Bluetooth: hci4: Opcode 0x0c03 failed: -110 ============================================ WARNING: possible recursive locking detected 6.10.0-rc6-syzkaller-00067-g8a9c6c40432e #0 Not tainted -------------------------------------------- kworker/u9:1/27861 is trying to acquire lock: ffff88807f902148 ((wq_completion)hci4){+.+.}-{0:0}, at: touch_wq_lockdep_map kernel/workqueue.c:3895 [inline] ffff88807f902148 ((wq_completion)hci4){+.+.}-{0:0}, at: __flush_workqueue+0x1b0/0x1710 kernel/workqueue.c:3937 but task is already holding lock: ffff88807f902148 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3223 [inline] ffff88807f902148 ((wq_completion)hci4){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329 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/u9:1/27861: #0: ffff88807f902148 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3223 [inline] #0: ffff88807f902148 ((wq_completion)hci4){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329 #1: ffffc9000cc5fd00 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3224 [inline] #1: ffffc9000cc5fd00 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3329 stack backtrace: CPU: 0 PID: 27861 Comm: kworker/u9:1 Not tainted 6.10.0-rc6-syzkaller-00067-g8a9c6c40432e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: hci4 hci_error_reset Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 touch_wq_lockdep_map kernel/workqueue.c:3895 [inline] __flush_workqueue+0x1c9/0x1710 kernel/workqueue.c:3937 drain_workqueue+0xc9/0x3a0 kernel/workqueue.c:4101 destroy_workqueue+0xba/0xc40 kernel/workqueue.c:5817 hci_release_dev+0x169/0x16b0 net/bluetooth/hci_core.c:2795 bt_host_release+0x83/0x90 net/bluetooth/hci_sysfs.c:94 device_release+0x99/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22f/0x480 lib/kobject.c:737 process_one_work kernel/workqueue.c:3248 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329 worker_thread+0x86d/0xd50 kernel/workqueue.c:3409 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244