234] ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.392512] ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.394667] ================================================================== tun_chr_read_iter() accessed the memory which freed by free_netdev() called by tun_set_iff(): CPUA CPUB tun_set_iff() alloc_netdev_mqs() tun_attach() tun_chr_read_iter() tun_get() tun_do_read() tun_ring_recv() register_netdevice() <-- inject error goto err_detach tun_detach_all() <-- set RCV_SHUTDOWN free_netdev() <-- called from err_free_dev path netdev_freemem() <-- free the memory without check refcount (In this path, the refcount cannot prevent freeing the memory of dev, and the memory will be used by dev_put() called by tun_chr_read_iter() on CPUB.) (Break from tun_ring_recv(), because RCV_SHUTDOWN is set) tun_put() dev_put() <-- use the memory freed by netdev_freemem() Put the publishing of tfile->tun after register_netdevice(), so tun_get() won't get the tun pointer that freed by err_detach path if register_netdevice() failed. Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice") Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-10 10:56:57 +00:00
ifr->ifr_flags & IFF_NAPI_FRAGS, false);
if (err < 0)
goto err_free_flow;
err = register_netdevice(tun->dev);
if (err < 0)
goto err_detach;
tun: fix use-after-free when register netdev failed I got a UAF repport in tun driver when doing fuzzy test: [ 466.269490] ================================================================== [ 466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0 [ 466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699 [ 466.271810] [ 466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427 [ 466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 466.271838] Call Trace: [ 466.271858] dump_stack+0xca/0x13e [ 466.271871] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271890] print_address_description+0x79/0x440 [ 466.271906] ? vprintk_func+0x5e/0xf0 [ 466.271920] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271935] __kasan_report+0x15c/0x1df [ 466.271958] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271976] kasan_report+0xe/0x20 [ 466.271987] tun_chr_read_iter+0x2ca/0x2d0 [ 466.272013] do_iter_readv_writev+0x4b7/0x740 [ 466.272032] ? default_llseek+0x2d0/0x2d0 [ 466.272072] do_iter_read+0x1c5/0x5e0 [ 466.272110] vfs_readv+0x108/0x180 [ 466.299007] ? compat_rw_copy_check_uvector+0x440/0x440 [ 466.299020] ? fsnotify+0x888/0xd50 [ 466.299040] ? __fsnotify_parent+0xd0/0x350 [ 466.299064] ? fsnotify_first_mark+0x1e0/0x1e0 [ 466.304548] ? vfs_write+0x264/0x510 [ 466.304569] ? ksys_write+0x101/0x210 [ 466.304591] ? do_preadv+0x116/0x1a0 [ 466.304609] do_preadv+0x116/0x1a0 [ 466.309829] do_syscall_64+0xc8/0x600 [ 466.309849] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.309861] RIP: 0033:0x4560f9 [ 466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127 [ 466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9 [ 466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003 [ 466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000 [ 466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10 [ 466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000 [ 466.323057] [ 466.323064] Allocated by task 2605: [ 466.335165] save_stack+0x19/0x80 [ 466.336240] __kasan_kmalloc.constprop.8+0xa0/0xd0 [ 466.337755] kmem_cache_alloc+0xe8/0x320 [ 466.339050] getname_flags+0xca/0x560 [ 466.340229] user_path_at_empty+0x2c/0x50 [ 466.341508] vfs_statx+0xe6/0x190 [ 466.342619] __do_sys_newstat+0x81/0x100 [ 466.343908] do_syscall_64+0xc8/0x600 [ 466.345303] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.347034] [ 466.347517] Freed by task 2605: [ 466.348471] save_stack+0x19/0x80 [ 466.349476] __kasan_slab_free+0x12e/0x180 [ 466.350726] kmem_cache_free+0xc8/0x430 [ 466.351874] putname+0xe2/0x120 [ 466.352921] filename_lookup+0x257/0x3e0 [ 466.354319] vfs_statx+0xe6/0x190 [ 466.355498] __do_sys_newstat+0x81/0x100 [ 466.356889] do_syscall_64+0xc8/0x600 [ 466.358037] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.359567] [ 466.360050] The buggy address belongs to the object at ffff888372139100 [ 466.360050] which belongs to the cache names_cache of size 4096 [ 466.363735] The buggy address is located 336 bytes inside of [ 466.363735] 4096-byte region [ffff888372139100, ffff88837213a100) [ 466.367179] The buggy address belongs to the page: [ 466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0 [ 466.371582] flags: 0x2fffff80010200(slab|head) [ 466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00 [ 466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 [ 466.377778] page dumped because: kasan: bad access detected [ 466.379730] [ 466.380288] Memory state around the buggy address: [ 466.381844] ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.384009] ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.388257] ^ [ 466.390234] ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.392512] ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.394667] ================================================================== tun_chr_read_iter() accessed the memory which freed by free_netdev() called by tun_set_iff(): CPUA CPUB tun_set_iff() alloc_netdev_mqs() tun_attach() tun_chr_read_iter() tun_get() tun_do_read() tun_ring_recv() register_netdevice() <-- inject error goto err_detach tun_detach_all() <-- set RCV_SHUTDOWN free_netdev() <-- called from err_free_dev path netdev_freemem() <-- free the memory without check refcount (In this path, the refcount cannot prevent freeing the memory of dev, and the memory will be used by dev_put() called by tun_chr_read_iter() on CPUB.) (Break from tun_ring_recv(), because RCV_SHUTDOWN is set) tun_put() dev_put() <-- use the memory freed by netdev_freemem() Put the publishing of tfile->tun after register_netdevice(), so tun_get() won't get the tun pointer that freed by err_detach path if register_netdevice() failed. Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice") Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-10 10:56:57 +00:00
/* free_netdev() won't check refcnt, to aovid race
* with dev_put() we need publish tun after registration.
*/
rcu_assign_pointer(tfile->tun, tun);
}
netif_carrier_on(tun->dev);
/* Make sure persistent devices do not get stuck in
* xoff state.
*/
if (netif_running(tun->dev))
netif_tx_wake_all_queues(tun->dev);
strcpy(ifr->ifr_name, tun->dev->name);
return 0;
err_detach:
tun_detach_all(dev);
tun: fix memory leak in error path syzbot reported a warning [1] that triggered after recent Jiri patch. This exposes a bug that we hit already in the past (see commit ff244c6b29b1 ("tun: handle register_netdevice() failures properly") for details) tun uses priv->destructor without an ndo_init() method. register_netdevice() can return an error, but will not call priv->destructor() in some cases. Jiri recent patch added one more. A long term fix would be to transfer the initialization of what we destroy in ->destructor() in the ndo_init() This looks a bit risky given the complexity of tun driver. A simpler fix is to detect after the failed register_netdevice() if the tun_free_netdev() function was called already. [1] ODEBUG: free active (active state 0) object type: timer_list hint: tun_flow_cleanup+0x0/0x280 drivers/net/tun.c:457 WARNING: CPU: 0 PID: 8653 at lib/debugobjects.c:481 debug_print_object+0x168/0x250 lib/debugobjects.c:481 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8653 Comm: syz-executor976 Not tainted 5.4.0-rc1-next-20191004 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2dc/0x755 kernel/panic.c:220 __warn.cold+0x2f/0x3c kernel/panic.c:581 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 RIP: 0010:debug_print_object+0x168/0x250 lib/debugobjects.c:481 Code: dd 80 b9 e6 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 80 b9 e6 87 48 c7 c7 e0 ae e6 87 e8 80 84 ff fd <0f> 0b 83 05 e3 ee 80 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3 RSP: 0018:ffff888095997a28 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815cb526 RDI: ffffed1012b32f37 RBP: ffff888095997a68 R08: ffff8880a92ac580 R09: ffffed1015d04101 R10: ffffed1015d04100 R11: ffff8880ae820807 R12: 0000000000000001 R13: ffffffff88fb5340 R14: ffffffff81627110 R15: ffff8880aa41eab8 __debug_check_no_obj_freed lib/debugobjects.c:963 [inline] debug_check_no_obj_freed+0x2d4/0x43f lib/debugobjects.c:994 kfree+0xf8/0x2c0 mm/slab.c:3755 kvfree+0x61/0x70 mm/util.c:593 netdev_freemem net/core/dev.c:9384 [inline] free_netdev+0x39d/0x450 net/core/dev.c:9533 tun_set_iff drivers/net/tun.c:2871 [inline] __tun_chr_ioctl+0x317b/0x3f30 drivers/net/tun.c:3075 tun_chr_ioctl+0x2b/0x40 drivers/net/tun.c:3355 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:539 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726 ksys_ioctl+0xab/0xd0 fs/ioctl.c:743 __do_sys_ioctl fs/ioctl.c:750 [inline] __se_sys_ioctl fs/ioctl.c:748 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441439 Code: e8 9c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff61c37438 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441439 RDX: 0000000020000400 RSI: 00000000400454ca RDI: 0000000000000004 RBP: 00007fff61c37470 R08: 0000000000000001 R09: 0000000100000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jiri Pirko <jiri@mellanox.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-07 19:21:05 +00:00
/* We are here because register_netdevice() has failed.
* If register_netdevice() already called tun_free_netdev()
* while dealing with the error, dev->stats has been cleared.
tun: fix memory leak in error path syzbot reported a warning [1] that triggered after recent Jiri patch. This exposes a bug that we hit already in the past (see commit ff244c6b29b1 ("tun: handle register_netdevice() failures properly") for details) tun uses priv->destructor without an ndo_init() method. register_netdevice() can return an error, but will not call priv->destructor() in some cases. Jiri recent patch added one more. A long term fix would be to transfer the initialization of what we destroy in ->destructor() in the ndo_init() This looks a bit risky given the complexity of tun driver. A simpler fix is to detect after the failed register_netdevice() if the tun_free_netdev() function was called already. [1] ODEBUG: free active (active state 0) object type: timer_list hint: tun_flow_cleanup+0x0/0x280 drivers/net/tun.c:457 WARNING: CPU: 0 PID: 8653 at lib/debugobjects.c:481 debug_print_object+0x168/0x250 lib/debugobjects.c:481 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8653 Comm: syz-executor976 Not tainted 5.4.0-rc1-next-20191004 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2dc/0x755 kernel/panic.c:220 __warn.cold+0x2f/0x3c kernel/panic.c:581 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 RIP: 0010:debug_print_object+0x168/0x250 lib/debugobjects.c:481 Code: dd 80 b9 e6 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 80 b9 e6 87 48 c7 c7 e0 ae e6 87 e8 80 84 ff fd <0f> 0b 83 05 e3 ee 80 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3 RSP: 0018:ffff888095997a28 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815cb526 RDI: ffffed1012b32f37 RBP: ffff888095997a68 R08: ffff8880a92ac580 R09: ffffed1015d04101 R10: ffffed1015d04100 R11: ffff8880ae820807 R12: 0000000000000001 R13: ffffffff88fb5340 R14: ffffffff81627110 R15: ffff8880aa41eab8 __debug_check_no_obj_freed lib/debugobjects.c:963 [inline] debug_check_no_obj_freed+0x2d4/0x43f lib/debugobjects.c:994 kfree+0xf8/0x2c0 mm/slab.c:3755 kvfree+0x61/0x70 mm/util.c:593 netdev_freemem net/core/dev.c:9384 [inline] free_netdev+0x39d/0x450 net/core/dev.c:9533 tun_set_iff drivers/net/tun.c:2871 [inline] __tun_chr_ioctl+0x317b/0x3f30 drivers/net/tun.c:3075 tun_chr_ioctl+0x2b/0x40 drivers/net/tun.c:3355 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:539 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726 ksys_ioctl+0xab/0xd0 fs/ioctl.c:743 __do_sys_ioctl fs/ioctl.c:750 [inline] __se_sys_ioctl fs/ioctl.c:748 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441439 Code: e8 9c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff61c37438 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441439 RDX: 0000000020000400 RSI: 00000000400454ca RDI: 0000000000000004 RBP: 00007fff61c37470 R08: 0000000000000001 R09: 0000000100000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jiri Pirko <jiri@mellanox.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-07 19:21:05 +00:00
*/
if (!dev->tstats)
tun: fix memory leak in error path syzbot reported a warning [1] that triggered after recent Jiri patch. This exposes a bug that we hit already in the past (see commit ff244c6b29b1 ("tun: handle register_netdevice() failures properly") for details) tun uses priv->destructor without an ndo_init() method. register_netdevice() can return an error, but will not call priv->destructor() in some cases. Jiri recent patch added one more. A long term fix would be to transfer the initialization of what we destroy in ->destructor() in the ndo_init() This looks a bit risky given the complexity of tun driver. A simpler fix is to detect after the failed register_netdevice() if the tun_free_netdev() function was called already. [1] ODEBUG: free active (active state 0) object type: timer_list hint: tun_flow_cleanup+0x0/0x280 drivers/net/tun.c:457 WARNING: CPU: 0 PID: 8653 at lib/debugobjects.c:481 debug_print_object+0x168/0x250 lib/debugobjects.c:481 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8653 Comm: syz-executor976 Not tainted 5.4.0-rc1-next-20191004 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2dc/0x755 kernel/panic.c:220 __warn.cold+0x2f/0x3c kernel/panic.c:581 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 RIP: 0010:debug_print_object+0x168/0x250 lib/debugobjects.c:481 Code: dd 80 b9 e6 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 80 b9 e6 87 48 c7 c7 e0 ae e6 87 e8 80 84 ff fd <0f> 0b 83 05 e3 ee 80 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3 RSP: 0018:ffff888095997a28 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815cb526 RDI: ffffed1012b32f37 RBP: ffff888095997a68 R08: ffff8880a92ac580 R09: ffffed1015d04101 R10: ffffed1015d04100 R11: ffff8880ae820807 R12: 0000000000000001 R13: ffffffff88fb5340 R14: ffffffff81627110 R15: ffff8880aa41eab8 __debug_check_no_obj_freed lib/debugobjects.c:963 [inline] debug_check_no_obj_freed+0x2d4/0x43f lib/debugobjects.c:994 kfree+0xf8/0x2c0 mm/slab.c:3755 kvfree+0x61/0x70 mm/util.c:593 netdev_freemem net/core/dev.c:9384 [inline] free_netdev+0x39d/0x450 net/core/dev.c:9533 tun_set_iff drivers/net/tun.c:2871 [inline] __tun_chr_ioctl+0x317b/0x3f30 drivers/net/tun.c:3075 tun_chr_ioctl+0x2b/0x40 drivers/net/tun.c:3355 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:539 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726 ksys_ioctl+0xab/0xd0 fs/ioctl.c:743 __do_sys_ioctl fs/ioctl.c:750 [inline] __se_sys_ioctl fs/ioctl.c:748 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441439 Code: e8 9c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff61c37438 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441439 RDX: 0000000020000400 RSI: 00000000400454ca RDI: 0000000000000004 RBP: 00007fff61c37470 R08: 0000000000000001 R09: 0000000100000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jiri Pirko <jiri@mellanox.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-07 19:21:05 +00:00
goto err_free_dev;
tun: handle register_netdevice() failures properly syzkaller reported a double free [1], caused by the fact that tun driver was not updated properly when priv_destructor was added. When/if register_netdevice() fails, priv_destructor() must have been called already. [1] BUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023 CPU: 0 PID: 2919 Comm: syzkaller227220 Not tainted 4.13.0-rc4+ #23 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x7f/0x260 mm/kasan/report.c:252 kasan_report_double_free+0x55/0x80 mm/kasan/report.c:333 kasan_slab_free+0xa0/0xc0 mm/kasan/kasan.c:514 __cache_free mm/slab.c:3503 [inline] kfree+0xd3/0x260 mm/slab.c:3820 selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023 security_tun_dev_free_security+0x48/0x80 security/security.c:1512 tun_set_iff drivers/net/tun.c:1884 [inline] __tun_chr_ioctl+0x2ce6/0x3d50 drivers/net/tun.c:2064 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x443ff9 RSP: 002b:00007ffc34271f68 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443ff9 RDX: 0000000020533000 RSI: 00000000400454ca RDI: 0000000000000003 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401ce0 R13: 0000000000401d70 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 2919: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x101/0x6f0 mm/slab.c:3627 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:666 [inline] selinux_tun_dev_alloc_security+0x49/0x170 security/selinux/hooks.c:5012 security_tun_dev_alloc_security+0x6d/0xa0 security/security.c:1506 tun_set_iff drivers/net/tun.c:1839 [inline] __tun_chr_ioctl+0x1730/0x3d50 drivers/net/tun.c:2064 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 2919: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x6e/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kfree+0xd3/0x260 mm/slab.c:3820 selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023 security_tun_dev_free_security+0x48/0x80 security/security.c:1512 tun_free_netdev+0x13b/0x1b0 drivers/net/tun.c:1563 register_netdevice+0x8d0/0xee0 net/core/dev.c:7605 tun_set_iff drivers/net/tun.c:1859 [inline] __tun_chr_ioctl+0x1caf/0x3d50 drivers/net/tun.c:2064 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe The buggy address belongs to the object at ffff8801d2843b40 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8801d2843b40, ffff8801d2843b60) The buggy address belongs to the page: page:ffffea000660cea8 count:1 mapcount:0 mapping:ffff8801d2843000 index:0xffff8801d2843fc1 flags: 0x200000000000100(slab) raw: 0200000000000100 ffff8801d2843000 ffff8801d2843fc1 000000010000003f raw: ffffea0006626a40 ffffea00066141a0 ffff8801dbc00100 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d2843a00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d2843a80: 00 00 00 fc fc fc fc fc fb fb fb fb fc fc fc fc >ffff8801d2843b00: 00 00 00 00 fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff8801d2843b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d2843c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ================================================================== Fixes: cf124db566e6 ("net: Fix inconsistent teardown and release of private netdev state.") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-18 20:39:56 +00:00
err_free_flow:
tun_flow_uninit(tun);
security_tun_dev_free_security(tun->security);
err_free_stat:
free_percpu(dev->tstats);
err_free_dev:
free_netdev(dev);
return err;
}
static void tun_get_iff(struct tun_struct *tun, struct ifreq *ifr)
{
strcpy(ifr->ifr_name, tun->dev->name);
ifr->ifr_flags = tun_flags(tun);
}
/* This is like a cut-down ethtool ops, except done via tun fd so no
* privs required. */
static int set_offload(struct tun_struct *tun, unsigned long arg)
{
netdev_features_t features = 0;
if (arg & TUN_F_CSUM) {
features |= NETIF_F_HW_CSUM;
arg &= ~TUN_F_CSUM;
if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
if (arg & TUN_F_TSO_ECN) {
features |= NETIF_F_TSO_ECN;
arg &= ~TUN_F_TSO_ECN;
}
if (arg & TUN_F_TSO4)
features |= NETIF_F_TSO;
if (arg & TUN_F_TSO6)
features |= NETIF_F_TSO6;
arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
}
net: accept UFO datagrams from tuntap and packet Tuntap and similar devices can inject GSO packets. Accept type VIRTIO_NET_HDR_GSO_UDP, even though not generating UFO natively. Processes are expected to use feature negotiation such as TUNSETOFFLOAD to detect supported offload types and refrain from injecting other packets. This process breaks down with live migration: guest kernels do not renegotiate flags, so destination hosts need to expose all features that the source host does. Partially revert the UFO removal from 182e0b6b5846~1..d9d30adf5677. This patch introduces nearly(*) no new code to simplify verification. It brings back verbatim tuntap UFO negotiation, VIRTIO_NET_HDR_GSO_UDP insertion and software UFO segmentation. It does not reinstate protocol stack support, hardware offload (NETIF_F_UFO), SKB_GSO_UDP tunneling in SKB_GSO_SOFTWARE or reception of VIRTIO_NET_HDR_GSO_UDP packets in tuntap. To support SKB_GSO_UDP reappearing in the stack, also reinstate logic in act_csum and openvswitch. Achieve equivalence with v4.13 HEAD by squashing in commit 939912216fa8 ("net: skb_needs_check() removes CHECKSUM_UNNECESSARY check for tx.") and reverting commit 8d63bee643f1 ("net: avoid skb_warn_bad_offload false positives on UFO"). (*) To avoid having to bring back skb_shinfo(skb)->ip6_frag_id, ipv6_proxy_select_ident is changed to return a __be32 and this is assigned directly to the frag_hdr. Also, SKB_GSO_UDP is inserted at the end of the enum to minimize code churn. Tested Booted a v4.13 guest kernel with QEMU. On a host kernel before this patch `ethtool -k eth0` shows UFO disabled. After the patch, it is enabled, same as on a v4.13 host kernel. A UFO packet sent from the guest appears on the tap device: host: nc -l -p -u 8000 & tcpdump -n -i tap0 guest: dd if=/dev/zero of=payload.txt bs=1 count=2000 nc -u 192.16.1.1 8000 < payload.txt Direct tap to tap transmission of VIRTIO_NET_HDR_GSO_UDP succeeds, packets arriving fragmented: ./with_tap_pair.sh ./tap_send_ufo tap0 tap1 (from https://github.com/wdebruij/kerneltools/tree/master/tests) Changes v1 -> v2 - simplified set_offload change (review comment) - documented test procedure Link: http://lkml.kernel.org/r/<CAF=yD-LuUeDuL9YWPJD9ykOZ0QCjNeznPDr6whqZ9NGMNF12Mw@mail.gmail.com> Fixes: fb652fdfe837 ("macvlan/macvtap: Remove NETIF_F_UFO advertisement.") Reported-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-21 15:22:25 +00:00
arg &= ~TUN_F_UFO;
}
/* This gives the user a way to test for new features in future by
* trying to set them. */
if (arg)
return -EINVAL;
tun->set_features = features;
tun->dev->wanted_features &= ~TUN_USER_FEATURES;
tun->dev->wanted_features |= features;
netdev_update_features(tun->dev);
return 0;
}
static void tun_detach_filter(struct tun_struct *tun, int n)
{
int i;
struct tun_file *tfile;
for (i = 0; i < n; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
lock_sock(tfile->socket.sk);
sk_detach_filter(tfile->socket.sk);
release_sock(tfile->socket.sk);
}
tun->filter_attached = false;
}
static int tun_attach_filter(struct tun_struct *tun)
{
int i, ret = 0;
struct tun_file *tfile;
for (i = 0; i < tun->numqueues; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
lock_sock(tfile->socket.sk);
ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
release_sock(tfile->socket.sk);
if (ret) {
tun_detach_filter(tun, i);
return ret;
}
}
tun->filter_attached = true;
return ret;
}
static void tun_set_sndbuf(struct tun_struct *tun)
{
struct tun_file *tfile;
int i;
for (i = 0; i < tun->numqueues; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
tfile->socket.sk->sk_sndbuf = tun->sndbuf;
}
}
static int tun_set_queue(struct file *file, struct ifreq *ifr)
{
struct tun_file *tfile = file->private_data;
struct tun_struct *tun;
int ret = 0;
rtnl_lock();
if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
tun = tfile->detached;
tun: fix LSM/SELinux labeling of tun/tap devices This patch corrects some problems with LSM/SELinux that were introduced with the multiqueue patchset. The problem stems from the fact that the multiqueue work changed the relationship between the tun device and its associated socket; before the socket persisted for the life of the device, however after the multiqueue changes the socket only persisted for the life of the userspace connection (fd open). For non-persistent devices this is not an issue, but for persistent devices this can cause the tun device to lose its SELinux label. We correct this problem by adding an opaque LSM security blob to the tun device struct which allows us to have the LSM security state, e.g. SELinux labeling information, persist for the lifetime of the tun device. In the process we tweak the LSM hooks to work with this new approach to TUN device/socket labeling and introduce a new LSM hook, security_tun_dev_attach_queue(), to approve requests to attach to a TUN queue via TUNSETQUEUE. The SELinux code has been adjusted to match the new LSM hooks, the other LSMs do not make use of the LSM TUN controls. This patch makes use of the recently added "tun_socket:attach_queue" permission to restrict access to the TUNSETQUEUE operation. On older SELinux policies which do not define the "tun_socket:attach_queue" permission the access control decision for TUNSETQUEUE will be handled according to the SELinux policy's unknown permission setting. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@parisplace.org> Tested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14 07:12:19 +00:00
if (!tun) {
ret = -EINVAL;
tun: fix LSM/SELinux labeling of tun/tap devices This patch corrects some problems with LSM/SELinux that were introduced with the multiqueue patchset. The problem stems from the fact that the multiqueue work changed the relationship between the tun device and its associated socket; before the socket persisted for the life of the device, however after the multiqueue changes the socket only persisted for the life of the userspace connection (fd open). For non-persistent devices this is not an issue, but for persistent devices this can cause the tun device to lose its SELinux label. We correct this problem by adding an opaque LSM security blob to the tun device struct which allows us to have the LSM security state, e.g. SELinux labeling information, persist for the lifetime of the tun device. In the process we tweak the LSM hooks to work with this new approach to TUN device/socket labeling and introduce a new LSM hook, security_tun_dev_attach_queue(), to approve requests to attach to a TUN queue via TUNSETQUEUE. The SELinux code has been adjusted to match the new LSM hooks, the other LSMs do not make use of the LSM TUN controls. This patch makes use of the recently added "tun_socket:attach_queue" permission to restrict access to the TUNSETQUEUE operation. On older SELinux policies which do not define the "tun_socket:attach_queue" permission the access control decision for TUNSETQUEUE will be handled according to the SELinux policy's unknown permission setting. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@parisplace.org> Tested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14 07:12:19 +00:00
goto unlock;
}
ret = security_tun_dev_attach_queue(tun->security);
if (ret < 0)
goto unlock;
tun: napi flags belong to tfile Since tun->flags might be shared by multiple tfile structures, it is better to make sure tun_get_user() is using the flags for the current tfile. Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint of what could happen, but we need something stronger to please syzbot. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4 R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff Modules linked in: RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427 Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4 RSP: 0018:ffff8801c400f410 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325 RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0 RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000 R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358 R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004 FS: 00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28 21:51:49 +00:00
ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI,
tun: fix use-after-free when register netdev failed I got a UAF repport in tun driver when doing fuzzy test: [ 466.269490] ================================================================== [ 466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0 [ 466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699 [ 466.271810] [ 466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427 [ 466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 466.271838] Call Trace: [ 466.271858] dump_stack+0xca/0x13e [ 466.271871] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271890] print_address_description+0x79/0x440 [ 466.271906] ? vprintk_func+0x5e/0xf0 [ 466.271920] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271935] __kasan_report+0x15c/0x1df [ 466.271958] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271976] kasan_report+0xe/0x20 [ 466.271987] tun_chr_read_iter+0x2ca/0x2d0 [ 466.272013] do_iter_readv_writev+0x4b7/0x740 [ 466.272032] ? default_llseek+0x2d0/0x2d0 [ 466.272072] do_iter_read+0x1c5/0x5e0 [ 466.272110] vfs_readv+0x108/0x180 [ 466.299007] ? compat_rw_copy_check_uvector+0x440/0x440 [ 466.299020] ? fsnotify+0x888/0xd50 [ 466.299040] ? __fsnotify_parent+0xd0/0x350 [ 466.299064] ? fsnotify_first_mark+0x1e0/0x1e0 [ 466.304548] ? vfs_write+0x264/0x510 [ 466.304569] ? ksys_write+0x101/0x210 [ 466.304591] ? do_preadv+0x116/0x1a0 [ 466.304609] do_preadv+0x116/0x1a0 [ 466.309829] do_syscall_64+0xc8/0x600 [ 466.309849] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.309861] RIP: 0033:0x4560f9 [ 466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127 [ 466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9 [ 466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003 [ 466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000 [ 466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10 [ 466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000 [ 466.323057] [ 466.323064] Allocated by task 2605: [ 466.335165] save_stack+0x19/0x80 [ 466.336240] __kasan_kmalloc.constprop.8+0xa0/0xd0 [ 466.337755] kmem_cache_alloc+0xe8/0x320 [ 466.339050] getname_flags+0xca/0x560 [ 466.340229] user_path_at_empty+0x2c/0x50 [ 466.341508] vfs_statx+0xe6/0x190 [ 466.342619] __do_sys_newstat+0x81/0x100 [ 466.343908] do_syscall_64+0xc8/0x600 [ 466.345303] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.347034] [ 466.347517] Freed by task 2605: [ 466.348471] save_stack+0x19/0x80 [ 466.349476] __kasan_slab_free+0x12e/0x180 [ 466.350726] kmem_cache_free+0xc8/0x430 [ 466.351874] putname+0xe2/0x120 [ 466.352921] filename_lookup+0x257/0x3e0 [ 466.354319] vfs_statx+0xe6/0x190 [ 466.355498] __do_sys_newstat+0x81/0x100 [ 466.356889] do_syscall_64+0xc8/0x600 [ 466.358037] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.359567] [ 466.360050] The buggy address belongs to the object at ffff888372139100 [ 466.360050] which belongs to the cache names_cache of size 4096 [ 466.363735] The buggy address is located 336 bytes inside of [ 466.363735] 4096-byte region [ffff888372139100, ffff88837213a100) [ 466.367179] The buggy address belongs to the page: [ 466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0 [ 466.371582] flags: 0x2fffff80010200(slab|head) [ 466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00 [ 466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 [ 466.377778] page dumped because: kasan: bad access detected [ 466.379730] [ 466.380288] Memory state around the buggy address: [ 466.381844] ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.384009] ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.388257] ^ [ 466.390234] ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.392512] ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.394667] ================================================================== tun_chr_read_iter() accessed the memory which freed by free_netdev() called by tun_set_iff(): CPUA CPUB tun_set_iff() alloc_netdev_mqs() tun_attach() tun_chr_read_iter() tun_get() tun_do_read() tun_ring_recv() register_netdevice() <-- inject error goto err_detach tun_detach_all() <-- set RCV_SHUTDOWN free_netdev() <-- called from err_free_dev path netdev_freemem() <-- free the memory without check refcount (In this path, the refcount cannot prevent freeing the memory of dev, and the memory will be used by dev_put() called by tun_chr_read_iter() on CPUB.) (Break from tun_ring_recv(), because RCV_SHUTDOWN is set) tun_put() dev_put() <-- use the memory freed by netdev_freemem() Put the publishing of tfile->tun after register_netdevice(), so tun_get() won't get the tun pointer that freed by err_detach path if register_netdevice() failed. Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice") Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-10 10:56:57 +00:00
tun->flags & IFF_NAPI_FRAGS, true);
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
} else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
tun = rtnl_dereference(tfile->tun);
if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
ret = -EINVAL;
else
__tun_detach(tfile, false);
} else
ret = -EINVAL;
if (ret >= 0)
netdev_state_change(tun->dev);
tun: fix LSM/SELinux labeling of tun/tap devices This patch corrects some problems with LSM/SELinux that were introduced with the multiqueue patchset. The problem stems from the fact that the multiqueue work changed the relationship between the tun device and its associated socket; before the socket persisted for the life of the device, however after the multiqueue changes the socket only persisted for the life of the userspace connection (fd open). For non-persistent devices this is not an issue, but for persistent devices this can cause the tun device to lose its SELinux label. We correct this problem by adding an opaque LSM security blob to the tun device struct which allows us to have the LSM security state, e.g. SELinux labeling information, persist for the lifetime of the tun device. In the process we tweak the LSM hooks to work with this new approach to TUN device/socket labeling and introduce a new LSM hook, security_tun_dev_attach_queue(), to approve requests to attach to a TUN queue via TUNSETQUEUE. The SELinux code has been adjusted to match the new LSM hooks, the other LSMs do not make use of the LSM TUN controls. This patch makes use of the recently added "tun_socket:attach_queue" permission to restrict access to the TUNSETQUEUE operation. On older SELinux policies which do not define the "tun_socket:attach_queue" permission the access control decision for TUNSETQUEUE will be handled according to the SELinux policy's unknown permission setting. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@parisplace.org> Tested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14 07:12:19 +00:00
unlock:
rtnl_unlock();
return ret;
}
static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog __rcu **prog_p,
void __user *data)
{
struct bpf_prog *prog;
int fd;
if (copy_from_user(&fd, data, sizeof(fd)))
return -EFAULT;
if (fd == -1) {
prog = NULL;
} else {
prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
if (IS_ERR(prog))
return PTR_ERR(prog);
}
return __tun_set_ebpf(tun, prog_p, prog);
}
static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
unsigned long arg, int ifreq_len)
{
struct tun_file *tfile = file->private_data;
struct net *net = sock_net(&tfile->sk);
struct tun_struct *tun;
void __user* argp = (void __user*)arg;
unsigned int ifindex, carrier;
struct ifreq ifr;
kuid_t owner;
kgid_t group;
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
int sndbuf;
int vnet_hdr_sz;
int le;
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
int ret;
bool do_notify = false;
if (cmd == TUNSETIFF || cmd == TUNSETQUEUE ||
(_IOC_TYPE(cmd) == SOCK_IOC_TYPE && cmd != SIOCGSKNS)) {
if (copy_from_user(&ifr, argp, ifreq_len))
return -EFAULT;
} else {
memset(&ifr, 0, sizeof(ifr));
}
if (cmd == TUNGETFEATURES) {
/* Currently this just means: "what IFF flags are valid?".
* This is needed because we never checked for invalid flags on
* TUNSETIFF.
*/
return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
(unsigned int __user*)argp);
} else if (cmd == TUNSETQUEUE) {
return tun_set_queue(file, &ifr);
} else if (cmd == SIOCGSKNS) {
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
return open_related_ns(&net->ns, get_net_ns);
}
ret = 0;
rtnl_lock();
tun = tun_get(tfile);
if (cmd == TUNSETIFF) {
ret = -EEXIST;
if (tun)
goto unlock;
ifr.ifr_name[IFNAMSIZ-1] = '\0';
ret = tun_set_iff(net, file, &ifr);
if (ret)
goto unlock;
if (copy_to_user(argp, &ifr, ifreq_len))
ret = -EFAULT;
goto unlock;
}
if (cmd == TUNSETIFINDEX) {
ret = -EPERM;
if (tun)
goto unlock;
ret = -EFAULT;
if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
goto unlock;
ret = 0;
tfile->ifindex = ifindex;
goto unlock;
}
ret = -EBADFD;
if (!tun)
goto unlock;
netif_info(tun, drv, tun->dev, "tun_chr_ioctl cmd %u\n", cmd);
net = dev_net(tun->dev);
ret = 0;
switch (cmd) {
case TUNGETIFF:
tun_get_iff(tun, &ifr);
if (tfile->detached)
ifr.ifr_flags |= IFF_DETACH_QUEUE;
if (!tfile->socket.sk->sk_filter)
ifr.ifr_flags |= IFF_NOFILTER;
if (copy_to_user(argp, &ifr, ifreq_len))
ret = -EFAULT;
break;
case TUNSETNOCSUM:
/* Disable/Enable checksum */
/* [unimplemented] */
netif_info(tun, drv, tun->dev, "ignored: set checksum %s\n",
arg ? "disabled" : "enabled");
break;
case TUNSETPERSIST:
/* Disable/Enable persist mode. Keep an extra reference to the
* module to prevent the module being unprobed.
*/
if (arg && !(tun->flags & IFF_PERSIST)) {
tun->flags |= IFF_PERSIST;
__module_get(THIS_MODULE);
do_notify = true;
}
if (!arg && (tun->flags & IFF_PERSIST)) {
tun->flags &= ~IFF_PERSIST;
module_put(THIS_MODULE);
do_notify = true;
}
netif_info(tun, drv, tun->dev, "persist %s\n",
arg ? "enabled" : "disabled");
break;
case TUNSETOWNER:
/* Set owner of the device */
owner = make_kuid(current_user_ns(), arg);
if (!uid_valid(owner)) {
ret = -EINVAL;
break;
}
tun->owner = owner;
do_notify = true;
netif_info(tun, drv, tun->dev, "owner set to %u\n",
from_kuid(&init_user_ns, tun->owner));
break;
case TUNSETGROUP:
/* Set group of the device */
group = make_kgid(current_user_ns(), arg);
if (!gid_valid(group)) {
ret = -EINVAL;
break;
}
tun->group = group;
do_notify = true;
netif_info(tun, drv, tun->dev, "group set to %u\n",
from_kgid(&init_user_ns, tun->group));
break;
case TUNSETLINK:
/* Only allow setting the type when the interface is down */
if (tun->dev->flags & IFF_UP) {
netif_info(tun, drv, tun->dev,
"Linktype set failed because interface is up\n");
ret = -EBUSY;
} else {
tun->dev->type = (int) arg;
netif_info(tun, drv, tun->dev, "linktype set to %d\n",
tun->dev->type);
ret = 0;
}
break;
case TUNSETDEBUG:
tun->msg_enable = (u32)arg;
break;
case TUNSETOFFLOAD:
ret = set_offload(tun, arg);
break;
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
case TUNSETTXFILTER:
/* Can be set only for TAPs */
ret = -EINVAL;
if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
break;
ret = update_filter(&tun->txflt, (void __user *)arg);
break;
case SIOCGIFHWADDR:
/* Get hw address */
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
ifr.ifr_hwaddr.sa_family = tun->dev->type;
if (copy_to_user(argp, &ifr, ifreq_len))
ret = -EFAULT;
break;
case SIOCSIFHWADDR:
tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 05:18:19 +00:00
/* Set hw address */
ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr, NULL);
break;
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
case TUNGETSNDBUF:
sndbuf = tfile->socket.sk->sk_sndbuf;
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
ret = -EFAULT;
break;
case TUNSETSNDBUF:
if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
ret = -EFAULT;
break;
}
tun/tap: sanitize TUNSETSNDBUF input Syzkaller found several variants of the lockup below by setting negative values with the TUNSETSNDBUF ioctl. This patch adds a sanity check to both the tun and tap versions of this ioctl. watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [repro:2389] Modules linked in: irq event stamp: 329692056 hardirqs last enabled at (329692055): [<ffffffff824b8381>] _raw_spin_unlock_irqrestore+0x31/0x75 hardirqs last disabled at (329692056): [<ffffffff824b9e58>] apic_timer_interrupt+0x98/0xb0 softirqs last enabled at (35659740): [<ffffffff824bc958>] __do_softirq+0x328/0x48c softirqs last disabled at (35659731): [<ffffffff811c796c>] irq_exit+0xbc/0xd0 CPU: 0 PID: 2389 Comm: repro Not tainted 4.14.0-rc7 #23 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff880009452140 task.stack: ffff880006a20000 RIP: 0010:_raw_spin_lock_irqsave+0x11/0x80 RSP: 0018:ffff880006a27c50 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: ffff880009ac68d0 RBX: ffff880006a27ce0 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffff880006a27ce0 RDI: ffff880009ac6900 RBP: ffff880006a27c60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 000000000063ff00 R12: ffff880009ac6900 R13: ffff880006a27cf8 R14: 0000000000000001 R15: ffff880006a27cf8 FS: 00007f4be4838700(0000) GS:ffff88000cc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020101000 CR3: 0000000009616000 CR4: 00000000000006f0 Call Trace: prepare_to_wait+0x26/0xc0 sock_alloc_send_pskb+0x14e/0x270 ? remove_wait_queue+0x60/0x60 tun_get_user+0x2cc/0x19d0 ? __tun_get+0x60/0x1b0 tun_chr_write_iter+0x57/0x86 __vfs_write+0x156/0x1e0 vfs_write+0xf7/0x230 SyS_write+0x57/0xd0 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7f4be4356df9 RSP: 002b:00007ffc18101c08 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4be4356df9 RDX: 0000000000000046 RSI: 0000000020101000 RDI: 0000000000000005 RBP: 00007ffc18101c40 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000293 R12: 0000559c75f64780 R13: 00007ffc18101d30 R14: 0000000000000000 R15: 0000000000000000 Fixes: 33dccbb050bb ("tun: Limit amount of queued packets per device") Fixes: 20d29d7a916a ("net: macvtap driver") Signed-off-by: Craig Gallek <kraig@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-30 22:50:11 +00:00
if (sndbuf <= 0) {
ret = -EINVAL;
break;
}
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
tun->sndbuf = sndbuf;
tun_set_sndbuf(tun);
tun: Limit amount of queued packets per device Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06 05:25:32 +00:00
break;
case TUNGETVNETHDRSZ:
vnet_hdr_sz = tun->vnet_hdr_sz;
if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
ret = -EFAULT;
break;
case TUNSETVNETHDRSZ:
if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
ret = -EFAULT;
break;
}
if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
ret = -EINVAL;
break;
}
tun->vnet_hdr_sz = vnet_hdr_sz;
break;
case TUNGETVNETLE:
le = !!(tun->flags & TUN_VNET_LE);
if (put_user(le, (int __user *)argp))
ret = -EFAULT;
break;
case TUNSETVNETLE:
if (get_user(le, (int __user *)argp)) {
ret = -EFAULT;
break;
}
if (le)
tun->flags |= TUN_VNET_LE;
else
tun->flags &= ~TUN_VNET_LE;
break;
case TUNGETVNETBE:
ret = tun_get_vnet_be(tun, argp);
break;
case TUNSETVNETBE:
ret = tun_set_vnet_be(tun, argp);
break;
case TUNATTACHFILTER:
/* Can be set only for TAPs */
ret = -EINVAL;
if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
break;
ret = -EFAULT;
if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
break;
ret = tun_attach_filter(tun);
break;
case TUNDETACHFILTER:
/* Can be set only for TAPs */
ret = -EINVAL;
if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
break;
ret = 0;
tun_detach_filter(tun, tun->numqueues);
break;
case TUNGETFILTER:
ret = -EINVAL;
if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
break;
ret = -EFAULT;
if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
break;
ret = 0;
break;
case TUNSETSTEERINGEBPF:
ret = tun_set_ebpf(tun, &tun->steering_prog, argp);
break;
case TUNSETFILTEREBPF:
ret = tun_set_ebpf(tun, &tun->filter_prog, argp);
break;
case TUNSETCARRIER:
ret = -EFAULT;
if (copy_from_user(&carrier, argp, sizeof(carrier)))
goto unlock;
ret = tun_net_change_carrier(tun->dev, (bool)carrier);
break;
case TUNGETDEVNETNS:
ret = -EPERM;
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
goto unlock;
ret = open_related_ns(&net->ns, get_net_ns);
break;
default:
ret = -EINVAL;
break;
}
if (do_notify)
netdev_state_change(tun->dev);
unlock:
rtnl_unlock();
if (tun)
tun_put(tun);
return ret;
}
static long tun_chr_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
}
#ifdef CONFIG_COMPAT
static long tun_chr_compat_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case TUNSETIFF:
case TUNGETIFF:
case TUNSETTXFILTER:
case TUNGETSNDBUF:
case TUNSETSNDBUF:
case SIOCGIFHWADDR:
case SIOCSIFHWADDR:
arg = (unsigned long)compat_ptr(arg);
break;
default:
arg = (compat_ulong_t)arg;
break;
}
/*
* compat_ifreq is shorter than ifreq, so we must not access beyond
* the end of that structure. All fields that are used in this
* driver are compatible though, we don't need to convert the
* contents.
*/
return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
}
#endif /* CONFIG_COMPAT */
static int tun_chr_fasync(int fd, struct file *file, int on)
{
struct tun_file *tfile = file->private_data;
int ret;
if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
goto out;
if (on) {
__f_setown(file, task_pid(current), PIDTYPE_TGID, 0);
tfile->flags |= TUN_FASYNC;
} else
tfile->flags &= ~TUN_FASYNC;
ret = 0;
out:
return ret;
}
static int tun_chr_open(struct inode *inode, struct file * file)
{
struct net *net = current->nsproxy->net_ns;
struct tun_file *tfile;
tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
&tun_proto, 0);
if (!tfile)
return -ENOMEM;
if (ptr_ring_init(&tfile->tx_ring, 0, GFP_KERNEL)) {
sk_free(&tfile->sk);
return -ENOMEM;
}
mutex_init(&tfile->napi_mutex);
RCU_INIT_POINTER(tfile->tun, NULL);
tfile->flags = 0;
tfile->ifindex = 0;
init_waitqueue_head(&tfile->socket.wq.wait);
tfile->socket.file = file;
tfile->socket.ops = &tun_socket_ops;
sock_init_data(&tfile->socket, &tfile->sk);
tfile->sk.sk_write_space = tun_sock_write_space;
tfile->sk.sk_sndbuf = INT_MAX;
file->private_data = tfile;
tuntap: fix ambigious multiqueue API The current multiqueue API is ambigious which may confuse both user and LSM to do things correctly: - Both TUNSETIFF and TUNSETQUEUE could be used to create the queues of a tuntap device. - TUNSETQUEUE were used to disable and enable a specific queue of the device. But since the state of tuntap were completely removed from the queue, it could be used to attach to another device (there's no such kind of requirement currently, and it needs new kind of LSM policy. - TUNSETQUEUE could be used to attach to a persistent device without any queues. This kind of attching bypass the necessary checking during TUNSETIFF and may lead unexpected result. So this patch tries to make a cleaner and simpler API by: - Only allow TUNSETIFF to create queues. - TUNSETQUEUE could be only used to disable and enabled the queues of a device, and the state of the tuntap device were not detachd from the queues when it was disabled, so TUNSETQUEUE could be only used after TUNSETIFF and with the same device. This is done by introducing a list which keeps track of all queues which were disabled. The queue would be moved between this list and tfiles[] array when it was enabled/disabled. A pointer of the tun_struct were also introdued to track the device it belongs to when it was disabled. After the change, the isolation between management and application could be done through: TUNSETIFF were only called by management software and TUNSETQUEUE were only called by application.For LSM/SELinux, the things left is to do proper check during tun_set_queue() if needed. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 23:53:30 +00:00
INIT_LIST_HEAD(&tfile->next);
sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
return 0;
}
static int tun_chr_close(struct inode *inode, struct file *file)
{
struct tun_file *tfile = file->private_data;
tun_detach(tfile, true);
return 0;
}
#ifdef CONFIG_PROC_FS
static void tun_chr_show_fdinfo(struct seq_file *m, struct file *file)
{
struct tun_file *tfile = file->private_data;
struct tun_struct *tun;
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
rtnl_lock();
tun = tun_get(tfile);
if (tun)
tun_get_iff(tun, &ifr);
rtnl_unlock();
if (tun)
tun_put(tun);
seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
}
#endif
static const struct file_operations tun_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read_iter = tun_chr_read_iter,
.write_iter = tun_chr_write_iter,
.poll = tun_chr_poll,
.unlocked_ioctl = tun_chr_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = tun_chr_compat_ioctl,
#endif
.open = tun_chr_open,
.release = tun_chr_close,
.fasync = tun_chr_fasync,
#ifdef CONFIG_PROC_FS
.show_fdinfo = tun_chr_show_fdinfo,
#endif
};
static struct miscdevice tun_miscdev = {
.minor = TUN_MINOR,
.name = "tun",
.nodename = "net/tun",
.fops = &tun_fops,
};
/* ethtool interface */
static void tun_default_link_ksettings(struct net_device *dev,
struct ethtool_link_ksettings *cmd)
{
ethtool_link_ksettings_zero_link_mode(cmd, supported);
ethtool_link_ksettings_zero_link_mode(cmd, advertising);
cmd->base.speed = SPEED_10;
cmd->base.duplex = DUPLEX_FULL;
cmd->base.port = PORT_TP;
cmd->base.phy_address = 0;
cmd->base.autoneg = AUTONEG_DISABLE;
}
static int tun_get_link_ksettings(struct net_device *dev,
struct ethtool_link_ksettings *cmd)
{
struct tun_struct *tun = netdev_priv(dev);
memcpy(cmd, &tun->link_ksettings, sizeof(*cmd));
return 0;
}
static int tun_set_link_ksettings(struct net_device *dev,
const struct ethtool_link_ksettings *cmd)
{
struct tun_struct *tun = netdev_priv(dev);
memcpy(&tun->link_ksettings, cmd, sizeof(*cmd));
return 0;
}
static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
struct tun_struct *tun = netdev_priv(dev);
strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
strlcpy(info->version, DRV_VERSION, sizeof(info->version));
switch (tun->flags & TUN_TYPE_MASK) {
case IFF_TUN:
strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
break;
case IFF_TAP:
strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
break;
}
}
static u32 tun_get_msglevel(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
return tun->msg_enable;
}
static void tun_set_msglevel(struct net_device *dev, u32 value)
{
struct tun_struct *tun = netdev_priv(dev);
tun->msg_enable = value;
}
static int tun_get_coalesce(struct net_device *dev,
struct ethtool_coalesce *ec)
{
struct tun_struct *tun = netdev_priv(dev);
ec->rx_max_coalesced_frames = tun->rx_batched;
return 0;
}
static int tun_set_coalesce(struct net_device *dev,
struct ethtool_coalesce *ec)
{
struct tun_struct *tun = netdev_priv(dev);
if (ec->rx_max_coalesced_frames > NAPI_POLL_WEIGHT)
tun->rx_batched = NAPI_POLL_WEIGHT;
else
tun->rx_batched = ec->rx_max_coalesced_frames;
return 0;
}
static const struct ethtool_ops tun_ethtool_ops = {
.supported_coalesce_params = ETHTOOL_COALESCE_RX_MAX_FRAMES,
.get_drvinfo = tun_get_drvinfo,
.get_msglevel = tun_get_msglevel,
.set_msglevel = tun_set_msglevel,
.get_link = ethtool_op_get_link,
.get_ts_info = ethtool_op_get_ts_info,
.get_coalesce = tun_get_coalesce,
.set_coalesce = tun_set_coalesce,
.get_link_ksettings = tun_get_link_ksettings,
.set_link_ksettings = tun_set_link_ksettings,
};
static int tun_queue_resize(struct tun_struct *tun)
{
struct net_device *dev = tun->dev;
struct tun_file *tfile;
struct ptr_ring **rings;
int n = tun->numqueues + tun->numdisabled;
int ret, i;
rings = kmalloc_array(n, sizeof(*rings), GFP_KERNEL);
if (!rings)
return -ENOMEM;
for (i = 0; i < tun->numqueues; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
rings[i] = &tfile->tx_ring;
}
list_for_each_entry(tfile, &tun->disabled, next)
rings[i++] = &tfile->tx_ring;
ret = ptr_ring_resize_multiple(rings, n,
dev->tx_queue_len, GFP_KERNEL,
tun_ptr_free);
kfree(rings);
return ret;
}
static int tun_device_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct tun_struct *tun = netdev_priv(dev);
int i;
tun: Don't assume type tun in tun_device_event The referenced change added a netlink notifier for processing device queue size events. These events are fired for all devices but the registered callback assumed they only occurred for tun devices. This fix adds a check (borrowed from macvtap.c) to discard non-tun device events. For reference, this fixes the following splat: [ 71.505935] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 71.513870] IP: [<ffffffff8153c1a0>] tun_device_event+0x110/0x340 [ 71.519906] PGD 3f41f56067 PUD 3f264b7067 PMD 0 [ 71.524497] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC [ 71.529374] gsmi: Log Shutdown Reason 0x03 [ 71.533417] Modules linked in:[ 71.533826] mlx4_en: eth1: Link Up [ 71.539616] bonding w1_therm wire cdc_acm ehci_pci ehci_hcd mlx4_en ib_uverbs mlx4_ib ib_core mlx4_core [ 71.549282] CPU: 12 PID: 7915 Comm: set.ixion-haswe Not tainted 4.7.0-dbx-DEV #8 [ 71.556586] Hardware name: Intel Grantley,Wellsburg/Ixion_IT_15, BIOS 2.58.0 05/03/2016 [ 71.564495] task: ffff887f00bb20c0 ti: ffff887f00798000 task.ti: ffff887f00798000 [ 71.571894] RIP: 0010:[<ffffffff8153c1a0>] [<ffffffff8153c1a0>] tun_device_event+0x110/0x340 [ 71.580327] RSP: 0018:ffff887f0079bbd8 EFLAGS: 00010202 [ 71.585576] RAX: fffffffffffffae8 RBX: ffff887ef6d03378 RCX: 0000000000000000 [ 71.592624] RDX: 0000000000000000 RSI: 0000000000000028 RDI: 0000000000000000 [ 71.599675] RBP: ffff887f0079bc48 R08: 0000000000000000 R09: 0000000000000001 [ 71.606730] R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000010 [ 71.613780] R13: 0000000000000000 R14: 0000000000000001 R15: ffff887f0079bd00 [ 71.620832] FS: 00007f5cdc581700(0000) GS:ffff883f7f700000(0000) knlGS:0000000000000000 [ 71.628826] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 71.634500] CR2: 0000000000000010 CR3: 0000003f3eb62000 CR4: 00000000001406e0 [ 71.641549] Stack: [ 71.643533] ffff887f0079bc08 0000000000000246 000000000000001e ffff887ef6d00000 [ 71.650871] ffff887f0079bd00 0000000000000000 0000000000000000 ffffffff00000000 [ 71.658210] ffff887f0079bc48 ffffffff81d24070 00000000fffffff9 ffffffff81cec7a0 [ 71.665549] Call Trace: [ 71.667975] [<ffffffff810eeb0d>] notifier_call_chain+0x5d/0x80 [ 71.673823] [<ffffffff816365d0>] ? show_tx_maxrate+0x30/0x30 [ 71.679502] [<ffffffff810eeb3e>] __raw_notifier_call_chain+0xe/0x10 [ 71.685778] [<ffffffff810eeb56>] raw_notifier_call_chain+0x16/0x20 [ 71.691976] [<ffffffff8160eb30>] call_netdevice_notifiers_info+0x40/0x70 [ 71.698681] [<ffffffff8160ec36>] call_netdevice_notifiers+0x16/0x20 [ 71.704956] [<ffffffff81636636>] change_tx_queue_len+0x66/0x90 [ 71.710807] [<ffffffff816381ef>] netdev_store.isra.5+0xbf/0xd0 [ 71.716658] [<ffffffff81638350>] tx_queue_len_store+0x50/0x60 [ 71.722431] [<ffffffff814a6798>] dev_attr_store+0x18/0x30 [ 71.727857] [<ffffffff812ea3ff>] sysfs_kf_write+0x4f/0x70 [ 71.733274] [<ffffffff812e9507>] kernfs_fop_write+0x147/0x1d0 [ 71.739045] [<ffffffff81134a4f>] ? rcu_read_lock_sched_held+0x8f/0xa0 [ 71.745499] [<ffffffff8125a108>] __vfs_write+0x28/0x120 [ 71.750748] [<ffffffff8111b137>] ? percpu_down_read+0x57/0x90 [ 71.756516] [<ffffffff8125d7d8>] ? __sb_start_write+0xc8/0xe0 [ 71.762278] [<ffffffff8125d7d8>] ? __sb_start_write+0xc8/0xe0 [ 71.768038] [<ffffffff8125bd5e>] vfs_write+0xbe/0x1b0 [ 71.773113] [<ffffffff8125c092>] SyS_write+0x52/0xa0 [ 71.778110] [<ffffffff817528e5>] entry_SYSCALL_64_fastpath+0x18/0xa8 [ 71.784472] Code: 45 31 f6 48 8b 93 78 33 00 00 48 81 c3 78 33 00 00 48 39 d3 48 8d 82 e8 fa ff ff 74 25 48 8d b0 40 05 00 00 49 63 d6 41 83 c6 01 <49> 89 34 d4 48 8b 90 18 05 00 00 48 39 d3 48 8d 82 e8 fa ff ff [ 71.803655] RIP [<ffffffff8153c1a0>] tun_device_event+0x110/0x340 [ 71.809769] RSP <ffff887f0079bbd8> [ 71.813213] CR2: 0000000000000010 [ 71.816512] ---[ end trace 4db6449606319f73 ]--- Fixes: 1576d9860599 ("tun: switch to use skb array for tx") Signed-off-by: Craig Gallek <kraig@google.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-06 22:44:20 +00:00
if (dev->rtnl_link_ops != &tun_link_ops)
return NOTIFY_DONE;
switch (event) {
case NETDEV_CHANGE_TX_QUEUE_LEN:
if (tun_queue_resize(tun))
return NOTIFY_BAD;
break;
case NETDEV_UP:
for (i = 0; i < tun->numqueues; i++) {
struct tun_file *tfile;
tfile = rtnl_dereference(tun->tfiles[i]);
tfile->socket.sk->sk_write_space(tfile->socket.sk);
}
break;
default:
break;
}
return NOTIFY_DONE;
}
static struct notifier_block tun_notifier_block __read_mostly = {
.notifier_call = tun_device_event,
};
static int __init tun_init(void)
{
int ret = 0;
pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
ret = rtnl_link_register(&tun_link_ops);
if (ret) {
pr_err("Can't register link_ops\n");
goto err_linkops;
}
ret = misc_register(&tun_miscdev);
if (ret) {
pr_err("Can't register misc device %d\n", TUN_MINOR);
goto err_misc;
}
ret = register_netdevice_notifier(&tun_notifier_block);
if (ret) {
pr_err("Can't register netdevice notifier\n");
goto err_notifier;
}
return 0;
err_notifier:
misc_deregister(&tun_miscdev);
err_misc:
rtnl_link_unregister(&tun_link_ops);
err_linkops:
return ret;
}
static void tun_cleanup(void)
{
misc_deregister(&tun_miscdev);
rtnl_link_unregister(&tun_link_ops);
unregister_netdevice_notifier(&tun_notifier_block);
}
/* Get an underlying socket object from tun file. Returns error unless file is
* attached to a device. The returned object works like a packet socket, it
* can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
* holding a reference to the file for as long as the socket is in use. */
struct socket *tun_get_socket(struct file *file)
{
struct tun_file *tfile;
if (file->f_op != &tun_fops)
return ERR_PTR(-EINVAL);
tfile = file->private_data;
if (!tfile)
return ERR_PTR(-EBADFD);
return &tfile->socket;
}
EXPORT_SYMBOL_GPL(tun_get_socket);
struct ptr_ring *tun_get_tx_ring(struct file *file)
{
struct tun_file *tfile;
if (file->f_op != &tun_fops)
return ERR_PTR(-EINVAL);
tfile = file->private_data;
if (!tfile)
return ERR_PTR(-EBADFD);
return &tfile->tx_ring;
}
EXPORT_SYMBOL_GPL(tun_get_tx_ring);
module_init(tun_init);
module_exit(tun_cleanup);
MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_AUTHOR(DRV_COPYRIGHT);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(TUN_MINOR);
driver core: add devname module aliases to allow module on-demand auto-loading This adds: alias: devname:<name> to some common kernel modules, which will allow the on-demand loading of the kernel module when the device node is accessed. Ideally all these modules would be compiled-in, but distros seems too much in love with their modularization that we need to cover the common cases with this new facility. It will allow us to remove a bunch of pretty useless init scripts and modprobes from init scripts. The static device node aliases will be carried in the module itself. The program depmod will extract this information to a file in the module directory: $ cat /lib/modules/2.6.34-00650-g537b60d-dirty/modules.devname # Device nodes to trigger on-demand module loading. microcode cpu/microcode c10:184 fuse fuse c10:229 ppp_generic ppp c108:0 tun net/tun c10:200 dm_mod mapper/control c10:235 Udev will pick up the depmod created file on startup and create all the static device nodes which the kernel modules specify, so that these modules get automatically loaded when the device node is accessed: $ /sbin/udevd --debug ... static_dev_create_from_modules: mknod '/dev/cpu/microcode' c10:184 static_dev_create_from_modules: mknod '/dev/fuse' c10:229 static_dev_create_from_modules: mknod '/dev/ppp' c108:0 static_dev_create_from_modules: mknod '/dev/net/tun' c10:200 static_dev_create_from_modules: mknod '/dev/mapper/control' c10:235 udev_rules_apply_static_dev_perms: chmod '/dev/net/tun' 0666 udev_rules_apply_static_dev_perms: chmod '/dev/fuse' 0666 A few device nodes are switched to statically allocated numbers, to allow the static nodes to work. This might also useful for systems which still run a plain static /dev, which is completely unsafe to use with any dynamic minor numbers. Note: The devname aliases must be limited to the *common* and *single*instance* device nodes, like the misc devices, and never be used for conceptually limited systems like the loop devices, which should rather get fixed properly and get a control node for losetup to talk to, instead of creating a random number of device nodes in advance, regardless if they are ever used. This facility is to hide the mess distros are creating with too modualized kernels, and just to hide that these modules are not compiled-in, and not to paper-over broken concepts. Thanks! :) Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: David S. Miller <davem@davemloft.net> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Chris Mason <chris.mason@oracle.com> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Cc: Ian Kent <raven@themaw.net> Signed-Off-By: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 16:07:20 +00:00
MODULE_ALIAS("devname:net/tun");