syz-executor.0 (3936) used greatest stack depth: 24416 bytes left
syz-executor.0 (3921) used greatest stack depth: 23920 bytes left
======================================================
WARNING: possible circular locking dependency detected
6.2.0-next-20230224 #1 Not tainted
------------------------------------------------------
syz-executor.5/269 is trying to acquire lock:
ffff88800a6b8880 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: __flush_work+0xdd/0xd80
but task is already holding lock:
ffff88800a6b8920 (&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
get_signal+0x23c8/0x2450
arch_do_signal_or_restart+0x79/0x590
exit_to_user_mode_prepare+0x122/0x190
syscall_exit_to_user_mode+0x1d/0x50
do_syscall_64+0x4c/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.5/269:
#0: ffff88800a6b8920 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}, at: hci_cmd_sync_clear+0x45/0x250
stack backtrace:
CPU: 1 PID: 269 Comm: syz-executor.5 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
memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=3941 'syz-executor.0'
do_group_exit+0xd4/0x2a0
get_signal+0x23c8/0x2450
arch_do_signal_or_restart+0x79/0x590
exit_to_user_mode_prepare+0x122/0x190
syscall_exit_to_user_mode+0x1d/0x50
do_syscall_64+0x4c/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7f5fe8e1513a
Code: Unable to access opcode bytes at 0x7f5fe8e15110.
RSP: 002b:00007ffe7695b9d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 00007f5fe8e1513a
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007ffe7695ba0c R09: ffffffffffff0000
R10: 00007f5fe8ef73e8 R11: 0000000000000246 R12: 00007ffe7695ba0c
R13: 00007f5fe8e773b2 R14: 00007f5fe8ef73e8 R15: 00007f5fe8ef73e0
</TASK>
Bluetooth: hci1: Opcode 0x c03 failed: -110
Bluetooth: hci4: Opcode 0x c03 failed: -110
Bluetooth: hci7: Opcode 0x c03 failed: -110
Bluetooth: hci5: Opcode 0x c03 failed: -110
Bluetooth: hci1: Opcode 0x c03 failed: -110
Bluetooth: hci4: Opcode 0x c03 failed: -110
Bluetooth: hci7: Opcode 0x c03 failed: -110
Bluetooth: hci5: Opcode 0x c03 failed: -110