======================================================
WARNING: possible circular locking dependency detected
6.12.0-next-20241128-syzkaller #0 Not tainted
------------------------------------------------------
syz.9.1029/10625 is trying to acquire lock:
ffff88806ffc0950 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
ffff88806ffc0950 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
ffff88806ffc0950 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4137 [inline]
ffff88806ffc0950 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0xe7/0xc50 kernel/workqueue.c:4195

but task is already holding lock:
ffff88807a308258 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x234/0x540

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_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       lock_sock_nested+0x48/0x100 net/core/sock.c:3622
       smc_listen_out+0x113/0x3e0 net/smc/af_smc.c:1905
       process_one_work kernel/workqueue.c:3229 [inline]
       process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
       worker_thread+0x870/0xd30 kernel/workqueue.c:3391
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       touch_work_lockdep_map kernel/workqueue.c:3909 [inline]
       start_flush_work kernel/workqueue.c:4163 [inline]
       __flush_work+0x74e/0xc50 kernel/workqueue.c:4195
       __cancel_work_sync+0xbc/0x110 kernel/workqueue.c:4351
       smc_clcsock_release+0x62/0xf0 net/smc/smc_close.c:29
       __smc_release+0x683/0x800 net/smc/af_smc.c:301
       smc_close_non_accepted+0xd8/0x1f0 net/smc/af_smc.c:1837
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0xadb/0xe90 net/smc/smc_close.c:225
       __smc_release+0xa0/0x800 net/smc/af_smc.c:277
       smc_release+0x2dc/0x540 net/smc/af_smc.c:344
       __sock_release net/socket.c:640 [inline]
       sock_close+0xbc/0x240 net/socket.c:1408
       __fput+0x23c/0xa50 fs/file_table.c:450
       task_work_run+0x24f/0x310 kernel/task_work.c:239
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
       syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
       do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

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.9.1029/10625:
 #0: ffff88805602dc08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
 #0: ffff88805602dc08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:639 [inline]
 #0: ffff88805602dc08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x90/0x240 net/socket.c:1408
 #1: ffff88807a308258 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x234/0x540
 #2: ffffffff8e937b20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #2: ffffffff8e937b20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8e937b20 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4137 [inline]
 #2: ffffffff8e937b20 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xe7/0xc50 kernel/workqueue.c:4195

stack backtrace:
CPU: 0 UID: 0 PID: 10625 Comm: syz.9.1029 Not tainted 6.12.0-next-20241128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 touch_work_lockdep_map kernel/workqueue.c:3909 [inline]
 start_flush_work kernel/workqueue.c:4163 [inline]
 __flush_work+0x74e/0xc50 kernel/workqueue.c:4195
 __cancel_work_sync+0xbc/0x110 kernel/workqueue.c:4351
 smc_clcsock_release+0x62/0xf0 net/smc/smc_close.c:29
 __smc_release+0x683/0x800 net/smc/af_smc.c:301
 smc_close_non_accepted+0xd8/0x1f0 net/smc/af_smc.c:1837
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0xadb/0xe90 net/smc/smc_close.c:225
 __smc_release+0xa0/0x800 net/smc/af_smc.c:277
 smc_release+0x2dc/0x540 net/smc/af_smc.c:344
 __sock_release net/socket.c:640 [inline]
 sock_close+0xbc/0x240 net/socket.c:1408
 __fput+0x23c/0xa50 fs/file_table.c:450
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1e6b980849
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1e6c71f058 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f1e6bb45fa0 RCX: 00007f1e6b980849
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000000
RBP: 00007f1e6b9f3986 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1e6bb45fa0 R15: 00007ffefb311668
 </TASK>