============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
kworker/u4:12/4466 is trying to acquire lock:
ffff88801a3ee9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88801a3ee9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: unix_collect_skb+0x15c/0x550 net/unix/garbage.c:413

but task is already holding lock:
ffff88801a3ef1e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88801a3ef1e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: unix_collect_skb+0xb7/0x550 net/unix/garbage.c:405

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(rlock-AF_UNIX);
  lock(rlock-AF_UNIX);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by kworker/u4:12/4466:
 #0: ffff888018479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc90004ab7d00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8ee6cc18 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #2: ffffffff8ee6cc18 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0xcb/0x1100 net/unix/garbage.c:589
 #3: ffff88801a3ef1e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #3: ffff88801a3ef1e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: unix_collect_skb+0xb7/0x550 net/unix/garbage.c:405

stack backtrace:
CPU: 1 PID: 4466 Comm: kworker/u4:12 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
Workqueue: events_unbound __unix_gc
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3090 [inline]
 validate_chain kernel/locking/lockdep.c:3884 [inline]
 __lock_acquire+0x690e/0x7ea0 kernel/locking/lockdep.c:5171
 lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 unix_collect_skb+0x15c/0x550 net/unix/garbage.c:413
 __unix_walk_scc net/unix/garbage.c:520 [inline]
 unix_walk_scc net/unix/garbage.c:551 [inline]
 __unix_gc+0x868/0x1100 net/unix/garbage.c:601
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>