Bluetooth: hci0: command 0x0409 tx timeout
Bluetooth: hci3: command 0x0409 tx timeout
Bluetooth: hci6: Opcode 0x c03 failed: -110
======================================================
WARNING: possible circular locking dependency detected
6.2.0-next-20230224 #1 Not tainted
------------------------------------------------------
syz-executor.3/275 is trying to acquire lock:
ffff888014698880 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: __flush_work+0xdd/0xd80

but task is already holding lock:
ffff888014698920 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}, at: hci_cmd_sync_clear+0x45/0x250

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}:
       __mutex_lock+0x133/0x14a0
       hci_cmd_sync_work+0x1e6/0x320
       process_one_work+0xa0f/0x1790
       worker_thread+0x63b/0x1260
       kthread+0x2e9/0x3a0
       ret_from_fork+0x2c/0x50

-> #0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}:
       __lock_acquire+0x2d56/0x6380
       lock_acquire.part.0+0xea/0x320
       __flush_work+0x109/0xd80
       __cancel_work_timer+0x39c/0x4e0
       hci_cmd_sync_clear+0x52/0x250
       hci_unregister_dev+0xf9/0x410
       vhci_release+0x80/0x100
       __fput+0x263/0xa40
       task_work_run+0x174/0x280
       do_exit+0xad8/0x2800
       do_group_exit+0xd4/0x2a0
       __x64_sys_exit_group+0x3e/0x50
       do_syscall_64+0x3f/0x90
       entry_SYSCALL_64_after_hwframe+0x72/0xdc

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&hdev->cmd_sync_work_lock);
                               lock((work_completion)(&hdev->cmd_sync_work));
                               lock(&hdev->cmd_sync_work_lock);
  lock((work_completion)(&hdev->cmd_sync_work));

 *** DEADLOCK ***

1 lock held by syz-executor.3/275:
 #0: ffff888014698920 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}, at: hci_cmd_sync_clear+0x45/0x250

stack backtrace:
CPU: 0 PID: 275 Comm: syz-executor.3 Not tainted 6.2.0-next-20230224 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x91/0xf0
 check_noncircular+0x263/0x2e0
 __lock_acquire+0x2d56/0x6380
 lock_acquire.part.0+0xea/0x320
 __flush_work+0x109/0xd80
 __cancel_work_timer+0x39c/0x4e0
 hci_cmd_sync_clear+0x52/0x250
 hci_unregister_dev+0xf9/0x410
 vhci_release+0x80/0x100
 __fput+0x263/0xa40
 task_work_run+0x174/0x280
 do_exit+0xad8/0x2800
 do_group_exit+0xd4/0x2a0
 __x64_sys_exit_group+0x3e/0x50
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7f2c07d75b19
Code: Unable to access opcode bytes at 0x7f2c07d75aef.
RSP: 002b:00007ffee64c3588 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffee64c3d68 RCX: 00007f2c07d75b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 0000000000000000 R08: 0000000000000026 R09: 00007ffee64c3d68
R10: 0000000000000020 R11: 0000000000000246 R12: 00007f2c07dcf233
R13: 0000000000000002 R14: 0000000000000000 R15: 00000000000000f8
 </TASK>
Bluetooth: hci7: Opcode 0x c03 failed: -110
Bluetooth: hci4: command 0x0409 tx timeout
Bluetooth: hci5: command 0x0409 tx timeout
Bluetooth: hci0: command 0x041b tx timeout
Bluetooth: hci2: command 0x041b tx timeout
Bluetooth: hci1: command 0x041b tx timeout
Bluetooth: hci3: command 0x041b tx timeout
Bluetooth: hci4: command 0x041b tx timeout
Bluetooth: hci5: command 0x041b tx timeout
Bluetooth: hci1: command 0x040f tx timeout
Bluetooth: hci2: command 0x040f tx timeout
Bluetooth: hci0: command 0x040f tx timeout
Bluetooth: hci7: unexpected cc 0x0c03 length: 249 > 1
Bluetooth: hci7: unexpected cc 0x1003 length: 249 > 9
Bluetooth: hci7: unexpected cc 0x1001 length: 249 > 9
Bluetooth: hci7: unexpected cc 0x0c23 length: 249 > 4
Bluetooth: hci7: unexpected cc 0x0c25 length: 249 > 3
Bluetooth: hci7: unexpected cc 0x0c38 length: 249 > 2
Bluetooth: hci3: command 0x040f tx timeout
Bluetooth: hci4: command 0x040f tx timeout
Bluetooth: hci5: command 0x040f tx timeout
Bluetooth: hci6: Opcode 0x c03 failed: -110
Bluetooth: hci7: command 0x0409 tx timeout
Bluetooth: hci2: command 0x0419 tx timeout
Bluetooth: hci1: command 0x0419 tx timeout
Bluetooth: hci0: command 0x0419 tx timeout
Bluetooth: hci3: command 0x0419 tx timeout
Bluetooth: hci4: command 0x0419 tx timeout
Bluetooth: hci5: command 0x0419 tx timeout
Bluetooth: hci7: command 0x041b tx timeout