===================================== WARNING: bad unlock balance detected! 5.15.108-syzkaller #0 Not tainted ------------------------------------- kworker/u5:4/3631 is trying to release lock (&conn->chan_lock) at: [] l2cap_bredr_sig_cmd+0xb07/0x9fb0 net/bluetooth/l2cap_core.c:5748 but there are no more locks to release! other info that might help us debug this: 2 locks held by kworker/u5:4/3631: #0: ffff88807ca7a138 ((wq_completion)hci1#2){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2279 #1: ffffc9000306fd20 ((work_completion)(&hdev->rx_work) ){+.+.}-{0:0} , at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2281 stack backtrace: CPU: 0 PID: 3631 Comm: kworker/u5:4 Not tainted 5.15.108-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Workqueue: hci1 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_unlock_imbalance_bug+0x248/0x2b0 kernel/locking/lockdep.c:5064 __lock_release kernel/locking/lockdep.c:5301 [inline] lock_release+0x596/0x9a0 kernel/locking/lockdep.c:5642 __mutex_unlock_slowpath+0xde/0x750 kernel/locking/mutex.c:851 l2cap_bredr_sig_cmd+0xb07/0x9fb0 net/bluetooth/l2cap_core.c:5748 l2cap_sig_channel net/bluetooth/l2cap_core.c:6507 [inline] l2cap_recv_frame+0xa53/0x8870 net/bluetooth/l2cap_core.c:7786 hci_acldata_packet net/bluetooth/hci_core.c:4967 [inline] hci_rx_work+0x489/0x7d0 net/bluetooth/hci_core.c:5158 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Bluetooth: hci1: link tx timeout Bluetooth: hci1: killing stalled connection 11:aa:aa:aa:aa:aa Bluetooth: hci1: link tx timeout Bluetooth: hci1: killing stalled connection 11:aa:aa:aa:aa:aa Bluetooth: hci4: link tx timeout Bluetooth: hci4: killing stalled connection 11:aa:aa:aa:aa:aa Bluetooth: hci4: link tx timeout Bluetooth: hci4: killing stalled connection 11:aa:aa:aa:aa:aa Bluetooth: hci4: link tx timeout Bluetooth: hci4: killing stalled connection 11:aa:aa:aa:aa:aa Bluetooth: hci4: link tx timeout Bluetooth: hci4: killing stalled connection 11:aa:aa:aa:aa:aa Bluetooth: hci4: link tx timeout Bluetooth: hci4: killing stalled connection 11:aa:aa:aa:aa:aa Bluetooth: hci4: link tx timeout Bluetooth: hci4: killing stalled connection 11:aa:aa:aa:aa:aa Bluetooth: hci4: link tx timeout Bluetooth: hci4: killing stalled connection 11:aa:aa:aa:aa:aa