Bluetooth: hci4: Opcode 0x0c03 failed: -110
============================================
WARNING: possible recursive locking detected
6.1.99-syzkaller #0 Not tainted
--------------------------------------------
kworker/u5:1/4231 is trying to acquire lock:
ffff0000d24e8138 ((wq_completion)hci4){+.+.}-{0:0}, at: __flush_workqueue+0x120/0x11c4 kernel/workqueue.c:2812

but task is already holding lock:
ffff0000d24e8138 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265

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

       CPU0
       ----
  lock((wq_completion)hci4);
  lock((wq_completion)hci4);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by kworker/u5:1/4231:
 #0: ffff0000d24e8138 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
 #1: ffff80001dd87c20 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267

stack backtrace:
CPU: 1 PID: 4231 Comm: kworker/u5:1 Not tainted 6.1.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: hci4 hci_error_reset
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 __lock_acquire+0x6310/0x7680 kernel/locking/lockdep.c:5049
 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662
 __flush_workqueue+0x14c/0x11c4 kernel/workqueue.c:2812
 drain_workqueue+0xb8/0x32c kernel/workqueue.c:2977
 destroy_workqueue+0x80/0xa34 kernel/workqueue.c:4423
 hci_release_dev+0x118/0x11cc net/bluetooth/hci_core.c:2771
 bt_host_release+0x70/0x88 net/bluetooth/hci_sysfs.c:92
 device_release+0x8c/0x1ac
 kobject_cleanup lib/kobject.c:681 [inline]
 kobject_release lib/kobject.c:712 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x2a8/0x41c lib/kobject.c:729
 put_device+0x28/0x40 drivers/base/core.c:3797
 hci_dev_put include/net/bluetooth/hci_core.h:1435 [inline]
 hci_error_reset+0x160/0x35c net/bluetooth/hci_core.c:1063
 process_one_work+0x7ac/0x1404 kernel/workqueue.c:2292
 worker_thread+0x8e4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864