====================================================== base_sock_release(ffff888069c6f180) sk=ffff88806f949480 WARNING: possible circular locking dependency detected 4.14.232-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/3390 is trying to acquire lock: ("%s"hdev->name#2){+.+.}, at: [] start_flush_work kernel/workqueue.c:2860 [inline] ("%s"hdev->name#2){+.+.}, at: [] flush_work+0x387/0x770 kernel/workqueue.c:2892 but task is already holding lock: (&hdev->lock){+.+.}, at: [] hci_dev_do_reset net/bluetooth/hci_core.c:1722 [inline] (&hdev->lock){+.+.}, at: [] hci_dev_reset+0x12c/0x3a0 net/bluetooth/hci_core.c:1763 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&hdev->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 hci_cc_write_scan_enable net/bluetooth/hci_event.c:375 [inline] hci_cmd_complete_evt+0x4d34/0xb490 net/bluetooth/hci_event.c:2831 hci_event_packet+0x21ce/0x7510 net/bluetooth/hci_event.c:5330 hci_rx_work+0x427/0xb40 net/bluetooth/hci_core.c:4246 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #1 ((&hdev->rx_work)){+.+.}: process_one_work+0x736/0x14a0 kernel/workqueue.c:2092 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #0 ("%s"hdev->name#2){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 start_flush_work kernel/workqueue.c:2861 [inline] flush_work+0x3ac/0x770 kernel/workqueue.c:2892 __cancel_work_timer+0x321/0x460 kernel/workqueue.c:2964 hci_conn_del+0x52/0x6f0 net/bluetooth/hci_conn.c:575 hci_conn_hash_flush+0x19c/0x260 net/bluetooth/hci_conn.c:1394 hci_dev_do_reset net/bluetooth/hci_core.c:1724 [inline] hci_dev_reset+0x13c/0x3a0 net/bluetooth/hci_core.c:1763 hci_sock_ioctl+0x429/0x690 net/bluetooth/hci_sock.c:1023 sock_do_ioctl net/socket.c:974 [inline] sock_ioctl+0x2cc/0x4c0 net/socket.c:1071 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: "%s"hdev->name#2 --> (&hdev->rx_work) --> &hdev->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&hdev->lock); lock((&hdev->rx_work)); lock(&hdev->lock); lock("%s"hdev->name#2); *** DEADLOCK *** 2 locks held by syz-executor.0/3390: #0: (&hdev->req_lock){+.+.}, at: [] hci_dev_do_reset net/bluetooth/hci_core.c:1711 [inline] #0: (&hdev->req_lock){+.+.}, at: [] hci_dev_reset+0xd8/0x3a0 net/bluetooth/hci_core.c:1763 #1: (&hdev->lock){+.+.}, at: [] hci_dev_do_reset net/bluetooth/hci_core.c:1722 [inline] #1: (&hdev->lock){+.+.}, at: [] hci_dev_reset+0x12c/0x3a0 net/bluetooth/hci_core.c:1763 stack backtrace: CPU: 0 PID: 3390 Comm: syz-executor.0 Not tainted 4.14.232-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 start_flush_work kernel/workqueue.c:2861 [inline] flush_work+0x3ac/0x770 kernel/workqueue.c:2892 __cancel_work_timer+0x321/0x460 kernel/workqueue.c:2964 hci_conn_del+0x52/0x6f0 net/bluetooth/hci_conn.c:575 hci_conn_hash_flush+0x19c/0x260 net/bluetooth/hci_conn.c:1394 hci_dev_do_reset net/bluetooth/hci_core.c:1724 [inline] hci_dev_reset+0x13c/0x3a0 net/bluetooth/hci_core.c:1763 hci_sock_ioctl+0x429/0x690 net/bluetooth/hci_sock.c:1023 sock_do_ioctl net/socket.c:974 [inline] sock_ioctl+0x2cc/0x4c0 net/socket.c:1071 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4665f9 RSP: 002b:00007ff33bbd5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000400448cb RDI: 0000000000000005 RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007ffed0ea65af R14: 00007ff33bbd5300 R15: 0000000000022000 base_sock_release(ffff888070658540) sk=ffff88809933f240 base_sock_release(ffff8880778c0140) sk=ffff8880b4438e40 base_sock_release(ffff888068cc7040) sk=ffff88809cadce00 base_sock_release(ffff88806ff8e4c0) sk=ffff8880a2aa8cc0 base_sock_release(ffff88807057e680) sk=ffff888093bae640 base_sock_release(ffff888069761a40) sk=ffff88807348c580 base_sock_release(ffff888069f5fac0) sk=ffff88807ccfe500 base_sock_release(ffff88806ff71080) sk=ffff88809b2e0440 base_sock_release(ffff88806b25a140) sk=ffff88809de70440 base_sock_release(ffff8880745f6ac0) sk=ffff8880ac00aac0 base_sock_release(ffff88807044f4c0) sk=ffff8880762feec0 base_sock_release(ffff88807278b4c0) sk=ffff8880af823680 base_sock_release(ffff88806eb224c0) sk=ffff8880a47254c0 base_sock_release(ffff88807686c0c0) sk=ffff8880815412c0 base_sock_release(ffff888068945a40) sk=ffff88808dbf9100