===================================== WARNING: bad unlock balance detected! syzkaller #0 Not tainted ------------------------------------- kworker/u5:1/4079 is trying to release lock (&chan->lock) at: [] l2cap_chan_unlock include/net/bluetooth/l2cap.h:860 [inline] [] l2cap_conless_channel net/bluetooth/l2cap_core.c:7793 [inline] [] l2cap_recv_frame+0xeac/0x6740 net/bluetooth/l2cap_core.c:7846 but there are no more locks to release! other info that might help us debug this: 2 locks held by kworker/u5:1/4079: #0: ffff0000dc034138 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001f9c7c00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 stack backtrace: CPU: 0 PID: 4079 Comm: kworker/u5:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026 Workqueue: hci0 hci_rx_work Call trace: dump_backtrace+0x0/0x458 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_unlock_imbalance_bug+0x11c/0x160 kernel/locking/lockdep.c:5065 __lock_release kernel/locking/lockdep.c:5302 [inline] lock_release+0x454/0x8e0 kernel/locking/lockdep.c:5643 __mutex_unlock_slowpath+0xc4/0x5e4 kernel/locking/mutex.c:851 mutex_unlock+0x90/0xec kernel/locking/mutex.c:536 l2cap_chan_unlock include/net/bluetooth/l2cap.h:860 [inline] l2cap_conless_channel net/bluetooth/l2cap_core.c:7793 [inline] l2cap_recv_frame+0xeac/0x6740 net/bluetooth/l2cap_core.c:7846 l2cap_recv_acldata+0x4dc/0x1364 net/bluetooth/l2cap_core.c:8558 hci_acldata_packet net/bluetooth/hci_core.c:4977 [inline] hci_rx_work+0x3a0/0x868 net/bluetooth/hci_core.c:5169 process_one_work+0x79c/0x1138 kernel/workqueue.c:2310 worker_thread+0x8f4/0x1034 kernel/workqueue.c:2457 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:856