linux/net/sctp
Neil Horman 20a785aa52 sctp: Don't add the shutdown timer if its already been added
This BUG halt was reported a while back, but the patch somehow got
missed:

PID: 2879   TASK: c16adaa0  CPU: 1   COMMAND: "sctpn"
 #0 [f418dd28] crash_kexec at c04a7d8c
 #1 [f418dd7c] oops_end at c0863e02
 #2 [f418dd90] do_invalid_op at c040aaca
 #3 [f418de28] error_code (via invalid_op) at c08631a5
    EAX: f34baac0  EBX: 00000090  ECX: f418deb0  EDX: f5542950  EBP: 00000000
    DS:  007b      ESI: f34ba800  ES:  007b      EDI: f418dea0  GS:  00e0
    CS:  0060      EIP: c046fa5e  ERR: ffffffff  EFLAGS: 00010286
 #4 [f418de5c] add_timer at c046fa5e
 #5 [f418de68] sctp_do_sm at f8db8c77 [sctp]
 #6 [f418df30] sctp_primitive_SHUTDOWN at f8dcc1b5 [sctp]
 #7 [f418df48] inet_shutdown at c080baf9
 #8 [f418df5c] sys_shutdown at c079eedf
 #9 [f418df70] sys_socketcall at c079fe88
    EAX: ffffffda  EBX: 0000000d  ECX: bfceea90  EDX: 0937af98
    DS:  007b      ESI: 0000000c  ES:  007b      EDI: b7150ae4
    SS:  007b      ESP: bfceea7c  EBP: bfceeaa8  GS:  0033
    CS:  0073      EIP: b775c424  ERR: 00000066  EFLAGS: 00000282

It appears that the side effect that starts the shutdown timer was processed
multiple times, which can happen as multiple paths can trigger it.  This of
course leads to the BUG halt in add_timer getting called.

Fix seems pretty straightforward, just check before the timer is added if its
already been started.  If it has mod the timer instead to min(current
expiration, new expiration)

Its been tested but not confirmed to fix the problem, as the issue has only
occured in production environments where test kernels are enjoined from being
installed.  It appears to be a sane fix to me though.  Also, recentely,
Jere found a reproducer posted on list to confirm that this resolves the
issues

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: jere.leppanen@nokia.com
CC: marcelo.leitner@gmail.com
CC: netdev@vger.kernel.org
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-19 15:46:52 -07:00
..
associola.c sctp: get netns from asoc and ep base 2019-12-09 20:14:01 -08:00
auth.c sctp: add sctp_auth_init and sctp_auth_free 2019-08-19 18:27:29 -07:00
bind_addr.c sctp: remove rcu_read_lock from sctp_bind_addr_state 2019-07-08 20:18:11 -07:00
chunk.c sctp: get netns from asoc and ep base 2019-12-09 20:14:01 -08:00
debug.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
diag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 22:34:48 -07:00
endpointola.c sctp: get netns from asoc and ep base 2019-12-09 20:14:01 -08:00
input.c sctp: Add missing annotation for sctp_err_finish() 2020-02-24 13:26:48 -08:00
inqueue.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
ipv6.c sctp: fix possibly using a bad saddr with a given dst 2020-03-29 22:01:43 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile sctp: rename sctp_diag.c as diag.c 2018-02-13 13:56:31 -05:00
objcnt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-07 11:00:14 -07:00
output.c sctp: get netns from asoc and ep base 2019-12-09 20:14:01 -08:00
outqueue.c sctp: add enabled check for path tracepoint loop. 2019-12-30 20:33:05 -08:00
primitive.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
proc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
protocol.c sctp: fix possibly using a bad saddr with a given dst 2020-03-29 22:01:43 -07:00
sm_make_chunk.c sctp: Fix SHUTDOWN CTSN Ack in the peer restart case 2020-04-22 19:27:40 -07:00
sm_sideeffect.c sctp: Don't add the shutdown timer if its already been added 2020-05-19 15:46:52 -07:00
sm_statefuns.c sctp: Fix bundling of SHUTDOWN with COOKIE-ACK 2020-04-22 19:27:40 -07:00
sm_statetable.c sctp: remove net sctp.x_enable working as a global switch 2019-08-19 18:27:29 -07:00
socket.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-30 20:48:43 -07:00
stream_interleave.c sctp: get netns from asoc and ep base 2019-12-09 20:14:01 -08:00
stream_sched_prio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
stream_sched_rr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
stream_sched.c sctp: rename asoc intl_enable to asoc peer.intl_capable 2019-07-08 20:16:25 -07:00
stream.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-31 13:37:13 -08:00
sysctl.c sctp: add support for Primary Path Switchover 2019-11-08 14:18:32 -08:00
transport.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-31 13:37:13 -08:00
tsnmap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
ulpevent.c sctp: add SCTP_SEND_FAILED_EVENT event 2019-10-09 17:06:58 -07:00
ulpqueue.c sctp: get netns from asoc and ep base 2019-12-09 20:14:01 -08:00