linux/net/sctp
Eric Dumazet 386507cb6f sctp: add mutual exclusion in proc_sctp_do_udp_port()
commit 10206302af upstream.

We must serialize calls to sctp_udp_sock_stop() and sctp_udp_sock_start()
or risk a crash as syzbot reported:

Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
CPU: 1 UID: 0 PID: 6551 Comm: syz.1.44 Not tainted 6.14.0-syzkaller-g7f2ff7b62617 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
 RIP: 0010:kernel_sock_shutdown+0x47/0x70 net/socket.c:3653
Call Trace:
 <TASK>
  udp_tunnel_sock_release+0x68/0x80 net/ipv4/udp_tunnel_core.c:181
  sctp_udp_sock_stop+0x71/0x160 net/sctp/protocol.c:930
  proc_sctp_do_udp_port+0x264/0x450 net/sctp/sysctl.c:553
  proc_sys_call_handler+0x3d0/0x5b0 fs/proc/proc_sysctl.c:601
  iter_file_splice_write+0x91c/0x1150 fs/splice.c:738
  do_splice_from fs/splice.c:935 [inline]
  direct_splice_actor+0x18f/0x6c0 fs/splice.c:1158
  splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102
  do_splice_direct_actor fs/splice.c:1201 [inline]
  do_splice_direct+0x174/0x240 fs/splice.c:1227
  do_sendfile+0xafd/0xe50 fs/read_write.c:1368
  __do_sys_sendfile64 fs/read_write.c:1429 [inline]
  __se_sys_sendfile64 fs/read_write.c:1415 [inline]
  __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1415
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]

Fixes: 046c052b47 ("sctp: enable udp tunneling socks")
Reported-by: syzbot+fae49d997eb56fa7c74d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/67ea5c01.050a0220.1547ec.012b.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20250331091532.224982-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[Minor conflict resolved due to code context change.]
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-05-22 14:10:09 +02:00
..
associola.c net/sctp: Prevent autoclose integer overflow in sctp_association_init() 2025-01-09 13:30:06 +01:00
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 2023-02-01 08:34:46 +01:00
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 2023-02-22 12:59:51 +01:00
endpointola.c sctp: use call_rcu to free endpoint 2021-12-25 17:13:37 +00:00
input.c sctp: Fix null-ptr-deref in reuseport_add_sock(). 2024-08-14 13:52:43 +02:00
inqueue.c net: sctp: fix skb leak in sctp_inq_free() 2024-08-29 17:30:20 +02:00
ipv6.c ipv6: Remove __ipv6_only_sock(). 2022-04-22 12:47:50 +01:00
Kconfig sctp: create udp4 sock and add its encap_rcv 2020-10-30 15:23:52 -07:00
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 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: annotate data-races around sk->sk_wmem_queued 2023-09-19 12:28:00 +02:00
protocol.c ipv4: Drop tos parameter from flowi4_update_output() 2025-05-18 08:21:21 +02:00
sm_make_chunk.c sctp: account stream padding length for reconf chunk 2021-10-14 07:15:22 -07:00
sm_sideeffect.c sctp: handle invalid error codes without calling BUG() 2023-09-13 09:42:25 +02:00
sm_statefuns.c sctp: properly validate chunk size in sctp_sf_ootb() 2024-11-14 13:15:11 +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: detect and prevent references to a freed transport in sendmsg 2025-04-25 10:43:43 +02:00
stream.c sctp: Fix undefined behavior in left shift operation 2025-03-28 21:58:52 +01:00
stream_interleave.c sctp: fix a potential overflow in sctp_ifwdtsn_skip 2023-04-20 12:35:09 +02:00
stream_sched.c sctp: fix memory leak in sctp_stream_outq_migrate() 2022-11-29 08:30:50 -08:00
stream_sched_prio.c sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop 2023-03-11 13:55:26 +01:00
stream_sched_rr.c sctp: fix memory leak in sctp_stream_outq_migrate() 2022-11-29 08:30:50 -08:00
sysctl.c sctp: add mutual exclusion in proc_sctp_do_udp_port() 2025-05-22 14:10:09 +02:00
transport.c sctp: detect and prevent references to a freed transport in sendmsg 2025-04-25 10:43:43 +02:00
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 net: keep sk->sk_forward_alloc as small as possible 2022-06-10 16:21:27 -07:00