linux/net
Eric Dumazet dacab578c7 vlan: fix a potential uninit-value in vlan_dev_hard_start_xmit()
syzbot triggered the following splat [1], sending an empty message
through pppoe_sendmsg().

When VLAN_FLAG_REORDER_HDR flag is set, vlan_dev_hard_header()
does not push extra bytes for the VLAN header, because vlan is offloaded.

Unfortunately vlan_dev_hard_start_xmit() first reads veth->h_vlan_proto
before testing (vlan->flags & VLAN_FLAG_REORDER_HDR).

We need to swap the two conditions.

[1]
BUG: KMSAN: uninit-value in vlan_dev_hard_start_xmit+0x171/0x7f0 net/8021q/vlan_dev.c:111
vlan_dev_hard_start_xmit+0x171/0x7f0 net/8021q/vlan_dev.c:111
__netdev_start_xmit include/linux/netdevice.h:4883 [inline]
netdev_start_xmit include/linux/netdevice.h:4897 [inline]
xmit_one net/core/dev.c:3580 [inline]
dev_hard_start_xmit+0x253/0xa20 net/core/dev.c:3596
__dev_queue_xmit+0x3c7f/0x5ac0 net/core/dev.c:4246
dev_queue_xmit include/linux/netdevice.h:3053 [inline]
pppoe_sendmsg+0xa93/0xb80 drivers/net/ppp/pppoe.c:900
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0xa24/0xe40 net/socket.c:2501
___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555
__sys_sendmmsg+0x411/0xa50 net/socket.c:2641
__do_sys_sendmmsg net/socket.c:2670 [inline]
__se_sys_sendmmsg net/socket.c:2667 [inline]
__x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2667
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was created at:
slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:774
slab_alloc_node mm/slub.c:3452 [inline]
kmem_cache_alloc_node+0x543/0xab0 mm/slub.c:3497
kmalloc_reserve+0x148/0x470 net/core/skbuff.c:520
__alloc_skb+0x3a7/0x850 net/core/skbuff.c:606
alloc_skb include/linux/skbuff.h:1277 [inline]
sock_wmalloc+0xfe/0x1a0 net/core/sock.c:2583
pppoe_sendmsg+0x3af/0xb80 drivers/net/ppp/pppoe.c:867
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0xa24/0xe40 net/socket.c:2501
___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555
__sys_sendmmsg+0x411/0xa50 net/socket.c:2641
__do_sys_sendmmsg net/socket.c:2670 [inline]
__se_sys_sendmmsg net/socket.c:2667 [inline]
__x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2667
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

CPU: 0 PID: 29770 Comm: syz-executor.0 Not tainted 6.3.0-rc6-syzkaller-gc478e5b17829 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-17 12:55:39 +01:00
..
6lowpan 6lowpan: Remove redundant initialisation. 2023-03-29 08:22:52 +01:00
9p Including fixes from netfilter. 2023-05-05 19:12:01 -07:00
802
8021q vlan: fix a potential uninit-value in vlan_dev_hard_start_xmit() 2023-05-17 12:55:39 +01:00
appletalk
atm Networking changes for 6.4. 2023-04-26 16:07:23 -07:00
ax25
batman-adv net: vlan: introduce skb_vlan_eth_hdr() 2023-04-23 14:16:44 +01:00
bluetooth Driver core changes for 6.4-rc1 2023-04-27 11:53:57 -07:00
bpf bpf: add test_run support for netfilter program type 2023-04-21 11:34:50 -07:00
bpfilter
bridge net: add vlan_get_protocol_and_depth() helper 2023-05-10 10:25:55 +01:00
caif net: caif: Fix use-after-free in cfusbl_device_notify() 2023-03-02 22:22:07 -08:00
can can: j1939: recvmsg(): allow MSG_CMSG_COMPAT flag 2023-05-15 22:24:46 +02:00
ceph Networking changes for 6.3. 2023-02-21 18:24:12 -08:00
core net: datagram: fix data-races in datagram_poll() 2023-05-10 19:06:49 -07:00
dcb
dccp netfilter: keep conntrack reference until IPsecv6 policy checks are done 2023-03-22 21:50:23 +01:00
devlink devlink: Fix crash with CONFIG_NET_NS=n 2023-05-16 19:57:52 -07:00
dns_resolver
dsa net: dsa: tag_ocelot: call only the relevant portion of __skb_vlan_pop() on TX 2023-04-23 14:16:45 +01:00
ethernet
ethtool ethtool: Fix uninitialized number of lanes 2023-05-03 09:13:20 +01:00
handshake net/handshake: Fix section mismatch in handshake_exit 2023-04-21 20:24:57 -07:00
hsr hsr: ratelimit only when errors are printed 2023-03-16 21:11:03 -07:00
ieee802154 net: ieee802154: remove an unnecessary null pointer check 2023-03-17 09:13:53 +01:00
ife
ipv4 tcp: fix possible sk_priority leak in tcp_v4_send_reset() 2023-05-12 10:05:50 +01:00
ipv6 erspan: get the proto with the md version for collect_md 2023-05-13 16:58:58 +01:00
iucv net/iucv: Fix size of interrupt data 2023-03-16 17:34:40 -07:00
kcm
key af_key: Reject optional tunnel/BEET mode templates in outbound policies 2023-05-10 07:04:51 +02:00
l2tp l2tp: generate correct module alias strings 2023-03-31 09:25:12 +01:00
l3mdev
lapb
llc net: deal with most data-races in sk_wait_event() 2023-05-10 10:03:32 +01:00
mac80211 wireless-next patches for v6.4 2023-04-21 07:35:51 -07:00
mac802154 mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep() 2023-04-05 13:48:04 +00:00
mctp mctp: remove MODULE_LICENSE in non-modules 2023-03-09 23:06:21 -08:00
mpls
mptcp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-04-20 16:29:51 -07:00
ncsi net/ncsi: clear Tx enable mode when handling a Config required AEN 2023-04-28 09:35:33 +01:00
netfilter netfilter: conntrack: fix possible bug_on with enable_hooks=1 2023-05-10 08:50:39 +02:00
netlabel
netlink netlink: annotate accesses to nlk->cb_running 2023-05-10 09:28:38 +01:00
netrom
nfc nfc: change order inside nfc_se_io error path 2023-03-07 13:37:05 -08:00
nsh net: nsh: Use correct mac_offset to unwind gso skb in nsh_gso_segment() 2023-05-15 08:40:27 +01:00
openvswitch net: openvswitch: fix race on port output 2023-04-07 19:42:53 -07:00
packet net: add vlan_get_protocol_and_depth() helper 2023-05-10 10:25:55 +01:00
phonet
psample
qrtr net: qrtr: Fix an uninit variable access bug in qrtr_tx_resume() 2023-04-13 09:35:30 +02:00
rds
rfkill net: rfkill-gpio: Add explicit include for of.h 2023-04-06 20:36:27 +02:00
rose
rxrpc Including fixes from netfilter. 2023-05-05 19:12:01 -07:00
sched net/sched: flower: fix error handler on replace 2023-05-05 10:01:31 +01:00
sctp sctp: delete the nested flexible array hmac 2023-04-21 08:19:30 +01:00
smc net: deal with most data-races in sk_wait_event() 2023-05-10 10:03:32 +01:00
strparser
sunrpc NFSD 6.4 Release Notes 2023-04-29 11:04:14 -07:00
switchdev
tipc tipc: check the bearer min mtu properly when setting it by netlink 2023-05-15 10:21:20 +01:00
tls net: deal with most data-races in sk_wait_event() 2023-05-10 10:03:32 +01:00
unix af_unix: Fix data races around sk->sk_shutdown. 2023-05-10 19:06:53 -07:00
vmw_vsock vsock: avoid to close connected socket after the timeout 2023-05-12 10:04:10 +01:00
wireless Driver core changes for 6.4-rc1 2023-04-27 11:53:57 -07:00
x25
xdp bpf-next-for-netdev 2023-04-13 16:43:38 -07:00
xfrm ipsec-2023-05-16 2023-05-16 20:52:35 -07:00
compat.c net/compat: Update msg_control_is_user when setting a kernel pointer 2023-04-14 11:09:27 +01:00
devres.c
Kconfig net/handshake: Add Kunit tests for the handshake consumer API 2023-04-19 18:48:48 -07:00
Kconfig.debug
Makefile net/handshake: Create a NETLINK service for handling handshake requests 2023-04-19 18:48:48 -07:00
socket.c net: annotate sk->sk_err write from do_recvmmsg() 2023-05-10 09:58:29 +01:00
sysctl_net.c