Bluetooth: hci4: hardware error 0x00 ====================================================== WARNING: possible circular locking dependency detected 6.1.84-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u5:5/3577 is trying to acquire lock: ffff8880747f0870 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: __flush_work+0xe5/0xad0 kernel/workqueue.c:3072 but task is already holding lock: ffffffff8e3f02e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1805 [inline] ffffffff8e3f02e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2441 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (hci_cb_list_lock){+.+.}-{3:3}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747 hci_connect_cfm include/net/bluetooth/hci_core.h:1790 [inline] hci_remote_features_evt+0x664/0xab0 net/bluetooth/hci_event.c:3778 hci_event_func net/bluetooth/hci_event.c:7514 [inline] hci_event_packet+0xa9d/0x1510 net/bluetooth/hci_event.c:7566 hci_rx_work+0x3cd/0xce0 net/bluetooth/hci_core.c:4130 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 -> #2 (&hdev->lock){+.+.}-{3:3}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747 sco_sock_connect+0x181/0x8f0 net/bluetooth/sco.c:593 __sys_connect_file net/socket.c:2006 [inline] __sys_connect+0x2c9/0x300 net/socket.c:2023 __do_sys_connect net/socket.c:2033 [inline] __se_sys_connect net/socket.c:2030 [inline] __x64_sys_connect+0x76/0x80 net/socket.c:2030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 lock_sock_nested+0x44/0x100 net/core/sock.c:3484 lock_sock include/net/sock.h:1745 [inline] sco_sock_timeout+0xbd/0x230 net/bluetooth/sco.c:97 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 -> #0 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __flush_work+0xfe/0xad0 kernel/workqueue.c:3072 __cancel_work_timer+0x519/0x6a0 kernel/workqueue.c:3163 sco_conn_del+0x205/0x300 net/bluetooth/sco.c:205 hci_disconn_cfm include/net/bluetooth/hci_core.h:1808 [inline] hci_conn_hash_flush+0x10e/0x2a0 net/bluetooth/hci_conn.c:2441 hci_dev_close_sync+0x9a9/0x1020 net/bluetooth/hci_sync.c:5015 hci_dev_do_close net/bluetooth/hci_core.c:554 [inline] hci_error_reset+0x12c/0x3c0 net/bluetooth/hci_core.c:1060 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 other info that might help us debug this: Chain exists of: (work_completion)(&(&conn->timeout_work)->work) --> &hdev->lock --> hci_cb_list_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hci_cb_list_lock); lock(&hdev->lock); lock(hci_cb_list_lock); lock((work_completion)(&(&conn->timeout_work)->work)); *** DEADLOCK *** 5 locks held by kworker/u5:5/3577: #0: ffff888027b4f138 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90003e5fd20 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffff88807d2190b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] #2: ffff88807d2190b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_error_reset+0x124/0x3c0 net/bluetooth/hci_core.c:1060 #3: ffff88807d218078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0x1020 net/bluetooth/hci_sync.c:5002 #4: ffffffff8e3f02e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1805 [inline] #4: ffffffff8e3f02e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2441 stack backtrace: CPU: 0 PID: 3577 Comm: kworker/u5:5 Not tainted 6.1.84-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: hci4 hci_error_reset Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __flush_work+0xfe/0xad0 kernel/workqueue.c:3072 __cancel_work_timer+0x519/0x6a0 kernel/workqueue.c:3163 sco_conn_del+0x205/0x300 net/bluetooth/sco.c:205 hci_disconn_cfm include/net/bluetooth/hci_core.h:1808 [inline] hci_conn_hash_flush+0x10e/0x2a0 net/bluetooth/hci_conn.c:2441 hci_dev_close_sync+0x9a9/0x1020 net/bluetooth/hci_sync.c:5015 hci_dev_do_close net/bluetooth/hci_core.c:554 [inline] hci_error_reset+0x12c/0x3c0 net/bluetooth/hci_core.c:1060 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 Bluetooth: hci4: Opcode 0x0c03 failed: -110