syzbot


possible deadlock in tcp_diag_get_aux

Status: auto-obsoleted due to no activity on 2024/10/14 09:51
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+bc70c3c417805c7b8ea4@syzkaller.appspotmail.com
First crash: 264d, last: 261d
Bug presence (2)
Date Name Commit Repro Result
2024/03/02 linux-5.15.y (ToT) 80efc6265290 C [report] possible deadlock in tcp_diag_get_aux
2024/03/02 upstream (ToT) d17468c6f1f4 C Didn't crash
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in tcp_diag_get_aux net C 117 258d 275d 25/28 fixed on 2024/04/02 11:36
linux-6.1 possible deadlock in tcp_diag_get_aux origin:lts-only C inconclusive 4 261d 264d 0/3 upstream: reported C repro on 2024/03/01 15:08
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/10/14 09:25 25m retest repro linux-5.15.y OK log
Fix bisection attempts (4)
Created Duration User Patch Repo Result
2024/09/22 12:01 20m fix candidate upstream error job log
2024/08/03 17:58 1m fix candidate upstream error job log
2024/06/03 12:53 0m fix candidate upstream error job log
2024/03/26 01:45 1m fix candidate upstream error job log

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
5.15.150-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/9362 is trying to acquire lock:
ffff8880396e3420 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
ffff8880396e3420 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_diag_get_aux+0x70a/0x7e0 net/ipv4/tcp_diag.c:137

but task is already holding lock:
ffffc90001373888 (&h->lhash2[i].lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline]
ffffc90001373888 (&h->lhash2[i].lock){+.+.}-{2:2}, at: inet_diag_dump_icsk+0x32c/0x1520 net/ipv4/inet_diag.c:1038

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&h->lhash2[i].lock){+.+.}-{2:2}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:363 [inline]
       __inet_hash+0xe3/0x920 net/ipv4/inet_hashtables.c:606
       inet_csk_listen_start+0x231/0x310 net/ipv4/inet_connection_sock.c:1084
       inet_listen+0x2c9/0x7c0 net/ipv4/af_inet.c:231
       rds_tcp_listen_init+0x3f5/0x590 net/rds/tcp_listen.c:311
       rds_tcp_init_net+0x138/0x310 net/rds/tcp.c:559
       ops_init+0x356/0x600 net/core/net_namespace.c:135
       __register_pernet_operations net/core/net_namespace.c:1147 [inline]
       register_pernet_operations+0x2c7/0x650 net/core/net_namespace.c:1216
       register_pernet_device+0x2f/0x80 net/core/net_namespace.c:1303
       rds_tcp_init+0x5e/0xd0 net/rds/tcp.c:717
       do_one_initcall+0x22b/0x7a0 init/main.c:1299
       do_initcall_level+0x157/0x207 init/main.c:1372
       do_initcalls+0x49/0x86 init/main.c:1388
       kernel_init_freeable+0x425/0x5b5 init/main.c:1612
       kernel_init+0x19/0x290 init/main.c:1503
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

-> #0 (k-sk_lock-AF_INET6){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       lock_sock_fast include/net/sock.h:1700 [inline]
       subflow_get_info+0x156/0xcd0 net/mptcp/diag.c:28
       tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
       tcp_diag_get_aux+0x70a/0x7e0 net/ipv4/tcp_diag.c:137
       inet_sk_diag_fill+0xfb4/0x1cb0 net/ipv4/inet_diag.c:345
       inet_diag_dump_icsk+0x4ef/0x1520 net/ipv4/inet_diag.c:1061
       __inet_diag_dump+0x20e/0x3a0 net/ipv4/inet_diag.c:1179
       inet_diag_dump_compat+0x1bd/0x2d0 net/ipv4/inet_diag.c:1287
       netlink_dump+0x606/0xc40 net/netlink/af_netlink.c:2279
       __netlink_dump_start+0x52f/0x6f0 net/netlink/af_netlink.c:2384
       netlink_dump_start include/linux/netlink.h:258 [inline]
       inet_diag_rcv_msg_compat+0x202/0x4c0 net/ipv4/inet_diag.c:1321
       sock_diag_rcv_msg+0xd5/0x400
       netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2505
       sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:276
       netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
       netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356
       netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924
       sock_sendmsg_nosec net/socket.c:704 [inline]
       __sock_sendmsg net/socket.c:716 [inline]
       ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2431
       ___sys_sendmsg+0x252/0x2e0 net/socket.c:2485
       __sys_sendmsg net/socket.c:2514 [inline]
       __do_sys_sendmsg net/socket.c:2523 [inline]
       __se_sys_sendmsg+0x19a/0x260 net/socket.c:2521
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&h->lhash2[i].lock);
                               lock(k-sk_lock-AF_INET6);
                               lock(&h->lhash2[i].lock);
  lock(k-sk_lock-AF_INET6);

 *** DEADLOCK ***

5 locks held by syz-executor.3/9362:
 #0: ffffffff8d9e5588 (sock_diag_mutex){+.+.}-{3:3}, at: sock_diag_rcv+0x17/0x40 net/core/sock_diag.c:275
 #1: ffffffff8d9e53e8 (sock_diag_table_mutex){+.+.}-{3:3}, at: sock_diag_rcv_msg+0xb8/0x400 net/core/sock_diag.c:255
 #2: ffff88807845f690 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{3:3}, at: netlink_dump+0xd0/0xc40 net/netlink/af_netlink.c:2227
 #3: ffffffff8dac1ac8 (inet_diag_table_mutex){+.+.}-{3:3}, at: inet_diag_lock_handler net/ipv4/inet_diag.c:63 [inline]
 #3: ffffffff8dac1ac8 (inet_diag_table_mutex){+.+.}-{3:3}, at: __inet_diag_dump+0x191/0x3a0 net/ipv4/inet_diag.c:1177
 #4: ffffc90001373888 (&h->lhash2[i].lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline]
 #4: ffffc90001373888 (&h->lhash2[i].lock){+.+.}-{2:2}, at: inet_diag_dump_icsk+0x32c/0x1520 net/ipv4/inet_diag.c:1038

stack backtrace:
CPU: 1 PID: 9362 Comm: syz-executor.3 Not tainted 5.15.150-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 lock_sock_fast include/net/sock.h:1700 [inline]
 subflow_get_info+0x156/0xcd0 net/mptcp/diag.c:28
 tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
 tcp_diag_get_aux+0x70a/0x7e0 net/ipv4/tcp_diag.c:137
 inet_sk_diag_fill+0xfb4/0x1cb0 net/ipv4/inet_diag.c:345
 inet_diag_dump_icsk+0x4ef/0x1520 net/ipv4/inet_diag.c:1061
 __inet_diag_dump+0x20e/0x3a0 net/ipv4/inet_diag.c:1179
 inet_diag_dump_compat+0x1bd/0x2d0 net/ipv4/inet_diag.c:1287
 netlink_dump+0x606/0xc40 net/netlink/af_netlink.c:2279
 __netlink_dump_start+0x52f/0x6f0 net/netlink/af_netlink.c:2384
 netlink_dump_start include/linux/netlink.h:258 [inline]
 inet_diag_rcv_msg_compat+0x202/0x4c0 net/ipv4/inet_diag.c:1321
 sock_diag_rcv_msg+0xd5/0x400
 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2505
 sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:276
 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
 netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356
 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2431
 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2485
 __sys_sendmsg net/socket.c:2514 [inline]
 __do_sys_sendmsg net/socket.c:2523 [inline]
 __se_sys_sendmsg+0x19a/0x260 net/socket.c:2521
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f16bebdcda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f16bd15d0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f16bed0af80 RCX: 00007f16bebdcda9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00007f16bec2947a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f16bed0af80 R15: 00007fff613a46d8
 </TASK>
BUG: sleeping function called from invalid context at net/core/sock.c:3271
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 9362, name: syz-executor.3
INFO: lockdep is turned off.
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 1 PID: 9362 Comm: syz-executor.3 Not tainted 5.15.150-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 ___might_sleep+0x547/0x6a0 kernel/sched/core.c:9626
 __lock_sock_fast+0x2f/0xe0 net/core/sock.c:3271
 lock_sock_fast include/net/sock.h:1702 [inline]
 subflow_get_info+0x162/0xcd0 net/mptcp/diag.c:28
 tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
 tcp_diag_get_aux+0x70a/0x7e0 net/ipv4/tcp_diag.c:137
 inet_sk_diag_fill+0xfb4/0x1cb0 net/ipv4/inet_diag.c:345
 inet_diag_dump_icsk+0x4ef/0x1520 net/ipv4/inet_diag.c:1061
 __inet_diag_dump+0x20e/0x3a0 net/ipv4/inet_diag.c:1179
 inet_diag_dump_compat+0x1bd/0x2d0 net/ipv4/inet_diag.c:1287
 netlink_dump+0x606/0xc40 net/netlink/af_netlink.c:2279
 __netlink_dump_start+0x52f/0x6f0 net/netlink/af_netlink.c:2384
 netlink_dump_start include/linux/netlink.h:258 [inline]
 inet_diag_rcv_msg_compat+0x202/0x4c0 net/ipv4/inet_diag.c:1321
 sock_diag_rcv_msg+0xd5/0x400
 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2505
 sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:276
 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
 netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356
 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2431
 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2485
 __sys_sendmsg net/socket.c:2514 [inline]
 __do_sys_sendmsg net/socket.c:2523 [inline]
 __se_sys_sendmsg+0x19a/0x260 net/socket.c:2521
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f16bebdcda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f16bd15d0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f16bed0af80 RCX: 00007f16bebdcda9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00007f16bec2947a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f16bed0af80 R15: 00007fff613a46d8
 </TASK>

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/04 15:43 linux-5.15.y 80efc6265290 3717835d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in tcp_diag_get_aux
2024/03/04 18:15 linux-5.15.y 80efc6265290 3717835d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in tcp_diag_get_aux
2024/03/04 13:28 linux-5.15.y 80efc6265290 3717835d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in tcp_diag_get_aux
2024/03/02 06:04 linux-5.15.y 80efc6265290 25905f5d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in tcp_diag_get_aux
2024/03/01 22:25 linux-5.15.y 80efc6265290 83acf9e0 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in tcp_diag_get_aux
2024/03/01 19:04 linux-5.15.y 80efc6265290 83acf9e0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in tcp_diag_get_aux
2024/03/01 14:44 linux-5.15.y 80efc6265290 83acf9e0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in tcp_diag_get_aux
* Struck through repros no longer work on HEAD.