linux/net
Karl Heiss 635682a144 sctp: Prevent soft lockup when sctp_accept() is called during a timeout event
A case can occur when sctp_accept() is called by the user during
a heartbeat timeout event after the 4-way handshake.  Since
sctp_assoc_migrate() changes both assoc->base.sk and assoc->ep, the
bh_sock_lock in sctp_generate_heartbeat_event() will be taken with
the listening socket but released with the new association socket.
The result is a deadlock on any future attempts to take the listening
socket lock.

Note that this race can occur with other SCTP timeouts that take
the bh_lock_sock() in the event sctp_accept() is called.

 BUG: soft lockup - CPU#9 stuck for 67s! [swapper:0]
 ...
 RIP: 0010:[<ffffffff8152d48e>]  [<ffffffff8152d48e>] _spin_lock+0x1e/0x30
 RSP: 0018:ffff880028323b20  EFLAGS: 00000206
 RAX: 0000000000000002 RBX: ffff880028323b20 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff880028323be0 RDI: ffff8804632c4b48
 RBP: ffffffff8100bb93 R08: 0000000000000000 R09: 0000000000000000
 R10: ffff880610662280 R11: 0000000000000100 R12: ffff880028323aa0
 R13: ffff8804383c3880 R14: ffff880028323a90 R15: ffffffff81534225
 FS:  0000000000000000(0000) GS:ffff880028320000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
 CR2: 00000000006df528 CR3: 0000000001a85000 CR4: 00000000000006e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process swapper (pid: 0, threadinfo ffff880616b70000, task ffff880616b6cab0)
 Stack:
 ffff880028323c40 ffffffffa01c2582 ffff880614cfb020 0000000000000000
 <d> 0100000000000000 00000014383a6c44 ffff8804383c3880 ffff880614e93c00
 <d> ffff880614e93c00 0000000000000000 ffff8804632c4b00 ffff8804383c38b8
 Call Trace:
 <IRQ>
 [<ffffffffa01c2582>] ? sctp_rcv+0x492/0xa10 [sctp]
 [<ffffffff8148c559>] ? nf_iterate+0x69/0xb0
 [<ffffffff814974a0>] ? ip_local_deliver_finish+0x0/0x2d0
 [<ffffffff8148c716>] ? nf_hook_slow+0x76/0x120
 [<ffffffff814974a0>] ? ip_local_deliver_finish+0x0/0x2d0
 [<ffffffff8149757d>] ? ip_local_deliver_finish+0xdd/0x2d0
 [<ffffffff81497808>] ? ip_local_deliver+0x98/0xa0
 [<ffffffff81496ccd>] ? ip_rcv_finish+0x12d/0x440
 [<ffffffff81497255>] ? ip_rcv+0x275/0x350
 [<ffffffff8145cfeb>] ? __netif_receive_skb+0x4ab/0x750
 ...

With lockdep debugging:

 =====================================
 [ BUG: bad unlock balance detected! ]
 -------------------------------------
 CslRx/12087 is trying to release lock (slock-AF_INET) at:
 [<ffffffffa01bcae0>] sctp_generate_timeout_event+0x40/0xe0 [sctp]
 but there are no more locks to release!

 other info that might help us debug this:
 2 locks held by CslRx/12087:
 #0:  (&asoc->timers[i]){+.-...}, at: [<ffffffff8108ce1f>] run_timer_softirq+0x16f/0x3e0
 #1:  (slock-AF_INET){+.-...}, at: [<ffffffffa01bcac3>] sctp_generate_timeout_event+0x23/0xe0 [sctp]

Ensure the socket taken is also the same one that is released by
saving a copy of the socket before entering the timeout event
critical section.

Signed-off-by: Karl Heiss <kheiss@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-28 21:03:40 -07:00
..
6lowpan 6lowpan: move module_init into core functionality 2015-08-11 22:05:36 +02:00
9p net/9p: Remove ib_get_dma_mr calls 2015-08-30 18:12:36 -04:00
802
8021q net: 8021q: convert to using IFF_NO_QUEUE 2015-08-18 11:55:06 -07:00
appletalk
atm atm: deal with setting entry before mkip was called 2015-09-17 22:13:32 -07:00
ax25 NET: AX.25: Stop heartbeat timer on disconnect. 2015-07-15 15:59:58 -07:00
batman-adv batman-adv: turn batadv_neigh_node_get() into local function 2015-08-27 20:15:34 +02:00
bluetooth Bluetooth: Delay check for conn->smp in smp_conn_security() 2015-09-17 12:28:27 +02:00
bridge bridge: fix igmpv3 / mldv2 report parsing 2015-09-11 15:08:20 -07:00
caif net: caif: convert to using IFF_NO_QUEUE 2015-08-18 11:55:07 -07:00
can can: replace timestamp as unique skb attribute 2015-07-12 21:13:22 +02:00
ceph libceph: don't access invalid memory in keepalive2 path 2015-09-17 20:14:15 +03:00
core net: fix net_device refcounting 2015-09-24 23:04:53 -07:00
dcb
dccp tcp/dccp: fix timewait races in timer handling 2015-09-21 16:32:29 -07:00
decnet net: ipv6: use common fib_default_rule_pref 2015-09-09 14:19:50 -07:00
dns_resolver
dsa net: fix net_device refcounting 2015-09-24 23:04:53 -07:00
ethernet flow_dissector: Add flags argument to skb_flow_dissector functions 2015-09-01 15:06:22 -07:00
hsr net: hsr: convert to using IFF_NO_QUEUE 2015-08-18 11:55:07 -07:00
ieee802154 Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2015-08-29 13:15:03 -07:00
ipv4 net: Fix panic in icmp_route_lookup 2015-09-25 21:44:02 -07:00
ipv6 ip6_tunnel: Reduce log level in ip6_tnl_err() to debug 2015-09-24 16:08:37 -07:00
ipx
irda irda: use msecs_to_jiffies for conversion to jiffies 2015-05-25 17:46:21 -04:00
iucv
key net: Fix RCU splat in af_key 2015-08-24 14:48:10 -07:00
l2tp
lapb
llc tcp: fix recv with flags MSG_WAITALL | MSG_PEEK 2015-07-27 01:06:53 -07:00
mac80211 mac80211: reset CQM history upon reconfiguration 2015-09-22 15:22:50 +02:00
mac802154 ieee802154: add ack request default handling 2015-08-10 20:43:06 +02:00
mpls mpls: fix mpls_net_init memory leak 2015-08-31 12:45:09 -07:00
netfilter netfilter: nf_log: wait for rcu grace after logger unregistration 2015-09-17 13:37:31 +02:00
netlabel
netlink netlink: Replace rhash_portid with bound 2015-09-24 12:07:08 -07:00
netrom netfilter: Remove spurios included of netfilter.h 2015-06-18 21:14:32 +02:00
nfc nfc: netlink: Add capability to reply to vendor_cmd with data 2015-08-20 22:00:11 +02:00
openvswitch openvswitch: Zero flows on allocation. 2015-09-22 17:33:41 -07:00
packet Fix AF_PACKET ABI breakage in 4.2 2015-09-23 14:33:55 -07:00
phonet
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-09-10 13:53:15 -07:00
rfkill rfkill: Copy "all" global state to other types 2015-09-04 14:26:56 +02:00
rose Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-24 02:58:51 -07:00
rxrpc
sched net: revert "net_sched: move tp->root allocation into fw_init()" 2015-09-24 14:33:30 -07:00
sctp sctp: Prevent soft lockup when sctp_accept() is called during a timeout event 2015-09-28 21:03:40 -07:00
sunrpc NFS client bugfixes for Linux 4.3 2015-09-25 11:33:52 -07:00
switchdev switchdev: fix return value of switchdev_port_fdb_dump in case of error 2015-09-05 22:02:11 -07:00
tipc tipc: reinitialize pointer after skb linearize 2015-09-20 22:31:20 -07:00
unix net/unix: support SCM_SECURITY for stream sockets 2015-06-10 22:49:20 -07:00
vmw_vsock
wimax net:wimax: Fix doucble word "the the" in networking.xml 2015-08-09 22:43:52 -07:00
wireless cfg80211: regulatory: restore proper user alpha2 2015-09-04 14:29:25 +02:00
x25
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-09-03 08:08:17 -07:00
compat.c
Kconfig lwtunnel: infrastructure for handling light weight tunnels like mpls 2015-07-21 10:39:03 -07:00
Makefile
socket.c
sysctl_net.c