======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.16/4538 is trying to acquire lock:
ffff0000d2451f98 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0xcc/0x1bc kernel/workqueue.c:3069

but task is already holding lock:
ffff0000d2450130 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x1e8/0x51c 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+0x70/0x130 net/core/sock.c:3493
       smc_listen_out+0x114/0x3b0 net/smc/af_smc.c:1865
       smc_listen_out_connected net/smc/af_smc.c:1885 [inline]
       smc_listen_work+0x1d0/0xde0 net/smc/af_smc.c:-1
       process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292
       worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439
       kthread+0x250/0x2d8 kernel/kthread.c:376
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x293c/0x6544 kernel/locking/lockdep.c:5049
       lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662
       __flush_work+0xf4/0x1bc kernel/workqueue.c:3072
       __cancel_work_timer+0x2ec/0x448 kernel/workqueue.c:3163
       cancel_work_sync+0x24/0x38 kernel/workqueue.c:3199
       smc_clcsock_release+0x64/0xe8 net/smc/smc_close.c:29
       __smc_release+0x568/0x6c4 net/smc/af_smc.c:300
       smc_close_non_accepted+0xd8/0x260 net/smc/af_smc.c:1798
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0x954/0xcc8 net/smc/smc_close.c:225
       __smc_release+0x48c/0x6c4 net/smc/af_smc.c:276
       smc_release+0x258/0x51c net/smc/af_smc.c:343
       __sock_release net/socket.c:654 [inline]
       sock_close+0xb4/0x1f8 net/socket.c:1400
       __fput+0x1bc/0x7c0 fs/file_table.c:320
       ____fput+0x20/0x30 fs/file_table.c:348
       task_work_run+0x1ec/0x270 kernel/task_work.c:203
       exit_task_work include/linux/task_work.h:39 [inline]
       do_exit+0x54c/0x19a8 kernel/exit.c:880
       do_group_exit+0x194/0x22c kernel/exit.c:1022
       get_signal+0x11d0/0x1310 kernel/signal.c:2871
       do_signal arch/arm64/kernel/signal.c:1081 [inline]
       do_notify_resume+0x34c/0x2b28 arch/arm64/kernel/signal.c:1134
       prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
       exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
       asm_exit_to_user_mode+0x6c/0x80 arch/arm64/kernel/entry-common.c:149
       ret_from_fork+0x1c/0x20 arch/arm64/kernel/entry.S:850

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.0.16/4538:
 #0: ffff0000f62dca10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #0: ffff0000f62dca10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
 #0: ffff0000f62dca10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x7c/0x1f8 net/socket.c:1400
 #1: ffff0000d2450130 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x1e8/0x51c net/smc/af_smc.c:-1

stack backtrace:
CPU: 1 PID: 4538 Comm: syz.0.16 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048
 check_noncircular+0x240/0x2d4 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x293c/0x6544 kernel/locking/lockdep.c:5049
 lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662
 __flush_work+0xf4/0x1bc kernel/workqueue.c:3072
 __cancel_work_timer+0x2ec/0x448 kernel/workqueue.c:3163
 cancel_work_sync+0x24/0x38 kernel/workqueue.c:3199
 smc_clcsock_release+0x64/0xe8 net/smc/smc_close.c:29
 __smc_release+0x568/0x6c4 net/smc/af_smc.c:300
 smc_close_non_accepted+0xd8/0x260 net/smc/af_smc.c:1798
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0x954/0xcc8 net/smc/smc_close.c:225
 __smc_release+0x48c/0x6c4 net/smc/af_smc.c:276
 smc_release+0x258/0x51c net/smc/af_smc.c:343
 __sock_release net/socket.c:654 [inline]
 sock_close+0xb4/0x1f8 net/socket.c:1400
 __fput+0x1bc/0x7c0 fs/file_table.c:320
 ____fput+0x20/0x30 fs/file_table.c:348
 task_work_run+0x1ec/0x270 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0x54c/0x19a8 kernel/exit.c:880
 do_group_exit+0x194/0x22c kernel/exit.c:1022
 get_signal+0x11d0/0x1310 kernel/signal.c:2871
 do_signal arch/arm64/kernel/signal.c:1081 [inline]
 do_notify_resume+0x34c/0x2b28 arch/arm64/kernel/signal.c:1134
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 asm_exit_to_user_mode+0x6c/0x80 arch/arm64/kernel/entry-common.c:149
 ret_from_fork+0x1c/0x20 arch/arm64/kernel/entry.S:850