============================================ WARNING: possible recursive locking detected 5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0 Not tainted -------------------------------------------- kworker/0:5/3665 is trying to acquire lock: ffff8880703d3c18 (&clnt->lock){+.+.}-{2:2}, at: p9_tag_remove net/9p/client.c:367 [inline] ffff8880703d3c18 (&clnt->lock){+.+.}-{2:2}, at: p9_req_put+0x78/0x200 net/9p/client.c:375 but task is already holding lock: ffff8880703d3c18 (&clnt->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff8880703d3c18 (&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/0:5/3665: #0: ffff888012064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262 #1: ffffc90003f6fd00 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264 #2: ffff8880703d3c18 (&clnt->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #2: ffff8880703d3c18 (&clnt->lock){+.+.}-{2:2}, at: p9_conn_cancel+0xfd/0x810 net/9p/trans_fd.c:192 stack backtrace: CPU: 0 PID: 3665 Comm: kworker/0:5 Not tainted 5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Workqueue: events p9_read_work Call Trace: __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_read_work+0x5b5/0x1130 net/9p/trans_fd.c:403 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