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2023-10-10sctp: update hb timer immediately after users change hb_intervalXin Long
[ Upstream commit 1f4e803cd9c9166eb8b6c8b0b8e4124f7499fc07 ] Currently, when hb_interval is changed by users, it won't take effect until the next expiry of hb timer. As the default value is 30s, users have to wait up to 30s to wait its hb_interval update to work. This becomes pretty bad in containers where a much smaller value is usually set on hb_interval. This patch improves it by resetting the hb timer immediately once the value of hb_interval is updated by users. Note that we don't address the already existing 'problem' when sending a heartbeat 'on demand' if one hb has just been sent(from the timer) mentioned in: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg590224.html Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://lore.kernel.org/r/75465785f8ee5df2fb3acdca9b8fafdc18984098.1696172660.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-10sctp: update transport state when processing a dupcook packetXin Long
[ Upstream commit 2222a78075f0c19ca18db53fd6623afb4aff602d ] During the 4-way handshake, the transport's state is set to ACTIVE in sctp_process_init() when processing INIT_ACK chunk on client or COOKIE_ECHO chunk on server. In the collision scenario below: 192.168.1.2 > 192.168.1.1: sctp (1) [INIT] [init tag: 3922216408] 192.168.1.1 > 192.168.1.2: sctp (1) [INIT] [init tag: 144230885] 192.168.1.2 > 192.168.1.1: sctp (1) [INIT ACK] [init tag: 3922216408] 192.168.1.1 > 192.168.1.2: sctp (1) [COOKIE ECHO] 192.168.1.2 > 192.168.1.1: sctp (1) [COOKIE ACK] 192.168.1.1 > 192.168.1.2: sctp (1) [INIT ACK] [init tag: 3914796021] when processing COOKIE_ECHO on 192.168.1.2, as it's in COOKIE_WAIT state, sctp_sf_do_dupcook_b() is called by sctp_sf_do_5_2_4_dupcook() where it creates a new association and sets its transport to ACTIVE then updates to the old association in sctp_assoc_update(). However, in sctp_assoc_update(), it will skip the transport update if it finds a transport with the same ipaddr already existing in the old asoc, and this causes the old asoc's transport state not to move to ACTIVE after the handshake. This means if DATA retransmission happens at this moment, it won't be able to enter PF state because of the check 'transport->state == SCTP_ACTIVE' in sctp_do_8_2_transport_strike(). This patch fixes it by updating the transport in sctp_assoc_update() with sctp_assoc_add_peer() where it updates the transport state if there is already a transport with the same ipaddr exists in the old asoc. Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://lore.kernel.org/r/fd17356abe49713ded425250cc1ae51e9f5846c6.1696172325.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23sctp: annotate data-races around sk->sk_wmem_queuedEric Dumazet
[ Upstream commit dc9511dd6f37fe803f6b15b61b030728d7057417 ] sk->sk_wmem_queued can be read locklessly from sctp_poll() Use sk_wmem_queued_add() when the field is changed, and add READ_ONCE() annotations in sctp_writeable() and sctp_assocs_seq_show() syzbot reported: BUG: KCSAN: data-race in sctp_poll / sctp_wfree read-write to 0xffff888149d77810 of 4 bytes by interrupt on cpu 0: sctp_wfree+0x170/0x4a0 net/sctp/socket.c:9147 skb_release_head_state+0xb7/0x1a0 net/core/skbuff.c:988 skb_release_all net/core/skbuff.c:1000 [inline] __kfree_skb+0x16/0x140 net/core/skbuff.c:1016 consume_skb+0x57/0x180 net/core/skbuff.c:1232 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1503 [inline] sctp_chunk_put+0xcd/0x130 net/sctp/sm_make_chunk.c:1530 sctp_datamsg_put+0x29a/0x300 net/sctp/chunk.c:128 sctp_chunk_free+0x34/0x50 net/sctp/sm_make_chunk.c:1515 sctp_outq_sack+0xafa/0xd70 net/sctp/outqueue.c:1381 sctp_cmd_process_sack net/sctp/sm_sideeffect.c:834 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1366 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline] sctp_do_sm+0x12c7/0x31b0 net/sctp/sm_sideeffect.c:1169 sctp_assoc_bh_rcv+0x2b2/0x430 net/sctp/associola.c:1051 sctp_inq_push+0x108/0x120 net/sctp/inqueue.c:80 sctp_rcv+0x116e/0x1340 net/sctp/input.c:243 sctp6_rcv+0x25/0x40 net/sctp/ipv6.c:1120 ip6_protocol_deliver_rcu+0x92f/0xf30 net/ipv6/ip6_input.c:437 ip6_input_finish net/ipv6/ip6_input.c:482 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ip6_input+0xbd/0x1b0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish+0x1e2/0x2e0 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:303 [inline] ipv6_rcv+0x74/0x150 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core net/core/dev.c:5452 [inline] __netif_receive_skb+0x90/0x1b0 net/core/dev.c:5566 process_backlog+0x21f/0x380 net/core/dev.c:5894 __napi_poll+0x60/0x3b0 net/core/dev.c:6460 napi_poll net/core/dev.c:6527 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6660 __do_softirq+0xc1/0x265 kernel/softirq.c:553 run_ksoftirqd+0x17/0x20 kernel/softirq.c:921 smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164 kthread+0x1d7/0x210 kernel/kthread.c:389 ret_from_fork+0x2e/0x40 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 read to 0xffff888149d77810 of 4 bytes by task 17828 on cpu 1: sctp_writeable net/sctp/socket.c:9304 [inline] sctp_poll+0x265/0x410 net/sctp/socket.c:8671 sock_poll+0x253/0x270 net/socket.c:1374 vfs_poll include/linux/poll.h:88 [inline] do_pollfd fs/select.c:873 [inline] do_poll fs/select.c:921 [inline] do_sys_poll+0x636/0xc00 fs/select.c:1015 __do_sys_ppoll fs/select.c:1121 [inline] __se_sys_ppoll+0x1af/0x1f0 fs/select.c:1101 __x64_sys_ppoll+0x67/0x80 fs/select.c:1101 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00019e80 -> 0x0000cc80 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 17828 Comm: syz-executor.1 Not tainted 6.5.0-rc7-syzkaller-00185-g28f20a19294d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> 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://lore.kernel.org/r/20230830094519.950007-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23sctp: handle invalid error codes without calling BUG()Dan Carpenter
[ Upstream commit a0067dfcd9418fd3b0632bc59210d120d038a9c6 ] The sctp_sf_eat_auth() function is supposed to return enum sctp_disposition values but if the call to sctp_ulpevent_make_authkey() fails, it returns -ENOMEM. This results in calling BUG() inside the sctp_side_effects() function. Calling BUG() is an over reaction and not helpful. Call WARN_ON_ONCE() instead. This code predates git. Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30sock: annotate data-races around prot->memory_pressureEric Dumazet
[ Upstream commit 76f33296d2e09f63118db78125c95ef56df438e9 ] *prot->memory_pressure is read/writen locklessly, we need to add proper annotations. A recent commit added a new race, it is time to audit all accesses. Fixes: 2d0c88e84e48 ("sock: Fix misuse of sk_under_memory_pressure()") Fixes: 4d93df0abd50 ("[SCTP]: Rewrite of sctp buffer management code") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Abel Wu <wuyun.abel@bytedance.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Link: https://lore.kernel.org/r/20230818015132.2699348-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-27sctp: fix potential deadlock on &net->sctp.addr_wq_lockChengfeng Ye
[ Upstream commit 6feb37b3b06e9049e20dcf7e23998f92c9c5be9a ] As &net->sctp.addr_wq_lock is also acquired by the timer sctp_addr_wq_timeout_handler() in protocal.c, the same lock acquisition at sctp_auto_asconf_init() seems should disable irq since it is called from sctp_accept() under process context. Possible deadlock scenario: sctp_accept() -> sctp_sock_migrate() -> sctp_auto_asconf_init() -> spin_lock(&net->sctp.addr_wq_lock) <timer interrupt> -> sctp_addr_wq_timeout_handler() -> spin_lock_bh(&net->sctp.addr_wq_lock); (deadlock here) This flaw was found using an experimental static analysis tool we are developing for irq-related deadlock. The tentative patch fix the potential deadlock by spin_lock_bh(). Signed-off-by: Chengfeng Ye <dg573847474@gmail.com> Fixes: 34e5b0118685 ("sctp: delay auto_asconf init until binding the first addr") Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/20230627120340.19432-1-dg573847474@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-21sctp: fix an error code in sctp_sf_eat_auth()Dan Carpenter
[ Upstream commit 75e6def3b26736e7ff80639810098c9074229737 ] The sctp_sf_eat_auth() function is supposed to enum sctp_disposition values and returning a kernel error code will cause issues in the caller. Change -ENOMEM to SCTP_DISPOSITION_NOMEM. Fixes: 65b07e5d0d09 ("[SCTP]: API updates to suport SCTP-AUTH extensions.") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Acked-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-26sctp: Call inet6_destroy_sock() via sk->sk_destruct().Kuniyuki Iwashima
commit 6431b0f6ff1633ae598667e4cdd93830074a03e8 upstream. After commit d38afeec26ed ("tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct()."), we call inet6_destroy_sock() in sk->sk_destruct() by setting inet6_sock_destruct() to it to make sure we do not leak inet6-specific resources. SCTP sets its own sk->sk_destruct() in the sctp_init_sock(), and SCTPv6 socket reuses it as the init function. To call inet6_sock_destruct() from SCTPv6 sk->sk_destruct(), we set sctp_v6_destruct_sock() in a new init function. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20sctp: fix a potential overflow in sctp_ifwdtsn_skipXin Long
[ Upstream commit 32832a2caf82663870126c5186cf8f86c8b2a649 ] Currently, when traversing ifwdtsn skips with _sctp_walk_ifwdtsn, it only checks the pos against the end of the chunk. However, the data left for the last pos may be < sizeof(struct sctp_ifwdtsn_skip), and dereference it as struct sctp_ifwdtsn_skip may cause coverflow. This patch fixes it by checking the pos against "the end of the chunk - sizeof(struct sctp_ifwdtsn_skip)" in sctp_ifwdtsn_skip, similar to sctp_fwdtsn_skip. Fixes: 0fc2ea922c8a ("sctp: implement validate_ftsn for sctp_stream_interleave") Signed-off-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/2a71bffcd80b4f2c61fac6d344bb2f11c8fd74f7.1681155810.git.lucien.xin@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-20sctp: check send stream number after wait_for_sndbufXin Long
[ Upstream commit 2584024b23552c00d95b50255e47bd18d306d31a ] 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: 5bbbbe32a431 ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11sctp: add a refcnt in sctp_stream_priorities to avoid a nested loopXin Long
[ Upstream commit 68ba44639537de6f91fe32783766322d41848127 ] With this refcnt added in sctp_stream_priorities, we don't need to traverse all streams to check if the prio is used by other streams when freeing one stream's prio in sctp_sched_prio_free_sid(). This can avoid a nested loop (up to 65535 * 65535), which may cause a stuck as Ying reported: watchdog: BUG: soft lockup - CPU#23 stuck for 26s! [ksoftirqd/23:136] Call Trace: <TASK> sctp_sched_prio_free_sid+0xab/0x100 [sctp] sctp_stream_free_ext+0x64/0xa0 [sctp] sctp_stream_free+0x31/0x50 [sctp] sctp_association_free+0xa5/0x200 [sctp] Note that it doesn't need to use refcount_t type for this counter, as its accessing is always protected under the sock lock. v1->v2: - add a check in sctp_sched_prio_set to avoid the possible prio_head refcnt overflow. Fixes: 9ed7bfc79542 ("sctp: fix memory leak in sctp_stream_outq_migrate()") Reported-by: Ying Xu <yinxu@redhat.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/825eb0c905cb864991eba335f4a2b780e543f06b.1677085641.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-22sctp: sctp_sock_filter(): avoid list_entry() on possibly empty listPietro Borrello
commit a1221703a0f75a9d81748c516457e0fc76951496 upstream. Use list_is_first() to check whether tsp->asoc matches the first element of ep->asocs, as the list is not guaranteed to have an entry. Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/20230208-sctp-filter-v2-1-6e1f4017f326@diag.uniroma1.it Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06sctp: fail if no bound addresses can be used for a given scopeMarcelo Ricardo Leitner
[ Upstream commit 458e279f861d3f61796894cd158b780765a1569f ] Currently, if you bind the socket to something like: servaddr.sin6_family = AF_INET6; servaddr.sin6_port = htons(0); servaddr.sin6_scope_id = 0; inet_pton(AF_INET6, "::1", &servaddr.sin6_addr); And then request a connect to: connaddr.sin6_family = AF_INET6; connaddr.sin6_port = htons(20000); connaddr.sin6_scope_id = if_nametoindex("lo"); inet_pton(AF_INET6, "fe88::1", &connaddr.sin6_addr); What the stack does is: - bind the socket - create a new asoc - to handle the connect - copy the addresses that can be used for the given scope - try to connect But the copy returns 0 addresses, and the effect is that it ends up trying to connect as if the socket wasn't bound, which is not the desired behavior. This unexpected behavior also allows KASLR leaks through SCTP diag interface. The fix here then is, if when trying to copy the addresses that can be used for the scope used in connect() it returns 0 addresses, bail out. This is what TCP does with a similar reproducer. Reported-by: Pietro Borrello <borrello@diag.uniroma1.it> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/9fcd182f1099f86c6661f3717f63712ddd1c676c.1674496737.git.marcelo.leitner@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08sctp: fix memory leak in sctp_stream_outq_migrate()Zhengchao Shao
[ Upstream commit 9ed7bfc79542119ac0a9e1ce8a2a5285e43433e9 ] When sctp_stream_outq_migrate() is called to release stream out resources, the memory pointed to by prio_head in stream out is not released. The memory leak information is as follows: unreferenced object 0xffff88801fe79f80 (size 64): comm "sctp_repo", pid 7957, jiffies 4294951704 (age 36.480s) hex dump (first 32 bytes): 80 9f e7 1f 80 88 ff ff 80 9f e7 1f 80 88 ff ff ................ 90 9f e7 1f 80 88 ff ff 90 9f e7 1f 80 88 ff ff ................ backtrace: [<ffffffff81b215c6>] kmalloc_trace+0x26/0x60 [<ffffffff88ae517c>] sctp_sched_prio_set+0x4cc/0x770 [<ffffffff88ad64f2>] sctp_stream_init_ext+0xd2/0x1b0 [<ffffffff88aa2604>] sctp_sendmsg_to_asoc+0x1614/0x1a30 [<ffffffff88ab7ff1>] sctp_sendmsg+0xda1/0x1ef0 [<ffffffff87f765ed>] inet_sendmsg+0x9d/0xe0 [<ffffffff8754b5b3>] sock_sendmsg+0xd3/0x120 [<ffffffff8755446a>] __sys_sendto+0x23a/0x340 [<ffffffff87554651>] __x64_sys_sendto+0xe1/0x1b0 [<ffffffff89978b49>] do_syscall_64+0x39/0xb0 [<ffffffff89a0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Link: https://syzkaller.appspot.com/bug?exrid=29c402e56c4760763cc0 Fixes: 637784ade221 ("sctp: introduce priority based stream scheduler") Reported-by: syzbot+29c402e56c4760763cc0@syzkaller.appspotmail.com Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/20221126031720.378562-1-shaozhengchao@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26sctp: handle the error returned from sctp_auth_asoc_init_active_keyXin Long
[ Upstream commit 022152aaebe116a25c39818a07e175a8cd3c1e11 ] When it returns an error from sctp_auth_asoc_init_active_key(), the active_key is actually not updated. The old sh_key will be freeed while it's still used as active key in asoc. Then an use-after-free will be triggered when sending patckets, as found by syzbot: sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 sctp_set_owner_w net/sctp/socket.c:132 [inline] sctp_sendmsg_to_asoc+0xbd5/0x1a20 net/sctp/socket.c:1863 sctp_sendmsg+0x1053/0x1d50 net/sctp/socket.c:2025 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 This patch is to fix it by not replacing the sh_key when it returns errors from sctp_auth_asoc_init_active_key() in sctp_auth_set_key(). For sctp_auth_set_active_key(), old active_key_id will be set back to asoc->active_key_id when the same thing happens. Fixes: 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced") Reported-by: syzbot+a236dd8e9622ed8954a3@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-03sctp: leave the err path free in sctp_stream_init to sctp_stream_freeXin Long
[ Upstream commit 181d8d2066c000ba0a0e6940a7ad80f1a0e68e9d ] A NULL pointer dereference was reported by Wei Chen: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:__list_del_entry_valid+0x26/0x80 Call Trace: <TASK> sctp_sched_dequeue_common+0x1c/0x90 sctp_sched_prio_dequeue+0x67/0x80 __sctp_outq_teardown+0x299/0x380 sctp_outq_free+0x15/0x20 sctp_association_free+0xc3/0x440 sctp_do_sm+0x1ca7/0x2210 sctp_assoc_bh_rcv+0x1f6/0x340 This happens when calling sctp_sendmsg without connecting to server first. In this case, a data chunk already queues up in send queue of client side when processing the INIT_ACK from server in sctp_process_init() where it calls sctp_stream_init() to alloc stream_in. If it fails to alloc stream_in all stream_out will be freed in sctp_stream_init's err path. Then in the asoc freeing it will crash when dequeuing this data chunk as stream_out is missing. As we can't free stream out before dequeuing all data from send queue, and this patch is to fix it by moving the err path stream_out/in freeing in sctp_stream_init() to sctp_stream_free() which is eventually called when freeing the asoc in sctp_association_free(). This fix also makes the code in sctp_process_init() more clear. Note that in sctp_association_init() when it fails in sctp_stream_init(), sctp_association_free() will not be called, and in that case it should go to 'stream_free' err path to free stream instead of 'fail_init'. Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") Reported-by: Wei Chen <harperchen1110@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/831a3dc100c4908ff76e5bcc363be97f2778bc0b.1658787066.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-03sctp: fix sleep in atomic context bug in timer handlersDuoming Zhou
[ Upstream commit b89fc26f741d9f9efb51cba3e9b241cf1380ec5a ] There are sleep in atomic context bugs in timer handlers of sctp such as sctp_generate_t3_rtx_event(), sctp_generate_probe_event(), sctp_generate_t1_init_event(), sctp_generate_timeout_event(), sctp_generate_t3_rtx_event() and so on. The root cause is sctp_sched_prio_init_sid() with GFP_KERNEL parameter that may sleep could be called by different timer handlers which is in interrupt context. One of the call paths that could trigger bug is shown below: (interrupt context) sctp_generate_probe_event sctp_do_sm sctp_side_effects sctp_cmd_interpreter sctp_outq_teardown sctp_outq_init sctp_sched_set_sched n->init_sid(..,GFP_KERNEL) sctp_sched_prio_init_sid //may sleep This patch changes gfp_t parameter of init_sid in sctp_sched_set_sched() from GFP_KERNEL to GFP_ATOMIC in order to prevent sleep in atomic context bugs. Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Link: https://lore.kernel.org/r/20220723015809.11553-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29ip: Fix data-races around sysctl_ip_nonlocal_bind.Kuniyuki Iwashima
[ Upstream commit 289d3b21fb0bfc94c4e98f10635bba1824e5f83c ] While reading sysctl_ip_nonlocal_bind, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14sctp: read sk->sk_bound_dev_if once in sctp_rcv()Eric Dumazet
[ Upstream commit a20ea298071f46effa3aaf965bf9bb34c901db3f ] sctp_rcv() reads sk->sk_bound_dev_if twice while the socket is not locked. Another cpu could change this field under us. Fixes: 0fd9a65a76e8 ("[SCTP] Support SO_BINDTODEVICE socket option on incoming packets.") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-09sctp: check asoc strreset_chunk in sctp_generate_reconf_eventXin Long
[ Upstream commit 165e3e17fe8fe6a8aab319bc6e631a2e23b9a857 ] 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: 7b9438de0cd4 ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20sctp: Initialize daddr on peeled off socketPetr Malat
[ Upstream commit 8467dda0c26583547731e7f3ea73fc3856bae3bf ] Function sctp_do_peeloff() wrongly initializes daddr of the original socket instead of the peeled off socket, which makes getpeername() return zeroes instead of the primary address. Initialize the new socket instead. Fixes: d570ee490fb1 ("[SCTP]: Correctly set daddr for IPv6 sockets during peeloff") Signed-off-by: Petr Malat <oss@malat.biz> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Link: https://lore.kernel.org/r/20220409063611.673193-1-oss@malat.biz Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-19sctp: fix the processing for INIT chunkXin Long
commit eae5783908042a762c24e1bd11876edb91d314b1 upstream. This patch fixes the problems below: 1. In non-shutdown_ack_sent states: in sctp_sf_do_5_1B_init() and sctp_sf_do_5_2_2_dupinit(): chunk length check should be done before any checks that may cause to send abort, as making packet for abort will access the init_tag from init_hdr in sctp_ootb_pkt_new(). 2. In shutdown_ack_sent state: in sctp_sf_do_9_2_reshutack(): The same checks as does in sctp_sf_do_5_2_2_dupinit() is needed for sctp_sf_do_9_2_reshutack(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-16sctp: fix kernel-infoleak for SCTP socketsEric Dumazet
[ Upstream commit 633593a808980f82d251d0ca89730d8bb8b0220c ] syzbot reported a kernel infoleak [1] of 4 bytes. After analysis, it turned out r->idiag_expires is not initialized if inet_sctp_diag_fill() calls inet_diag_msg_common_fill() Make sure to clear idiag_timer/idiag_retrans/idiag_expires and let inet_diag_msg_sctpasoc_fill() fill them again if needed. [1] BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:154 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 instrument_copy_to_user include/linux/instrumented.h:121 [inline] copyout lib/iov_iter.c:154 [inline] _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 copy_to_iter include/linux/uio.h:162 [inline] simple_copy_to_iter+0xf3/0x140 net/core/datagram.c:519 __skb_datagram_iter+0x2d5/0x11b0 net/core/datagram.c:425 skb_copy_datagram_iter+0xdc/0x270 net/core/datagram.c:533 skb_copy_datagram_msg include/linux/skbuff.h:3696 [inline] netlink_recvmsg+0x669/0x1c80 net/netlink/af_netlink.c:1977 sock_recvmsg_nosec net/socket.c:948 [inline] sock_recvmsg net/socket.c:966 [inline] __sys_recvfrom+0x795/0xa10 net/socket.c:2097 __do_sys_recvfrom net/socket.c:2115 [inline] __se_sys_recvfrom net/socket.c:2111 [inline] __x64_sys_recvfrom+0x19d/0x210 net/socket.c:2111 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3247 [inline] __kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4975 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0x545/0xf90 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1158 [inline] netlink_dump+0x3e5/0x16c0 net/netlink/af_netlink.c:2248 __netlink_dump_start+0xcf8/0xe90 net/netlink/af_netlink.c:2373 netlink_dump_start include/linux/netlink.h:254 [inline] inet_diag_handler_cmd+0x2e7/0x400 net/ipv4/inet_diag.c:1341 sock_diag_rcv_msg+0x24a/0x620 netlink_rcv_skb+0x40c/0x7e0 net/netlink/af_netlink.c:2494 sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x1093/0x1360 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x14d9/0x1720 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] sock_write_iter+0x594/0x690 net/socket.c:1061 do_iter_readv_writev+0xa7f/0xc70 do_iter_write+0x52c/0x1500 fs/read_write.c:851 vfs_writev fs/read_write.c:924 [inline] do_writev+0x645/0xe00 fs/read_write.c:967 __do_sys_writev fs/read_write.c:1040 [inline] __se_sys_writev fs/read_write.c:1037 [inline] __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Bytes 68-71 of 2508 are uninitialized Memory access of size 2508 starts at ffff888114f9b000 Data copied to user address 00007f7fe09ff2e0 CPU: 1 PID: 3478 Comm: syz-executor306 Not tainted 5.17.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/20220310001145.297371-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-05sctp: use call_rcu to free endpointXin Long
[ Upstream commit 5ec7d18d1813a5bead0b495045606c93873aecbb ] This patch is to delay the endpoint free by calling call_rcu() to fix another use-after-free issue in sctp_sock_dump(): BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20 Call Trace: __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] __lock_sock+0x203/0x350 net/core/sock.c:2253 lock_sock_nested+0xfe/0x120 net/core/sock.c:2774 lock_sock include/net/sock.h:1492 [inline] sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:324 sctp_for_each_transport+0x2b5/0x370 net/sctp/socket.c:5091 sctp_diag_dump+0x3ac/0x660 net/sctp/diag.c:527 __inet_diag_dump+0xa8/0x140 net/ipv4/inet_diag.c:1049 inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1065 netlink_dump+0x606/0x1080 net/netlink/af_netlink.c:2244 __netlink_dump_start+0x59a/0x7c0 net/netlink/af_netlink.c:2352 netlink_dump_start include/linux/netlink.h:216 [inline] inet_diag_handler_cmd+0x2ce/0x3f0 net/ipv4/inet_diag.c:1170 __sock_diag_cmd net/core/sock_diag.c:232 [inline] sock_diag_rcv_msg+0x31d/0x410 net/core/sock_diag.c:263 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:274 This issue occurs when asoc is peeled off and the old sk is freed after getting it by asoc->base.sk and before calling lock_sock(sk). To prevent the sk free, as a holder of the sk, ep should be alive when calling lock_sock(). This patch uses call_rcu() and moves sock_put and ep free into sctp_endpoint_destroy_rcu(), so that it's safe to try to hold the ep under rcu_read_lock in sctp_transport_traverse_process(). If sctp_endpoint_hold() returns true, it means this ep is still alive and we have held it and can continue to dump it; If it returns false, it means this ep is dead and can be freed after rcu_read_unlock, and we should skip it. In sctp_sock_dump(), after locking the sk, if this ep is different from tsp->asoc->ep, it means during this dumping, this asoc was peeled off before calling lock_sock(), and the sk should be skipped; If this ep is the same with tsp->asoc->ep, it means no peeloff happens on this asoc, and due to lock_sock, no peeloff will happen either until release_sock. Note that delaying endpoint free won't delay the port release, as the port release happens in sctp_endpoint_destroy() before calling call_rcu(). Also, freeing endpoint by call_rcu() makes it safe to access the sk by asoc->base.sk in sctp_assocs_seq_show() and sctp_rcv(). Thanks Jones to bring this issue up. v1->v2: - improve the changelog. - add kfree(ep) into sctp_endpoint_destroy_rcu(), as Jakub noticed. Reported-by: syzbot+9276d76e83e3bcde6c99@syzkaller.appspotmail.com Reported-by: Lee Jones <lee.jones@linaro.org> Fixes: d25adbeb0cdb ("sctp: fix an use-after-free issue in sctp_sock_dump") Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02sctp: add vtag check in sctp_sf_ootbXin Long
[ Upstream commit 9d02831e517aa36ee6bdb453a0eb47bd49923fe3 ] sctp_sf_ootb() is called when processing DATA chunk in closed state, and many other places are also using it. The vtag in the chunk's sctphdr should be verified, otherwise, as later in chunk length check, it may send abort with the existent asoc's vtag, which can be exploited by one to cook a malicious chunk to terminate a SCTP asoc. When fails to verify the vtag from the chunk, this patch sets asoc to NULL, so that the abort will be made with the vtag from the received chunk later. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02sctp: add vtag check in sctp_sf_do_8_5_1_E_saXin Long
[ Upstream commit ef16b1734f0a176277b7bb9c71a6d977a6ef3998 ] sctp_sf_do_8_5_1_E_sa() is called when processing SHUTDOWN_ACK chunk in cookie_wait and cookie_echoed state. The vtag in the chunk's sctphdr should be verified, otherwise, as later in chunk length check, it may send abort with the existent asoc's vtag, which can be exploited by one to cook a malicious chunk to terminate a SCTP asoc. Note that when fails to verify the vtag from SHUTDOWN-ACK chunk, SHUTDOWN COMPLETE message will still be sent back to peer, but with the vtag from SHUTDOWN-ACK chunk, as said in 5) of rfc4960#section-8.4. While at it, also remove the unnecessary chunk length check from sctp_sf_shut_8_4_5(), as it's already done in both places where it calls sctp_sf_shut_8_4_5(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02sctp: add vtag check in sctp_sf_violationXin Long
[ Upstream commit aa0f697e45286a6b5f0ceca9418acf54b9099d99 ] sctp_sf_violation() is called when processing HEARTBEAT_ACK chunk in cookie_wait state, and some other places are also using it. The vtag in the chunk's sctphdr should be verified, otherwise, as later in chunk length check, it may send abort with the existent asoc's vtag, which can be exploited by one to cook a malicious chunk to terminate a SCTP asoc. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02sctp: fix the processing for COOKIE_ECHO chunkXin Long
[ Upstream commit a64b341b8695e1c744dd972b39868371b4f68f83 ] 1. In closed state: in sctp_sf_do_5_1D_ce(): When asoc is NULL, making packet for abort will use chunk's vtag in sctp_ootb_pkt_new(). But when asoc exists, vtag from the chunk should be verified before using peer.i.init_tag to make packet for abort in sctp_ootb_pkt_new(), and just discard it if vtag is not correct. 2. In the other states: in sctp_sf_do_5_2_4_dupcook(): asoc always exists, but duplicate cookie_echo's vtag will be handled by sctp_tietags_compare() and then take actions, so before that we only verify the vtag for the abort sent for invalid chunk length. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02sctp: fix the processing for INIT_ACK chunkXin Long
[ Upstream commit 438b95a7c98f77d51cbf4db021f41b602d750a3f ] Currently INIT_ACK chunk in non-cookie_echoed state is processed in sctp_sf_discard_chunk() to send an abort with the existent asoc's vtag if the chunk length is not valid. But the vtag in the chunk's sctphdr is not verified, which may be exploited by one to cook a malicious chunk to terminal a SCTP asoc. sctp_sf_discard_chunk() also is called in many other places to send an abort, and most of those have this problem. This patch is to fix it by sending abort with the existent asoc's vtag only if the vtag from the chunk's sctphdr is verified in sctp_sf_discard_chunk(). Note on sctp_sf_do_9_1_abort() and sctp_sf_shutdown_pending_abort(), the chunk length has been verified before sctp_sf_discard_chunk(), so replace it with sctp_sf_discard(). On sctp_sf_do_asconf_ack() and sctp_sf_do_asconf(), move the sctp_chunk_length_valid check ahead of sctp_sf_discard_chunk(), then replace it with sctp_sf_discard(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02sctp: use init_tag from inithdr for ABORT chunkXin Long
[ Upstream commit 4f7019c7eb33967eb87766e0e4602b5576873680 ] Currently Linux SCTP uses the verification tag of the existing SCTP asoc when failing to process and sending the packet with the ABORT chunk. This will result in the peer accepting the ABORT chunk and removing the SCTP asoc. One could exploit this to terminate a SCTP asoc. This patch is to fix it by always using the initiate tag of the received INIT chunk for the ABORT chunk to be sent. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-20sctp: account stream padding length for reconf chunkEiichi Tsukata
commit a2d859e3fc97e79d907761550dbc03ff1b36479c upstream. sctp_make_strreset_req() makes repeated calls to sctp_addto_chunk() which will automatically account for padding on each call. inreq and outreq are already 4 bytes aligned, but the payload is not and doing SCTP_PAD4(a + b) (which _sctp_make_chunk() did implicitly here) is different from SCTP_PAD4(a) + SCTP_PAD4(b) and not enough. It led to possible attempt to use more buffer than it was allocated and triggered a BUG_ON. Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Greg KH <gregkh@linuxfoundation.org> Fixes: cc16f00f6529 ("sctp: add support for generating stream reconf ssn reset request chunk") Reported-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com> Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/b97c1f8b0c7ff79ac4ed206fc2c49d3612e0850c.1634156849.git.mleitner@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootbXin Long
[ Upstream commit f7e745f8e94492a8ac0b0a26e25f2b19d342918f ] We should always check if skb_header_pointer's return is NULL before using it, otherwise it may cause null-ptr-deref, as syzbot reported: KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:sctp_rcv_ootb net/sctp/input.c:705 [inline] RIP: 0010:sctp_rcv+0x1d84/0x3220 net/sctp/input.c:196 Call Trace: <IRQ> sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109 ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422 ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472 dst_input include/net/dst.h:460 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297 Fixes: 3acb50c18d8d ("sctp: delay as much as possible skb_linearize") Reported-by: syzbot+581aff2ae6b860625116@syzkaller.appspotmail.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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26sctp: add param size validation for SCTP_PARAM_SET_PRIMARYMarcelo Ricardo Leitner
commit ef6c8d6ccf0c1dccdda092ebe8782777cd7803c9 upstream. When SCTP handles an INIT chunk, it calls for example: sctp_sf_do_5_1B_init sctp_verify_init sctp_verify_param sctp_process_init sctp_process_param handling of SCTP_PARAM_SET_PRIMARY sctp_verify_init() wasn't doing proper size validation and neither the later handling, allowing it to work over the chunk itself, possibly being uninitialized memory. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-26sctp: validate chunk size in __rcv_asconf_lookupMarcelo Ricardo Leitner
commit b6ffe7671b24689c09faa5675dd58f93758a97ae upstream. In one of the fallbacks that SCTP has for identifying an association for an incoming packet, it looks for AddIp chunk (from ASCONF) and take a peek. Thing is, at this stage nothing was validating that the chunk actually had enough content for that, allowing the peek to happen over uninitialized memory. Similar check already exists in actual asconf handling in sctp_verify_asconf(). Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-12sctp: move the active_key update after sh_keys is addedXin Long
[ Upstream commit ae954bbc451d267f7d60d7b49db811d5a68ebd7b ] In commit 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced"), sctp_auth_asoc_init_active_key() is called to update the active_key right after the old key is deleted and before the new key is added, and it caused that the active_key could be found with the key_id. In Ying Xu's testing, the BUG_ON in sctp_auth_asoc_init_active_key() was triggered: [ ] kernel BUG at net/sctp/auth.c:416! [ ] RIP: 0010:sctp_auth_asoc_init_active_key.part.8+0xe7/0xf0 [sctp] [ ] Call Trace: [ ] sctp_auth_set_key+0x16d/0x1b0 [sctp] [ ] sctp_setsockopt.part.33+0x1ba9/0x2bd0 [sctp] [ ] __sys_setsockopt+0xd6/0x1d0 [ ] __x64_sys_setsockopt+0x20/0x30 [ ] do_syscall_64+0x5b/0x1a0 So fix it by moving the active_key update after sh_keys is added. Fixes: 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced") Reported-by: Ying Xu <yinxu@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-04sctp: fix return value check in __sctp_rcv_asconf_lookupMarcelo Ricardo Leitner
[ Upstream commit 557fb5862c9272ad9b21407afe1da8acfd9b53eb ] As Ben Hutchings noticed, this check should have been inverted: the call returns true in case of success. Reported-by: Ben Hutchings <ben@decadent.org.uk> Fixes: 0c5dc070ff3d ("sctp: validate from_addr_param return") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-31sctp: move 198 addresses from unusable to private scopeXin Long
[ Upstream commit 1d11fa231cabeae09a95cb3e4cf1d9dd34e00f08 ] The doc draft-stewart-tsvwg-sctp-ipv4-00 that restricts 198 addresses was never published. These addresses as private addresses should be allowed to use in SCTP. As Michael Tuexen suggested, this patch is to move 198 addresses from unusable to private scope. Reported-by: Sérgio <surkamp@gmail.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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28sctp: update active_key for asoc when old key is being replacedXin Long
[ Upstream commit 58acd10092268831e49de279446c314727101292 ] syzbot reported a call trace: BUG: KASAN: use-after-free in sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 Call Trace: sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 sctp_set_owner_w net/sctp/socket.c:131 [inline] sctp_sendmsg_to_asoc+0x152e/0x2180 net/sctp/socket.c:1865 sctp_sendmsg+0x103b/0x1d30 net/sctp/socket.c:2027 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:723 This is an use-after-free issue caused by not updating asoc->shkey after it was replaced in the key list asoc->endpoint_shared_keys, and the old key was freed. This patch is to fix by also updating active_key for asoc when old key is being replaced with a new one. Note that this issue doesn't exist in sctp_auth_del_key_id(), as it's not allowed to delete the active_key from the asoc. Fixes: 1b1e0bc99474 ("sctp: add refcnt support for sh_key") Reported-by: syzbot+b774577370208727d12b@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19sctp: add size validation when walking chunksMarcelo Ricardo Leitner
[ Upstream commit 50619dbf8db77e98d821d615af4f634d08e22698 ] The first chunk in a packet is ensured to be present at the beginning of sctp_rcv(), as a packet needs to have at least 1 chunk. But the second one, may not be completely available and ch->length can be over uninitialized memory. Fix here is by only trying to walk on the next chunk if there is enough to hold at least the header, and then proceed with the ch->length validation that is already there. Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19sctp: validate from_addr_param returnMarcelo Ricardo Leitner
[ Upstream commit 0c5dc070ff3d6246d22ddd931f23a6266249e3db ] Ilja reported that, simply putting it, nothing was validating that from_addr_param functions were operating on initialized memory. That is, the parameter itself was being validated by sctp_walk_params, but it doesn't check for types and their specific sizes and it could be a 0-length one, causing from_addr_param to potentially work over the next parameter or even uninitialized memory. The fix here is to, in all calls to from_addr_param, check if enough space is there for the wanted IP address type. Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19sctp: fix a SCTP_MIB_CURRESTAB leak in sctp_sf_do_dupcook_bXin Long
[ Upstream commit f282df0391267fb2b263da1cc3233aa6fb81defc ] Normally SCTP_MIB_CURRESTAB is always incremented once asoc enter into ESTABLISHED from the state < ESTABLISHED and decremented when the asoc is being deleted. However, in sctp_sf_do_dupcook_b(), the asoc's state can be changed to ESTABLISHED from the state >= ESTABLISHED where it shouldn't increment SCTP_MIB_CURRESTAB. Otherwise, one asoc may increment MIB_CURRESTAB multiple times but only decrement once at the end. I was able to reproduce it by using scapy to do the 4-way shakehands, after that I replayed the COOKIE-ECHO chunk with 'peer_vtag' field changed to different values, and SCTP_MIB_CURRESTAB was incremented multiple times and never went back to 0 even when the asoc was freed. This patch is to fix it by only incrementing SCTP_MIB_CURRESTAB when the state < ESTABLISHED in sctp_sf_do_dupcook_b(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19sctp: do asoc update earlier in sctp_sf_do_dupcook_aXin Long
[ Upstream commit 35b4f24415c854cd718ccdf38dbea6297f010aae ] There's a panic that occurs in a few of envs, the call trace is as below: [] general protection fault, ... 0x29acd70f1000a: 0000 [#1] SMP PTI [] RIP: 0010:sctp_ulpevent_notify_peer_addr_change+0x4b/0x1fa [sctp] [] sctp_assoc_control_transport+0x1b9/0x210 [sctp] [] sctp_do_8_2_transport_strike.isra.16+0x15c/0x220 [sctp] [] sctp_cmd_interpreter.isra.21+0x1231/0x1a10 [sctp] [] sctp_do_sm+0xc3/0x2a0 [sctp] [] sctp_generate_timeout_event+0x81/0xf0 [sctp] This is caused by a transport use-after-free issue. When processing a duplicate COOKIE-ECHO chunk in sctp_sf_do_dupcook_a(), both COOKIE-ACK and SHUTDOWN chunks are allocated with the transort from the new asoc. However, later in the sideeffect machine, the old asoc is used to send them out and old asoc's shutdown_last_sent_to is set to the transport that SHUTDOWN chunk attached to in sctp_cmd_setup_t2(), which actually belongs to the new asoc. After the new_asoc is freed and the old asoc T2 timeout, the old asoc's shutdown_last_sent_to that is already freed would be accessed in sctp_sf_t2_timer_expire(). Thanks Alexander and Jere for helping dig into this issue. To fix it, this patch is to do the asoc update first, then allocate the COOKIE-ACK and SHUTDOWN chunks with the 'updated' old asoc. This would make more sense, as a chunk from an asoc shouldn't be sent out with another asoc. We had fixed quite a few issues caused by this. Fixes: 145cb2f7177d ("sctp: Fix bundling of SHUTDOWN with COOKIE-ACK") Reported-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Reported-by: syzbot+bbe538efd1046586f587@syzkaller.appspotmail.com Reported-by: Michal Tesar <mtesar@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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19sctp: Fix out-of-bounds warning in sctp_process_asconf_param()Gustavo A. R. Silva
[ Upstream commit e5272ad4aab347dde5610c0aedb786219e3ff793 ] Fix the following out-of-bounds warning: net/sctp/sm_make_chunk.c:3150:4: warning: 'memcpy' offset [17, 28] from the object at 'addr' is out of the bounds of referenced subobject 'v4' with type 'struct sockaddr_in' at offset 0 [-Warray-bounds] This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). Link: https://github.com/KSPP/linux/issues/109 Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14sctp: delay auto_asconf init until binding the first addrXin Long
commit 34e5b01186858b36c4d7c87e1a025071e8e2401f upstream. As Or Cohen described: If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock held and sp->do_auto_asconf is true, then an element is removed from the auto_asconf_splist without any proper locking. This can happen in the following functions: 1. In sctp_accept, if sctp_sock_migrate fails. 2. In inet_create or inet6_create, if there is a bpf program attached to BPF_CGROUP_INET_SOCK_CREATE which denies creation of the sctp socket. This patch is to fix it by moving the auto_asconf init out of sctp_init_sock(), by which inet_create()/inet6_create() won't need to operate it in sctp_destroy_sock() when calling sk_common_release(). It also makes more sense to do auto_asconf init while binding the first addr, as auto_asconf actually requires an ANY addr bind, see it in sctp_addr_wq_timeout_handler(). This addresses CVE-2021-23133. Fixes: 610236587600 ("bpf: Add new cgroup attach type to enable sock modifications") Reported-by: Or Cohen <orcohen@paloaltonetworks.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14Revert "net/sctp: fix race condition in sctp_destroy_sock"Xin Long
commit 01bfe5e8e428b475982a98a46cca5755726f3f7f upstream. This reverts commit b166a20b07382b8bc1dcee2a448715c9c2c81b5b. This one has to be reverted as it introduced a dead lock, as syzbot reported: CPU0 CPU1 ---- ---- lock(&net->sctp.addr_wq_lock); lock(slock-AF_INET6); lock(&net->sctp.addr_wq_lock); lock(slock-AF_INET6); CPU0 is the thread of sctp_addr_wq_timeout_handler(), and CPU1 is that of sctp_close(). The original issue this commit fixed will be fixed in the next patch. Reported-by: syzbot+959223586843e69a2674@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-21net/sctp: fix race condition in sctp_destroy_sockOr Cohen
commit b166a20b07382b8bc1dcee2a448715c9c2c81b5b upstream. If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock held and sp->do_auto_asconf is true, then an element is removed from the auto_asconf_splist without any proper locking. This can happen in the following functions: 1. In sctp_accept, if sctp_sock_migrate fails. 2. In inet_create or inet6_create, if there is a bpf program attached to BPF_CGROUP_INET_SOCK_CREATE which denies creation of the sctp socket. The bug is fixed by acquiring addr_wq_lock in sctp_destroy_sock instead of sctp_close. This addresses CVE-2021-23133. Reported-by: Or Cohen <orcohen@paloaltonetworks.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Fixes: 610236587600 ("bpf: Add new cgroup attach type to enable sock modifications") Signed-off-by: Or Cohen <orcohen@paloaltonetworks.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14net-ipv6: bugfix - raw & sctp - switch to ipv6_can_nonlocal_bind()Maciej Żenczykowski
commit 630e4576f83accf90366686f39808d665d8dbecc upstream. Found by virtue of ipv6 raw sockets not honouring the per-socket IP{,V6}_FREEBIND setting. Based on hits found via: git grep '[.]ip_nonlocal_bind' We fix both raw ipv6 sockets to honour IP{,V6}_FREEBIND and IP{,V6}_TRANSPARENT, and we fix sctp sockets to honour IP{,V6}_TRANSPARENT (they already honoured FREEBIND), and not just the ipv6 'ip_nonlocal_bind' sysctl. The helper is defined as: static inline bool ipv6_can_nonlocal_bind(struct net *net, struct inet_sock *inet) { return net->ipv6.sysctl.ip_nonlocal_bind || inet->freebind || inet->transparent; } so this change only widens the accepted opt-outs and is thus a clean bugfix. I'm not entirely sure what 'fixes' tag to add, since this is AFAICT an ancient bug, but IMHO this should be applied to stable kernels as far back as possible. As such I'm adding a 'fixes' tag with the commit that originally added the helper, which happened in 4.19. Backporting to older LTS kernels (at least 4.9 and 4.14) would presumably require open-coding it or backporting the helper as well. Other possibly relevant commits: v4.18-rc6-1502-g83ba4645152d net: add helpers checking if socket can be bound to nonlocal address v4.18-rc6-1431-gd0c1f01138c4 net/ipv6: allow any source address for sendmsg pktinfo with ip_nonlocal_bind v4.14-rc5-271-gb71d21c274ef sctp: full support for ipv6 ip_nonlocal_bind & IP_FREEBIND v4.7-rc7-1883-g9b9742022888 sctp: support ipv6 nonlocal bind v4.1-12247-g35a256fee52c ipv6: Nonlocal bind Cc: Lorenzo Colitti <lorenzo@google.com> Fixes: 83ba4645152d ("net: add helpers checking if socket can be bound to nonlocal address") Signed-off-by: Maciej Żenczykowski <maze@google.com> Reviewed-By: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-17net: fix iteration for sctp transport seq_filesNeilBrown
commit af8085f3a4712c57d0dd415ad543bac85780375c upstream. The sctp transport seq_file iterators take a reference to the transport in the ->start and ->next functions and releases the reference in the ->show function. The preferred handling for such resources is to release them in the subsequent ->next or ->stop function call. Since Commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") there is no guarantee that ->show will be called after ->next, so this function can now leak references. So move the sctp_transport_put() call to ->next and ->stop. Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") Reported-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-23net, sctp, filter: remap copy_from_user failure errorDaniel Borkmann
[ no upstream commit ] Fix a potential kernel address leakage for the prerequisite where there is a BPF program attached to the cgroup/setsockopt hook. The latter can only be attached under root, however, if the attached program returns 1 to then run the related kernel handler, an unprivileged program could probe for kernel addresses that way. The reason this is possible is that we're under set_fs(KERNEL_DS) when running the kernel setsockopt handler. Aside from old cBPF there is also SCTP's struct sctp_getaddrs_old which contains pointers in the uapi struct that further need copy_from_user() inside the handler. In the normal case this would just return -EFAULT, but under a temporary KERNEL_DS setting the memory would be copied and we'd end up at a different error code, that is, -EINVAL, for both cases given subsequent validations fail, which then allows the app to distinguish and make use of this fact for probing the address space. In case of later kernel versions this issue won't work anymore thanks to Christoph Hellwig's work that got rid of the various temporary set_fs() address space overrides altogether. One potential option for 5.4 as the only affected stable kernel with the least complexity would be to remap those affected -EFAULT copy_from_user() error codes with -EINVAL such that they cannot be probed anymore. Risk of breakage should be rather low for this particular error case. Fixes: 0d01da6afc54 ("bpf: implement getsockopt and setsockopt hooks") Reported-by: Ryota Shiga (Flatt Security) Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Stanislav Fomichev <sdf@google.com> Cc: Eric Dumazet <edumazet@google.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24sctp: change to hold/put transport for proto_unreach_timerXin Long
[ Upstream commit 057a10fa1f73d745c8e69aa54ab147715f5630ae ] 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: 50b5d6ad6382 ("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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>