syzbot

=====================================
WARNING: bad unlock balance detected!
syzkaller #0 Not tainted
-------------------------------------
kworker/u5:2/4272 is trying to release lock (&chan->lock) at:
[<ffffffff88d47d59>] l2cap_recv_frame+0xd09/0x7a10 net/bluetooth/l2cap_core.c:-1
but there are no more locks to release!

other info that might help us debug this:
2 locks held by kworker/u5:2/4272:
 #0: ffff8880251cc138 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000353fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285

stack backtrace:
CPU: 0 PID: 4272 Comm: kworker/u5:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 __lock_release kernel/locking/lockdep.c:5302 [inline]
 lock_release+0x52f/0x870 kernel/locking/lockdep.c:5643
 __mutex_unlock_slowpath+0xb3/0x6a0 kernel/locking/mutex.c:851
 l2cap_recv_frame+0xd09/0x7a10 net/bluetooth/l2cap_core.c:-1
 hci_acldata_packet net/bluetooth/hci_core.c:4973 [inline]
 hci_rx_work+0x4a4/0xa10 net/bluetooth/hci_core.c:5165
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457