======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.279/5830 is trying to acquire lock:
ffff0000d9328a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:4044 [inline]
ffff0000d9328a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4298 [inline]
ffff0000d9328a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x580/0xa18 kernel/workqueue.c:4330

but task is already holding lock:
ffff0000d9328ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x1d8/0x510 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+0x58/0x110 net/core/sock.c:3783
       smc_listen_out+0x104/0x3a0 net/smc/af_smc.c:1933
       smc_listen_work+0x410/0xe88 net/smc/af_smc.c:-1
       process_one_work kernel/workqueue.c:3314 [inline]
       process_scheduled_works+0x79c/0x1098 kernel/workqueue.c:3397
       worker_thread+0x754/0xba0 kernel/workqueue.c:3478
       kthread+0x2f8/0x3c8 kernel/kthread.c:436
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:842

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x1780/0x2f44 kernel/locking/lockdep.c:5237
       lock_acquire+0x140/0x368 kernel/locking/lockdep.c:5868
       touch_work_lockdep_map kernel/workqueue.c:4044 [inline]
       start_flush_work kernel/workqueue.c:4298 [inline]
       __flush_work+0x588/0xa18 kernel/workqueue.c:4330
       __cancel_work_sync+0xc8/0x144 kernel/workqueue.c:4486
       cancel_work_sync+0x24/0x38 kernel/workqueue.c:4523
       smc_clcsock_release+0x64/0xe8 net/smc/smc_close.c:29
       __smc_release+0x510/0x694 net/smc/af_smc.c:316
       smc_close_non_accepted+0xd8/0x254 net/smc/af_smc.c:1864
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0x808/0x9f4 net/smc/smc_close.c:225
       __smc_release+0x90/0x694 net/smc/af_smc.c:292
       smc_release+0x248/0x510 net/smc/af_smc.c:359
       __sock_release+0xa0/0x1d4 net/socket.c:722
       sock_close+0x24/0x38 net/socket.c:1514
       __fput+0x340/0x744 fs/file_table.c:510
       ____fput+0x20/0x30 fs/file_table.c:538
       task_work_run+0x1c4/0x254 kernel/task_work.c:233
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
       exit_to_user_mode_loop+0x10c/0x17c kernel/entry/common.c:98
       __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
       syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
       arm64_syscall_exit_to_user_mode arch/arm64/kernel/entry-common.c:88 [inline]
       el0_svc+0x18c/0x260 arch/arm64/kernel/entry-common.c:741
       el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594

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 ***

3 locks held by syz.3.279/5830:
 #0: ffff0000dc738e40 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff0000dc738e40 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x7c/0x1d4 net/socket.c:721
 #1: ffff0000d9328ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x1d8/0x510 net/smc/af_smc.c:-1
 #2: ffff800088ad72a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #2: ffff800088ad72a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffff800088ad72a0 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4272 [inline]
 #2: ffff800088ad72a0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x108/0xa18 kernel/workqueue.c:4330

stack backtrace:
CPU: 1 UID: 0 PID: 5830 Comm: syz.3.279 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 print_circular_bug+0x328/0x330 kernel/locking/lockdep.c:2043
 check_noncircular+0x158/0x174 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x1780/0x2f44 kernel/locking/lockdep.c:5237
 lock_acquire+0x140/0x368 kernel/locking/lockdep.c:5868
 touch_work_lockdep_map kernel/workqueue.c:4044 [inline]
 start_flush_work kernel/workqueue.c:4298 [inline]
 __flush_work+0x588/0xa18 kernel/workqueue.c:4330
 __cancel_work_sync+0xc8/0x144 kernel/workqueue.c:4486
 cancel_work_sync+0x24/0x38 kernel/workqueue.c:4523
 smc_clcsock_release+0x64/0xe8 net/smc/smc_close.c:29
 __smc_release+0x510/0x694 net/smc/af_smc.c:316
 smc_close_non_accepted+0xd8/0x254 net/smc/af_smc.c:1864
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0x808/0x9f4 net/smc/smc_close.c:225
 __smc_release+0x90/0x694 net/smc/af_smc.c:292
 smc_release+0x248/0x510 net/smc/af_smc.c:359
 __sock_release+0xa0/0x1d4 net/socket.c:722
 sock_close+0x24/0x38 net/socket.c:1514
 __fput+0x340/0x744 fs/file_table.c:510
 ____fput+0x20/0x30 fs/file_table.c:538
 task_work_run+0x1c4/0x254 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x10c/0x17c kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 arm64_syscall_exit_to_user_mode arch/arm64/kernel/entry-common.c:88 [inline]
 el0_svc+0x18c/0x260 arch/arm64/kernel/entry-common.c:741
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594