======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.6.8135/32472 is trying to acquire lock:
ffff888076e79458 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0xfa/0x210 kernel/workqueue.c:3090

but task is already holding lock:
ffff888076e78120 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x251/0x530 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:3259
       smc_listen_out+0x109/0x3d0 net/smc/af_smc.c:1576
       smc_listen_out_connected net/smc/af_smc.c:1596 [inline]
       smc_listen_decline net/smc/af_smc.c:1631 [inline]
       smc_listen_work+0x526/0xd00 net/smc/af_smc.c:2089
       process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
       worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
       kthread+0x436/0x520 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:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       __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+0x661/0x7d0 net/smc/af_smc.c:237
       smc_close_non_accepted+0xd1/0x1f0 net/smc/af_smc.c:1518
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0xb00/0xea0 net/smc/smc_close.c:222
       __smc_release+0x8d/0x7d0 net/smc/af_smc.c:213
       smc_release+0x2ca/0x530 net/smc/af_smc.c:280
       __sock_release net/socket.c:651 [inline]
       sock_close+0xd5/0x240 net/socket.c:1345
       __fput+0x234/0x930 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+0x626/0x20c0 kernel/exit.c:883
       do_group_exit+0x12e/0x300 kernel/exit.c:997
       __do_sys_exit_group kernel/exit.c:1008 [inline]
       __se_sys_exit_group kernel/exit.c:1006 [inline]
       __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
       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.6.8135/32472:
 #0: ffff888074522c10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #0: ffff888074522c10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline]
 #0: ffff888074522c10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345
 #1: ffff888076e78120 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x251/0x530 net/smc/af_smc.c:-1

stack backtrace:
CPU: 0 PID: 32472 Comm: syz.6.8135 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x296/0x330 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 kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 __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+0x661/0x7d0 net/smc/af_smc.c:237
 smc_close_non_accepted+0xd1/0x1f0 net/smc/af_smc.c:1518
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0xb00/0xea0 net/smc/smc_close.c:222
 __smc_release+0x8d/0x7d0 net/smc/af_smc.c:213
 smc_release+0x2ca/0x530 net/smc/af_smc.c:280
 __sock_release net/socket.c:651 [inline]
 sock_close+0xd5/0x240 net/socket.c:1345
 __fput+0x234/0x930 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+0x626/0x20c0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 __do_sys_exit_group kernel/exit.c:1008 [inline]
 __se_sys_exit_group kernel/exit.c:1006 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
 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: 0033:0x7f8512e40dd9
Code: Unable to access opcode bytes at RIP 0x7f8512e40daf.
RSP: 002b:00007ffcabc42bf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007f8512e40dd9
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00000000000000fc R08: 00007ffcabc430a7 R09: 0000000000000007
R10: 00007f85130b9fa0 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f85130ba27c R14: 00007f85130ba278 R15: 00007f85130ba270
 </TASK>