linux/net/sctp
Xin Long 2584024b23 sctp: check send stream number after wait_for_sndbuf
This patch fixes a corner case where the asoc out stream count may change
after wait_for_sndbuf.

When the main thread in the client starts a connection, if its out stream
count is set to N while the in stream count in the server is set to N - 2,
another thread in the client keeps sending the msgs with stream number
N - 1, and waits for sndbuf before processing INIT_ACK.

However, after processing INIT_ACK, the out stream count in the client is
shrunk to N - 2, the same to the in stream count in the server. The crash
occurs when the thread waiting for sndbuf is awake and sends the msg in a
non-existing stream(N - 1), the call trace is as below:

  KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
  Call Trace:
   <TASK>
   sctp_cmd_send_msg net/sctp/sm_sideeffect.c:1114 [inline]
   sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1777 [inline]
   sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline]
   sctp_do_sm+0x197d/0x5310 net/sctp/sm_sideeffect.c:1170
   sctp_primitive_SEND+0x9f/0xc0 net/sctp/primitive.c:163
   sctp_sendmsg_to_asoc+0x10eb/0x1a30 net/sctp/socket.c:1868
   sctp_sendmsg+0x8d4/0x1d90 net/sctp/socket.c:2026
   inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:825
   sock_sendmsg_nosec net/socket.c:722 [inline]
   sock_sendmsg+0xde/0x190 net/socket.c:745

The fix is to add an unlikely check for the send stream number after the
thread wakes up from the wait_for_sndbuf.

Fixes: 5bbbbe32a4 ("sctp: introduce stream scheduler foundations")
Reported-by: syzbot+47c24ca20a2fa01f082e@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-02 13:44:58 +01:00
..
associola.c sctp: remove unnecessary NULL check in sctp_association_init() 2022-10-20 21:43:10 -07:00
auth.c sctp: handle the error returned from sctp_auth_asoc_init_active_key 2022-09-30 12:36:40 +01:00
bind_addr.c sctp: fail if no bound addresses can be used for a given scope 2023-01-24 18:32:33 -08:00
chunk.c net: sctp: chunk.c: delete duplicated word 2020-08-24 16:21:43 -07:00
debug.c sctp: add the probe timer in transport for PLPMTUD 2021-06-22 11:28:52 -07:00
diag.c sctp: sctp_sock_filter(): avoid list_entry() on possibly empty list 2023-02-10 19:28:29 -08:00
endpointola.c sctp: add dif and sdif check in asoc and ep lookup 2022-11-18 11:42:54 +00:00
input.c sctp: add dif and sdif check in asoc and ep lookup 2022-11-18 11:42:54 +00:00
inqueue.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
ipv6.c net: no longer support SOCK_REFCNT_DEBUG feature 2023-02-15 10:25:21 +00:00
Kconfig sctp: create udp4 sock and add its encap_rcv 2020-10-30 15:23:52 -07:00
Makefile
objcnt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
offload.c sctp: remove the NETIF_F_SG flag before calling skb_segment 2021-01-16 19:05:59 -08:00
output.c net: allow gso_max_size to exceed 65536 2022-05-16 10:18:55 +01:00
outqueue.c sctp: clear out_curr if all frag chunks of current msg are pruned 2022-11-07 19:59:01 -08:00
primitive.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
proc.c sctp: move hlist_node and hashent out of sctp_ep_common 2021-12-23 11:15:30 +00:00
protocol.c net: no longer support SOCK_REFCNT_DEBUG feature 2023-02-15 10:25:21 +00:00
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: sm_statefuns: Remove pointer casts of the same type 2022-11-17 13:04:37 +01:00
sm_statetable.c sctp: add the probe timer in transport for PLPMTUD 2021-06-22 11:28:52 -07:00
socket.c sctp: check send stream number after wait_for_sndbuf 2023-04-02 13:44:58 +01:00
stream_interleave.c sctp: remove unnecessary NULL checks in sctp_enqueue_event() 2022-10-20 21:43:10 -07:00
stream_sched_prio.c sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop 2023-02-23 12:59:40 -08:00
stream_sched_rr.c sctp: delete free member from struct sctp_sched_ops 2022-12-01 20:14:23 -08:00
stream_sched.c sctp: delete free member from struct sctp_sched_ops 2022-12-01 20:14:23 -08:00
stream.c sctp: fix memory leak in sctp_stream_outq_migrate() 2022-11-29 08:30:50 -08:00
sysctl.c sctp: sysctl: make extra pointers netns aware 2022-12-12 12:57:29 -08:00
transport.c sctp: do not check hb_timer.expires when resetting hb_timer 2023-01-31 21:01:28 -08:00
tsnmap.c net: sctp: trivial: fix typo in comment 2021-03-04 13:48:32 -08:00
ulpevent.c net: remove noblock parameter from recvmsg() entities 2022-04-12 15:00:25 +02:00
ulpqueue.c sctp: remove unnecessary NULL check in sctp_ulpq_tail_event() 2022-10-20 21:43:10 -07:00