======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.195/5281 is trying to acquire lock:
ffff88807c571458 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x109/0xac0 kernel/workqueue.c:3072

but task is already holding lock:
ffff88807cc38130 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x249/0x520 net/smc/af_smc.c:-1

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}:
       lock_sock_nested+0x44/0x100 net/core/sock.c:3504
       smc_listen_out+0xd4/0x3c0 net/smc/af_smc.c:1879
       smc_listen_out_connected net/smc/af_smc.c:1901 [inline]
       smc_listen_decline net/smc/af_smc.c:1936 [inline]
       smc_listen_work+0x57c/0xd60 net/smc/af_smc.c:2480
       process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
       worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
       kthread+0x29d/0x330 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3162 [inline]
       check_prevs_add kernel/locking/lockdep.c:3281 [inline]
       validate_chain kernel/locking/lockdep.c:3897 [inline]
       __lock_acquire+0x3a03/0x7ea0 kernel/locking/lockdep.c:5171
       lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790
       __flush_work+0x122/0xac0 kernel/workqueue.c:3072
       __cancel_work_timer+0x3f4/0x560 kernel/workqueue.c:3163
       smc_clcsock_release+0x5c/0xe0 net/smc/smc_close.c:29
       __smc_release+0x644/0x7b0 net/smc/af_smc.c:314
       smc_close_non_accepted+0xd1/0x1f0 net/smc/af_smc.c:1813
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0xae2/0xea0 net/smc/smc_close.c:225
       __smc_release+0x9c/0x7b0 net/smc/af_smc.c:290
       smc_release+0x2c1/0x520 net/smc/af_smc.c:357
       __sock_release net/socket.c:654 [inline]
       sock_close+0xbf/0x210 net/socket.c:1400
       __fput+0x20a/0x8b0 fs/file_table.c:320
       task_work_run+0x1d0/0x260 kernel/task_work.c:203
       exit_task_work include/linux/task_work.h:39 [inline]
       do_exit+0x9d5/0x2570 kernel/exit.c:887
       __do_sys_exit kernel/exit.c:997 [inline]
       __se_sys_exit kernel/exit.c:995 [inline]
       __x64_sys_exit+0x3c/0x40 kernel/exit.c:995
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_SMC/1);
                               lock((work_completion)(&new_smc->smc_listen_work));
                               lock(sk_lock-AF_SMC/1);
  lock((work_completion)(&new_smc->smc_listen_work));

 *** DEADLOCK ***

2 locks held by syz.0.195/5281:
 #0: ffff8880554fb810 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:764 [inline]
 #0: ffff8880554fb810 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
 #0: ffff8880554fb810 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x82/0x210 net/socket.c:1400
 #1: ffff88807cc38130 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x249/0x520 net/smc/af_smc.c:-1

stack backtrace:
CPU: 0 PID: 5281 Comm: syz.0.195 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x2f8/0x400 kernel/locking/lockdep.c:2215
 check_prev_add kernel/locking/lockdep.c:3162 [inline]
 check_prevs_add kernel/locking/lockdep.c:3281 [inline]
 validate_chain kernel/locking/lockdep.c:3897 [inline]
 __lock_acquire+0x3a03/0x7ea0 kernel/locking/lockdep.c:5171
 lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790
 __flush_work+0x122/0xac0 kernel/workqueue.c:3072
 __cancel_work_timer+0x3f4/0x560 kernel/workqueue.c:3163
 smc_clcsock_release+0x5c/0xe0 net/smc/smc_close.c:29
 __smc_release+0x644/0x7b0 net/smc/af_smc.c:314
 smc_close_non_accepted+0xd1/0x1f0 net/smc/af_smc.c:1813
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0xae2/0xea0 net/smc/smc_close.c:225
 __smc_release+0x9c/0x7b0 net/smc/af_smc.c:290
 smc_release+0x2c1/0x520 net/smc/af_smc.c:357
 __sock_release net/socket.c:654 [inline]
 sock_close+0xbf/0x210 net/socket.c:1400
 __fput+0x20a/0x8b0 fs/file_table.c:320
 task_work_run+0x1d0/0x260 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0x9d5/0x2570 kernel/exit.c:887
 __do_sys_exit kernel/exit.c:997 [inline]
 __se_sys_exit kernel/exit.c:995 [inline]
 __x64_sys_exit+0x3c/0x40 kernel/exit.c:995
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fab0339f559
Code: Unable to access opcode bytes at 0x7fab0339f52f.
RSP: 002b:00007fab04299fd8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007fab03626090 RCX: 00007fab0339f559
RDX: 00007fab0429a9c8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fab03436b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fab03626128 R14: 00007fab03626090 R15: 00007ffc8fb6ad38
 </TASK>