============================================
WARNING: possible recursive locking detected
6.0.0-rc7-syzkaller-00239-gb357fd1c2afc #0 Not tainted
--------------------------------------------
kworker/0:0/7 is trying to acquire lock:
ffff88801e484c18 (&clnt->lock){+.+.}-{2:2}, at: p9_tag_remove net/9p/client.c:367 [inline]
ffff88801e484c18 (&clnt->lock){+.+.}-{2:2}, at: p9_req_put+0x78/0x200 net/9p/client.c:375

but task is already holding lock:
ffff88801e484c18 (&clnt->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
ffff88801e484c18 (&clnt->lock){+.+.}-{2:2}, at: p9_conn_cancel+0xfd/0x810 net/9p/trans_fd.c:192

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

       CPU0
       ----
  lock(&clnt->lock);
  lock(&clnt->lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by kworker/0:0/7:
 #0: ffff888012064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262
 #1: ffffc900000c7d00 (p9_poll_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264
 #2: ffff88801e484c18 (&clnt->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
 #2: ffff88801e484c18 (&clnt->lock){+.+.}-{2:2}, at: p9_conn_cancel+0xfd/0x810 net/9p/trans_fd.c:192

stack backtrace:
CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.0.0-rc7-syzkaller-00239-gb357fd1c2afc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Workqueue: events p9_poll_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline]
 check_deadlock kernel/locking/lockdep.c:3031 [inline]
 validate_chain+0x4897/0x6600 kernel/locking/lockdep.c:3816
 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053
 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5666
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
 p9_tag_remove net/9p/client.c:367 [inline]
 p9_req_put+0x78/0x200 net/9p/client.c:375
 p9_conn_cancel+0x715/0x810 net/9p/trans_fd.c:213
 p9_poll_mux net/9p/trans_fd.c:627 [inline]
 p9_poll_workfn+0x1db/0x5e0 net/9p/trans_fd.c:1147
 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>