kernel/linux.git/net/sctp, branch v5.10.257

sctp: move SCTP_CMD_ASSOC_SHKEY right after SCTP_CMD_PEER_INIT

2026-02-06T15:40:03+00:00

[ Upstream commit a80c9d945aef55b23b54838334345f20251dad83 ] A null-ptr-deref was reported in the SCTP transmit path when SCTP-AUTH key initialization fails: ================================================================== KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 0 PID: 16 Comm: ksoftirqd/0 Tainted: G W 6.6.0 #2 RIP: 0010:sctp_packet_bundle_auth net/sctp/output.c:264 [inline] RIP: 0010:sctp_packet_append_chunk+0xb36/0x1260 net/sctp/output.c:401 Call Trace: sctp_packet_transmit_chunk+0x31/0x250 net/sctp/output.c:189 sctp_outq_flush_data+0xa29/0x26d0 net/sctp/outqueue.c:1111 sctp_outq_flush+0xc80/0x1240 net/sctp/outqueue.c:1217 sctp_cmd_interpreter.isra.0+0x19a5/0x62c0 net/sctp/sm_sideeffect.c:1787 sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline] sctp_do_sm+0x1a3/0x670 net/sctp/sm_sideeffect.c:1169 sctp_assoc_bh_rcv+0x33e/0x640 net/sctp/associola.c:1052 sctp_inq_push+0x1dd/0x280 net/sctp/inqueue.c:88 sctp_rcv+0x11ae/0x3100 net/sctp/input.c:243 sctp6_rcv+0x3d/0x60 net/sctp/ipv6.c:1127 The issue is triggered when sctp_auth_asoc_init_active_key() fails in sctp_sf_do_5_1C_ack() while processing an INIT_ACK. In this case, the command sequence is currently: - SCTP_CMD_PEER_INIT - SCTP_CMD_TIMER_STOP (T1_INIT) - SCTP_CMD_TIMER_START (T1_COOKIE) - SCTP_CMD_NEW_STATE (COOKIE_ECHOED) - SCTP_CMD_ASSOC_SHKEY - SCTP_CMD_GEN_COOKIE_ECHO If SCTP_CMD_ASSOC_SHKEY fails, asoc->shkey remains NULL, while asoc->peer.auth_capable and asoc->peer.peer_chunks have already been set by SCTP_CMD_PEER_INIT. This allows a DATA chunk with auth = 1 and shkey = NULL to be queued by sctp_datamsg_from_user(). Since command interpretation stops on failure, no COOKIE_ECHO should been sent via SCTP_CMD_GEN_COOKIE_ECHO. However, the T1_COOKIE timer has already been started, and it may enqueue a COOKIE_ECHO into the outqueue later. As a result, the DATA chunk can be transmitted together with the COOKIE_ECHO in sctp_outq_flush_data(), leading to the observed issue. Similar to the other places where it calls sctp_auth_asoc_init_active_key() right after sctp_process_init(), this patch moves the SCTP_CMD_ASSOC_SHKEY immediately after SCTP_CMD_PEER_INIT, before stopping T1_INIT and starting T1_COOKIE. This ensures that if shared key generation fails, authenticated DATA cannot be sent. It also allows the T1_INIT timer to retransmit INIT, giving the client another chance to process INIT_ACK and retry key setup. Fixes: 730fc3d05cd4 ("[SCTP]: Implete SCTP-AUTH parameter processing") Reported-by: Zhen Chen Tested-by: Zhen Chen Signed-off-by: Xin Long Link: https://patch.msgid.link/44881224b375aa8853f5e19b4055a1a56d895813.1768324226.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

sctp: sm_statefuns: Fix spelling mistakes

2026-02-06T15:40:03+00:00

[ Upstream commit 0c2c366e0ec55533decb00d0f1ea1cbc42247e7b ] Fix some spelling mistakes in comments: genereate ==> generate correclty ==> correctly boundries ==> boundaries failes ==> fails isses ==> issues assocition ==> association signe ==> sign assocaition ==> association managemement ==> management restransmissions ==> retransmission sideffect ==> sideeffect bomming ==> booming chukns ==> chunks SHUDOWN ==> SHUTDOWN violationg ==> violating explcitly ==> explicitly CHunk ==> Chunk Signed-off-by: Zheng Yongjun Link: https://lore.kernel.org/r/20210601020801.3625358-1-zhengyongjun3@huawei.com Signed-off-by: Jakub Kicinski Stable-dep-of: a80c9d945aef ("sctp: move SCTP_CMD_ASSOC_SHKEY right after SCTP_CMD_PEER_INIT") Signed-off-by: Sasha Levin

sctp: prevent possible shift-out-of-bounds in sctp_transport_update_rto

2025-12-06T21:08:17+00:00

[ Upstream commit 1534ff77757e44bcc4b98d0196bc5c0052fce5fa ] syzbot reported a possible shift-out-of-bounds [1] Blamed commit added rto_alpha_max and rto_beta_max set to 1000. It is unclear if some sctp users are setting very large rto_alpha and/or rto_beta. In order to prevent user regression, perform the test at run time. Also add READ_ONCE() annotations as sysctl values can change under us. [1] UBSAN: shift-out-of-bounds in net/sctp/transport.c:509:41 shift exponent 64 is too large for 32-bit type 'unsigned int' CPU: 0 UID: 0 PID: 16704 Comm: syz.2.2320 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:233 [inline] __ubsan_handle_shift_out_of_bounds+0x27f/0x420 lib/ubsan.c:494 sctp_transport_update_rto.cold+0x1c/0x34b net/sctp/transport.c:509 sctp_check_transmitted+0x11c4/0x1c30 net/sctp/outqueue.c:1502 sctp_outq_sack+0x4ef/0x1b20 net/sctp/outqueue.c:1338 sctp_cmd_process_sack net/sctp/sm_sideeffect.c:840 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1372 [inline] Fixes: b58537a1f562 ("net: sctp: fix permissions for rto_alpha and rto_beta knobs") Reported-by: syzbot+f8c46c8b2b7f6e076e99@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/690c81ae.050a0220.3d0d33.014e.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Daniel Borkmann Acked-by: Xin Long Link: https://patch.msgid.link/20251106111054.3288127-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

sctp: Hold sock lock while iterating over address list

2025-12-06T21:08:16+00:00

[ Upstream commit f1fc201148c7e684c10a72b6a3375597f28d1ef6 ] Move address list traversal in inet_assoc_attr_size() under the sock lock to avoid holding the RCU read lock. Suggested-by: Xin Long Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Stefan Wiehler Acked-by: Xin Long Link: https://patch.msgid.link/20251028161506.3294376-4-stefan.wiehler@nokia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

sctp: hold endpoint before calling cb in sctp_transport_lookup_process

2025-12-06T21:08:16+00:00

[ Upstream commit f9d31c4cf4c11ff10317f038b9c6f7c3bda6cdd4 ] The same fix in commit 5ec7d18d1813 ("sctp: use call_rcu to free endpoint") is also needed for dumping one asoc and sock after the lookup. Fixes: 86fdb3448cc1 ("sctp: ensure ep is not destroyed before doing the dump") Signed-off-by: Xin Long Signed-off-by: David S. Miller Stable-dep-of: f1fc201148c7 ("sctp: Hold sock lock while iterating over address list") Signed-off-by: Sasha Levin

net: Use nlmsg_unicast() instead of netlink_unicast()

2025-12-06T21:08:16+00:00

[ Upstream commit 01757f536ac825e3614d583fee9acb48c64ed084 ] It has 'if (err >0 )' statement in nlmsg_unicast(), so use nlmsg_unicast() instead of netlink_unicast(), this looks more concise. v2: remove the change in netfilter. Signed-off-by: Yajun Deng Reviewed-by: David Ahern Signed-off-by: David S. Miller Stable-dep-of: f1fc201148c7 ("sctp: Hold sock lock while iterating over address list") Signed-off-by: Sasha Levin

net: sctp: Fix some typos

2025-12-06T21:08:16+00:00

[ Upstream commit 21c00a186fac6e035eef5e6751f1e2d2609f969c ] Modify "unkown" to "unknown" in net/sctp/sm_make_chunk.c and Modify "orginal" to "original" in net/sctp/socket.c. Reported-by: Hulk Robot Signed-off-by: Lu Wei Signed-off-by: David S. Miller Stable-dep-of: f1fc201148c7 ("sctp: Hold sock lock while iterating over address list") Signed-off-by: Sasha Levin

sctp: Prevent TOCTOU out-of-bounds write

2025-12-06T21:08:16+00:00

[ Upstream commit 95aef86ab231f047bb8085c70666059b58f53c09 ] For the following path not holding the sock lock, sctp_diag_dump() -> sctp_for_each_endpoint() -> sctp_ep_dump() make sure not to exceed bounds in case the address list has grown between buffer allocation (time-of-check) and write (time-of-use). Suggested-by: Kuniyuki Iwashima Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Stefan Wiehler Reviewed-by: Kuniyuki Iwashima Acked-by: Xin Long Link: https://patch.msgid.link/20251028161506.3294376-3-stefan.wiehler@nokia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

sctp: Hold RCU read lock while iterating over address list

2025-12-06T21:08:16+00:00

[ Upstream commit 38f50242bf0f237cdc262308d624d333286ec3c5 ] With CONFIG_PROVE_RCU_LIST=y and by executing $ netcat -l --sctp & $ netcat --sctp localhost & $ ss --sctp one can trigger the following Lockdep-RCU splat(s): WARNING: suspicious RCU usage 6.18.0-rc1-00093-g7f864458e9a6 #5 Not tainted ----------------------------- net/sctp/diag.c:76 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by ss/215: #0: ffff9c740828bec0 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{4:4}, at: __netlink_dump_start+0x84/0x2b0 #1: ffff9c7401d72cd0 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_sock_dump+0x38/0x200 stack backtrace: CPU: 0 UID: 0 PID: 215 Comm: ss Not tainted 6.18.0-rc1-00093-g7f864458e9a6 #5 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack_lvl+0x5d/0x90 lockdep_rcu_suspicious.cold+0x4e/0xa3 inet_sctp_diag_fill.isra.0+0x4b1/0x5d0 sctp_sock_dump+0x131/0x200 sctp_transport_traverse_process+0x170/0x1b0 ? __pfx_sctp_sock_filter+0x10/0x10 ? __pfx_sctp_sock_dump+0x10/0x10 sctp_diag_dump+0x103/0x140 __inet_diag_dump+0x70/0xb0 netlink_dump+0x148/0x490 __netlink_dump_start+0x1f3/0x2b0 inet_diag_handler_cmd+0xcd/0x100 ? __pfx_inet_diag_dump_start+0x10/0x10 ? __pfx_inet_diag_dump+0x10/0x10 ? __pfx_inet_diag_dump_done+0x10/0x10 sock_diag_rcv_msg+0x18e/0x320 ? __pfx_sock_diag_rcv_msg+0x10/0x10 netlink_rcv_skb+0x4d/0x100 netlink_unicast+0x1d7/0x2b0 netlink_sendmsg+0x203/0x450 ____sys_sendmsg+0x30c/0x340 ___sys_sendmsg+0x94/0xf0 __sys_sendmsg+0x83/0xf0 do_syscall_64+0xbb/0x390 entry_SYSCALL_64_after_hwframe+0x77/0x7f ... Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Stefan Wiehler Reviewed-by: Kuniyuki Iwashima Acked-by: Xin Long Link: https://patch.msgid.link/20251028161506.3294376-2-stefan.wiehler@nokia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

sctp: avoid NULL dereference when chunk data buffer is missing

2025-10-29T13:01:21+00:00

[ Upstream commit 441f0647f7673e0e64d4910ef61a5fb8f16bfb82 ] chunk->skb pointer is dereferenced in the if-block where it's supposed to be NULL only. chunk->skb can only be NULL if chunk->head_skb is not. Check for frag_list instead and do it just before replacing chunk->skb. We're sure that otherwise chunk->skb is non-NULL because of outer if() condition. Fixes: 90017accff61 ("sctp: Add GSO support") Signed-off-by: Alexey Simakov Acked-by: Marcelo Ricardo Leitner Link: https://patch.msgid.link/20251021130034.6333-1-bigalex934@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin