====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc6-syzkaller-ge62252bc55b6 #0 Not tainted ------------------------------------------------------ kworker/0:2/898 is trying to acquire lock: ffff88807ca91130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1697 [inline] ffff88807ca91130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_sock_timeout+0xd1/0x290 net/bluetooth/sco.c:97 but task is already holding lock: ffffc900042e7da8 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}: __flush_work+0x109/0xb60 kernel/workqueue.c:3170 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3261 sco_conn_del+0x1b5/0x2b0 net/bluetooth/sco.c:205 sco_disconn_cfm+0x75/0xb0 net/bluetooth/sco.c:1379 hci_disconn_cfm include/net/bluetooth/hci_core.h:1794 [inline] hci_conn_hash_flush+0x126/0x260 net/bluetooth/hci_conn.c:2440 hci_dev_close_sync+0x5fb/0x1200 net/bluetooth/hci_sync.c:4893 hci_dev_do_close+0x31/0x70 net/bluetooth/hci_core.c:554 hci_unregister_dev+0x1ce/0x580 net/bluetooth/hci_core.c:2702 vhci_release+0x80/0xf0 drivers/bluetooth/hci_vhci.c:568 __fput+0x27c/0xa90 fs/file_table.c:321 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad3/0x2960 kernel/exit.c:869 do_group_exit+0xd4/0x2a0 kernel/exit.c:1019 get_signal+0x2315/0x25b0 kernel/signal.c:2859 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #2 (hci_cb_list_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 hci_connect_cfm include/net/bluetooth/hci_core.h:1776 [inline] hci_remote_features_evt+0x4d8/0xa50 net/bluetooth/hci_event.c:3768 hci_event_func net/bluetooth/hci_event.c:7485 [inline] hci_event_packet+0x956/0xfd0 net/bluetooth/hci_event.c:7537 hci_rx_work+0xaeb/0x1340 net/bluetooth/hci_core.c:4058 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #1 (&hdev->lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 sco_sock_connect+0x1ea/0xa60 net/bluetooth/sco.c:593 __sys_connect_file+0x153/0x1a0 net/socket.c:2001 __sys_connect+0x165/0x1a0 net/socket.c:2018 __do_sys_connect net/socket.c:2028 [inline] __se_sys_connect net/socket.c:2025 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:2025 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 lock_sock_nested+0x3a/0xf0 net/core/sock.c:3474 lock_sock include/net/sock.h:1697 [inline] sco_sock_timeout+0xd1/0x290 net/bluetooth/sco.c:97 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 other info that might help us debug this: Chain exists of: sk_lock-AF_BLUETOOTH-BTPROTO_SCO --> hci_cb_list_lock --> (work_completion)(&(&conn->timeout_work)->work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&(&conn->timeout_work)->work)); lock(hci_cb_list_lock); lock((work_completion)(&(&conn->timeout_work)->work)); lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO); *** DEADLOCK *** 2 locks held by kworker/0:2/898: #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:639 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:666 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x87a/0x15c0 kernel/workqueue.c:2361 #1: ffffc900042e7da8 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365 stack backtrace: CPU: 0 PID: 898 Comm: kworker/0:2 Not tainted 6.3.0-rc6-syzkaller-ge62252bc55b6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Workqueue: events sco_sock_timeout Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 lock_sock_nested+0x3a/0xf0 net/core/sock.c:3474 lock_sock include/net/sock.h:1697 [inline] sco_sock_timeout+0xd1/0x290 net/bluetooth/sco.c:97 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308