linux/net/sctp
Xin Long 165e3e17fe sctp: check asoc strreset_chunk in sctp_generate_reconf_event
A null pointer reference issue can be triggered when the response of a
stream reconf request arrives after the timer is triggered, such as:

  send Incoming SSN Reset Request --->
  CPU0:
   reconf timer is triggered,
   go to the handler code before hold sk lock
                            <--- reply with Outgoing SSN Reset Request
  CPU1:
   process Outgoing SSN Reset Request,
   and set asoc->strreset_chunk to NULL
  CPU0:
   continue the handler code, hold sk lock,
   and try to hold asoc->strreset_chunk, crash!

In Ying Xu's testing, the call trace is:

  [ ] BUG: kernel NULL pointer dereference, address: 0000000000000010
  [ ] RIP: 0010:sctp_chunk_hold+0xe/0x40 [sctp]
  [ ] Call Trace:
  [ ]  <IRQ>
  [ ]  sctp_sf_send_reconf+0x2c/0x100 [sctp]
  [ ]  sctp_do_sm+0xa4/0x220 [sctp]
  [ ]  sctp_generate_reconf_event+0xbd/0xe0 [sctp]
  [ ]  call_timer_fn+0x26/0x130

This patch is to fix it by returning from the timer handler if asoc
strreset_chunk is already set to NULL.

Fixes: 7b9438de0c ("sctp: add stream reconf timer")
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-23 22:34:17 +01:00
..
associola.c
auth.c sctp: move the active_key update after sh_keys is added 2021-08-03 11:43:43 +01:00
bind_addr.c
chunk.c
debug.c
diag.c sctp: fix kernel-infoleak for SCTP sockets 2022-03-10 14:46:42 -08:00
endpointola.c sctp: use call_rcu to free endpoint 2021-12-25 17:13:37 +00:00
input.c sctp: move hlist_node and hashent out of sctp_ep_common 2021-12-23 11:15:30 +00:00
inqueue.c
ipv6.c sctp: delete addr based on sin6_scope_id 2021-07-26 12:34:03 +01:00
Kconfig
Makefile
objcnt.c
offload.c
output.c net: annotate accesses to dev->gso_max_size 2021-11-22 12:49:42 +00:00
outqueue.c sctp: count singleton chunks in assoc user stats 2022-04-05 09:51:12 +02:00
primitive.c
proc.c sctp: move hlist_node and hashent out of sctp_ep_common 2021-12-23 11:15:30 +00:00
protocol.c include/linux/mm.h: move nr_free_buffer_pages from swap.h to mm.h 2021-11-06 13:30:43 -07:00
sm_make_chunk.c sctp: account stream padding length for reconf chunk 2021-10-14 07:15:22 -07:00
sm_sideeffect.c sctp: check asoc strreset_chunk in sctp_generate_reconf_event 2022-04-23 22:34:17 +01:00
sm_statefuns.c sctp: use the correct skb for security_sctp_assoc_request 2022-04-08 14:38:58 -07:00
sm_statetable.c
socket.c sctp: Initialize daddr on peeled off socket 2022-04-11 20:33:10 -07:00
stream_interleave.c
stream_sched_prio.c
stream_sched_rr.c
stream_sched.c
stream.c
sysctl.c
transport.c sctp: make the raise timer more simple and accurate 2021-11-25 21:00:45 -08:00
tsnmap.c
ulpevent.c
ulpqueue.c