============================================ WARNING: possible recursive locking detected 5.15.153-syzkaller #0 Not tainted -------------------------------------------- kworker/u5:0/146 is trying to acquire lock: ffff88805d3fc938 ((wq_completion)hci1){+.+.}-{0:0}, at: flush_workqueue+0x154/0x1610 kernel/workqueue.c:2830 but task is already holding lock: ffff88805d3fc938 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((wq_completion)hci1); lock((wq_completion)hci1); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by kworker/u5:0/146: #0: ffff88805d3fc938 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000135fd20 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 stack backtrace: CPU: 1 PID: 146 Comm: kworker/u5:0 Not tainted 5.15.153-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: hci1 hci_error_reset 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:2946 [inline] check_deadlock kernel/locking/lockdep.c:2989 [inline] validate_chain+0x46d2/0x5930 kernel/locking/lockdep.c:3775 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 flush_workqueue+0x170/0x1610 kernel/workqueue.c:2830 drain_workqueue+0xc5/0x390 kernel/workqueue.c:2995 destroy_workqueue+0x7b/0xae0 kernel/workqueue.c:4439 hci_release_dev+0x165/0x1620 net/bluetooth/hci_core.c:4071 bt_host_release+0x7f/0x90 net/bluetooth/hci_sysfs.c:92 device_release+0x91/0x1c0 kobject_cleanup lib/kobject.c:713 [inline] kobject_release lib/kobject.c:744 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x224/0x460 lib/kobject.c:761 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298