====================================================== WARNING: possible circular locking dependency detected 5.15.124-syzkaller #0 Not tainted ------------------------------------------------------ kworker/1:4/32123 is trying to acquire lock: ffff888075328120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1661 [inline] ffff888075328120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_sock_timeout+0xbd/0x230 net/bluetooth/sco.c:96 but task is already holding lock: ffffc9000524fd20 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 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}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __flush_work+0xeb/0x1a0 kernel/workqueue.c:3090 __cancel_work_timer+0x519/0x6a0 kernel/workqueue.c:3181 sco_conn_del+0x205/0x300 net/bluetooth/sco.c:204 hci_disconn_cfm include/net/bluetooth/hci_core.h:1521 [inline] hci_conn_hash_flush+0x10d/0x210 net/bluetooth/hci_conn.c:1610 hci_dev_do_close+0x9f6/0x1000 net/bluetooth/hci_core.c:1795 hci_unregister_dev+0x2a7/0x510 net/bluetooth/hci_core.c:4033 vhci_release+0x73/0xc0 drivers/bluetooth/hci_vhci.c:342 __fput+0x3bf/0x890 fs/file_table.c:280 task_work_run+0x129/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x6a3/0x2480 kernel/exit.c:872 do_group_exit+0x144/0x310 kernel/exit.c:994 get_signal+0xc66/0x14e0 kernel/signal.c:2889 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb -> #2 (hci_cb_list_lock){+.+.}-{3:3}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hci_connect_cfm include/net/bluetooth/hci_core.h:1503 [inline] hci_remote_features_evt+0x6d1/0xb50 net/bluetooth/hci_event.c:3323 hci_event_packet+0x6da/0x1480 net/bluetooth/hci_event.c:6376 hci_rx_work+0x240/0x7d0 net/bluetooth/hci_core.c:5153 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 -> #1 (&hdev->lock){+.+.}-{3:3}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 sco_sock_connect+0x181/0x8c0 net/bluetooth/sco.c:587 __sys_connect_file net/socket.c:1899 [inline] __sys_connect+0x38b/0x410 net/socket.c:1916 __do_sys_connect net/socket.c:1926 [inline] __se_sys_connect net/socket.c:1923 [inline] __x64_sys_connect+0x76/0x80 net/socket.c:1923 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 lock_sock_nested+0x44/0x100 net/core/sock.c:3227 lock_sock include/net/sock.h:1661 [inline] sco_sock_timeout+0xbd/0x230 net/bluetooth/sco.c:96 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 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/1:4/32123: #0: ffff888011c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000524fd20 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 stack backtrace: CPU: 1 PID: 32123 Comm: kworker/1:4 Not tainted 5.15.124-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 Workqueue: events sco_sock_timeout Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 lock_sock_nested+0x44/0x100 net/core/sock.c:3227 lock_sock include/net/sock.h:1661 [inline] sco_sock_timeout+0xbd/0x230 net/bluetooth/sco.c:96 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298