======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.24/4521 is trying to acquire lock:
ffff0000dad68918 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0xe4/0x1ec kernel/workqueue.c:3069

but task is already holding lock:
ffff0000d93d0130 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x1e8/0x514 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:3505
       smc_listen_out+0x118/0x3b0 net/smc/af_smc.c:1878
       smc_listen_out_connected net/smc/af_smc.c:1898 [inline]
       smc_listen_decline net/smc/af_smc.c:1933 [inline]
       smc_listen_work+0x480/0xdd0 net/smc/af_smc.c:2476
       process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
       worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
       kthread+0x254/0x2e0 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:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3830 [inline]
       __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063
       lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676
       __flush_work+0x10c/0x1ec kernel/workqueue.c:3072
       __cancel_work_timer+0x2f8/0x450 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+0x56c/0x6c0 net/smc/af_smc.c:312
       smc_close_non_accepted+0xd8/0x254 net/smc/af_smc.c:1811
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0x9c0/0xd58 net/smc/smc_close.c:225
       __smc_release+0x490/0x6c0 net/smc/af_smc.c:288
       smc_release+0x258/0x514 net/smc/af_smc.c:355
       __sock_release net/socket.c:654 [inline]
       sock_close+0xac/0x1ec net/socket.c:1400
       __fput+0x1b4/0x7b0 fs/file_table.c:320
       ____fput+0x20/0x30 fs/file_table.c:348
       task_work_run+0x1f4/0x280 kernel/task_work.c:203
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151
       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]
       el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

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.4.24/4521:
 #0: ffff0000e1478810 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #0: ffff0000e1478810 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
 #0: ffff0000e1478810 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: sock_close+0x74/0x1ec net/socket.c:1400
 #1: ffff0000d93d0130 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x1e8/0x514 net/smc/af_smc.c:-1

stack backtrace:
CPU: 0 PID: 4521 Comm: syz.4.24 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/02/2026
Call trace:
 dump_backtrace+0x1c4/0x1f0 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+0xf4/0x15c 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+0x264/0x2f8 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3830 [inline]
 __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063
 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676
 __flush_work+0x10c/0x1ec kernel/workqueue.c:3072
 __cancel_work_timer+0x2f8/0x450 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+0x56c/0x6c0 net/smc/af_smc.c:312
 smc_close_non_accepted+0xd8/0x254 net/smc/af_smc.c:1811
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0x9c0/0xd58 net/smc/smc_close.c:225
 __smc_release+0x490/0x6c0 net/smc/af_smc.c:288
 smc_release+0x258/0x514 net/smc/af_smc.c:355
 __sock_release net/socket.c:654 [inline]
 sock_close+0xac/0x1ec net/socket.c:1400
 __fput+0x1b4/0x7b0 fs/file_table.c:320
 ____fput+0x20/0x30 fs/file_table.c:348
 task_work_run+0x1f4/0x280 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151
 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]
 el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585