linux/net/sctp
Xin Long 057a10fa1f sctp: change to hold/put transport for proto_unreach_timer
A call trace was found in Hangbin's Codenomicon testing with debug kernel:

  [ 2615.981988] ODEBUG: free active (active state 0) object type: timer_list hint: sctp_generate_proto_unreach_event+0x0/0x3a0 [sctp]
  [ 2615.995050] WARNING: CPU: 17 PID: 0 at lib/debugobjects.c:328 debug_print_object+0x199/0x2b0
  [ 2616.095934] RIP: 0010:debug_print_object+0x199/0x2b0
  [ 2616.191533] Call Trace:
  [ 2616.194265]  <IRQ>
  [ 2616.202068]  debug_check_no_obj_freed+0x25e/0x3f0
  [ 2616.207336]  slab_free_freelist_hook+0xeb/0x140
  [ 2616.220971]  kfree+0xd6/0x2c0
  [ 2616.224293]  rcu_do_batch+0x3bd/0xc70
  [ 2616.243096]  rcu_core+0x8b9/0xd00
  [ 2616.256065]  __do_softirq+0x23d/0xacd
  [ 2616.260166]  irq_exit+0x236/0x2a0
  [ 2616.263879]  smp_apic_timer_interrupt+0x18d/0x620
  [ 2616.269138]  apic_timer_interrupt+0xf/0x20
  [ 2616.273711]  </IRQ>

This is because it holds asoc when transport->proto_unreach_timer starts
and puts asoc when the timer stops, and without holding transport the
transport could be freed when the timer is still running.

So fix it by holding/putting transport instead for proto_unreach_timer
in transport, just like other timers in transport.

v1->v2:
  - Also use sctp_transport_put() for the "out_unlock:" path in
    sctp_generate_proto_unreach_event(), as Marcelo noticed.

Fixes: 50b5d6ad63 ("sctp: Fix a race between ICMP protocol unreachable and connect()")
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Link: https://lore.kernel.org/r/102788809b554958b13b95d33440f5448113b8d6.1605331373.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-14 11:57:12 -08:00
..
associola.c net: sctp: associola.c: delete duplicated words 2020-08-24 16:21:43 -07:00
auth.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-10-08 15:44:50 -07:00
bind_addr.c net: sctp: bind_addr.c: delete duplicated word 2020-08-24 16:21:43 -07:00
chunk.c net: sctp: chunk.c: delete duplicated word 2020-08-24 16:21:43 -07:00
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: change to hold/put transport for proto_unreach_timer 2020-11-14 11:57:12 -08:00
inqueue.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
ipv6.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
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 treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
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 net: sctp: protocol.c: delete duplicated words + punctuation 2020-08-24 16:21:43 -07:00
sm_make_chunk.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-04 21:28:59 -07:00
sm_sideeffect.c sctp: change to hold/put transport for proto_unreach_timer 2020-11-14 11:57:12 -08:00
sm_statefuns.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
sm_statetable.c sctp: remove net sctp.x_enable working as a global switch 2019-08-19 18:27:29 -07:00
socket.c net: sctp: Fix IPv6 ancestor_size calc in sctp_copy_descendant 2020-09-20 14:15:12 -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 net: sctp: Fix negotiation of the number of data streams. 2020-08-20 16:37:37 -07:00
sysctl.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
transport.c sctp: change to hold/put transport for proto_unreach_timer 2020-11-14 11:57:12 -08:00
tsnmap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
ulpevent.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-31 17:48:46 -07:00
ulpqueue.c net: sctp: ulpqueue.c: delete duplicated word 2020-08-24 16:21:43 -07:00