======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.99/4560 is trying to acquire lock:
ffff88807e491f98 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0xfa/0x210 kernel/workqueue.c:3090

but task is already holding lock:
ffff88807e490120 (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:3258
       smc_listen_out+0xd4/0x3c0 net/smc/af_smc.c:1580
       smc_listen_out_connected net/smc/af_smc.c:1602 [inline]
       smc_listen_decline net/smc/af_smc.c:1637 [inline]
       smc_listen_work+0x52a/0xd10 net/smc/af_smc.c:2095
       process_one_work+0x867/0xff0 kernel/workqueue.c:2310
       worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
       kthread+0x42e/0x520 kernel/kthread.c:334
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3120 [inline]
       check_prevs_add kernel/locking/lockdep.c:3239 [inline]
       validate_chain kernel/locking/lockdep.c:3855 [inline]
       __lock_acquire+0x38f7/0x7d40 kernel/locking/lockdep.c:5120
       lock_acquire+0x19f/0x400 kernel/locking/lockdep.c:5737
       __flush_work+0x116/0x210 kernel/workqueue.c:3090
       __cancel_work_timer+0x3f4/0x560 kernel/workqueue.c:3181
       smc_clcsock_release+0x5c/0xe0 net/smc/smc_close.c:29
       __smc_release+0x644/0x7b0 net/smc/af_smc.c:241
       smc_close_non_accepted+0xd1/0x1f0 net/smc/af_smc.c:1523
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0xae2/0xea0 net/smc/smc_close.c:222
       __smc_release+0x9c/0x7b0 net/smc/af_smc.c:217
       smc_release+0x2c1/0x520 net/smc/af_smc.c:284
       __sock_release net/socket.c:651 [inline]
       sock_close+0xbf/0x210 net/socket.c:1346
       __fput+0x212/0x8c0 fs/file_table.c:311
       task_work_run+0x125/0x1a0 kernel/task_work.c:188
       exit_task_work include/linux/task_work.h:33 [inline]
       do_exit+0x635/0x2110 kernel/exit.c:890
       do_group_exit+0x12c/0x2f0 kernel/exit.c:1004
       __do_sys_exit_group kernel/exit.c:1015 [inline]
       __se_sys_exit_group kernel/exit.c:1013 [inline]
       __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1013
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

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.4.99/4560:
 #0: ffff8880742c1410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline]
 #0: ffff8880742c1410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline]
 #0: ffff8880742c1410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x82/0x210 net/socket.c:1346
 #1: ffff88807e490120 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x249/0x520 net/smc/af_smc.c:-1

stack backtrace:
CPU: 0 PID: 4560 Comm: syz.4.99 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x400 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3120 [inline]
 check_prevs_add kernel/locking/lockdep.c:3239 [inline]
 validate_chain kernel/locking/lockdep.c:3855 [inline]
 __lock_acquire+0x38f7/0x7d40 kernel/locking/lockdep.c:5120
 lock_acquire+0x19f/0x400 kernel/locking/lockdep.c:5737
 __flush_work+0x116/0x210 kernel/workqueue.c:3090
 __cancel_work_timer+0x3f4/0x560 kernel/workqueue.c:3181
 smc_clcsock_release+0x5c/0xe0 net/smc/smc_close.c:29
 __smc_release+0x644/0x7b0 net/smc/af_smc.c:241
 smc_close_non_accepted+0xd1/0x1f0 net/smc/af_smc.c:1523
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0xae2/0xea0 net/smc/smc_close.c:222
 __smc_release+0x9c/0x7b0 net/smc/af_smc.c:217
 smc_release+0x2c1/0x520 net/smc/af_smc.c:284
 __sock_release net/socket.c:651 [inline]
 sock_close+0xbf/0x210 net/socket.c:1346
 __fput+0x212/0x8c0 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x635/0x2110 kernel/exit.c:890
 do_group_exit+0x12c/0x2f0 kernel/exit.c:1004
 __do_sys_exit_group kernel/exit.c:1015 [inline]
 __se_sys_exit_group kernel/exit.c:1013 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1013
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f3fbaa83159
Code: Unable to access opcode bytes at RIP 0x7f3fbaa8312f.
RSP: 002b:00007fffc15822f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3fbaa83159
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fffc158235c R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000021
R13: 00000000000927c0 R14: 0000000000014d26 R15: 00007fffc15823b0
 </TASK>