====================================================== WARNING: possible circular locking dependency detected 6.1.38-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/920 is trying to acquire lock: ffff88801b316470 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: __flush_work+0xcf/0x1a0 kernel/workqueue.c:3069 but task is already holding lock: ffffffff8e1eee68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1791 [inline] ffffffff8e1eee68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x280 net/bluetooth/hci_conn.c:2457 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:5669 __mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 hci_connect_cfm include/net/bluetooth/hci_core.h:1776 [inline] hci_remote_features_evt+0x671/0xaa0 net/bluetooth/hci_event.c:3753 hci_event_func net/bluetooth/hci_event.c:7476 [inline] hci_event_packet+0x96c/0x1360 net/bluetooth/hci_event.c:7528 hci_rx_work+0x40d/0xa80 net/bluetooth/hci_core.c:4060 process_one_work+0x8aa/0x11f0 kernel/workqueue.c:2289 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436 kthread+0x26e/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 -> #2 (&hdev->lock){+.+.}-{3:3}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 __mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 sco_sock_connect+0x181/0x8d0 net/bluetooth/sco.c:593 __sys_connect_file net/socket.c:1976 [inline] __sys_connect+0x2c9/0x300 net/socket.c:1993 __do_sys_connect net/socket.c:2003 [inline] __se_sys_connect net/socket.c:2000 [inline] __x64_sys_connect+0x76/0x80 net/socket.c:2000 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+0x63/0xcd -> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 lock_sock_nested+0x44/0x100 net/core/sock.c:3452 lock_sock include/net/sock.h:1733 [inline] sco_sock_timeout+0xbd/0x230 net/bluetooth/sco.c:97 process_one_work+0x8aa/0x11f0 kernel/workqueue.c:2289 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436 kthread+0x26e/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 -> #0 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 __flush_work+0xeb/0x1a0 kernel/workqueue.c:3069 __cancel_work_timer+0x519/0x6a0 kernel/workqueue.c:3160 sco_conn_del+0x205/0x300 net/bluetooth/sco.c:205 hci_disconn_cfm include/net/bluetooth/hci_core.h:1794 [inline] hci_conn_hash_flush+0x10e/0x280 net/bluetooth/hci_conn.c:2457 hci_dev_close_sync+0xa2d/0x1000 net/bluetooth/hci_sync.c:4891 hci_dev_do_close net/bluetooth/hci_core.c:554 [inline] hci_unregister_dev+0x1df/0x480 net/bluetooth/hci_core.c:2704 vhci_release+0x7f/0xd0 drivers/bluetooth/hci_vhci.c:568 __fput+0x3b7/0x890 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x6fb/0x2300 kernel/exit.c:869 do_group_exit+0x202/0x2b0 kernel/exit.c:1019 get_signal+0x16f7/0x17d0 kernel/signal.c:2858 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd 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 *** 3 locks held by syz-executor.3/920: #0: ffff888073c910b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] #0: ffff888073c910b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1d7/0x480 net/bluetooth/hci_core.c:2704 #1: ffff888073c90078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x445/0x1000 net/bluetooth/hci_sync.c:4878 #2: ffffffff8e1eee68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1791 [inline] #2: ffffffff8e1eee68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x280 net/bluetooth/hci_conn.c:2457 stack backtrace: CPU: 0 PID: 920 Comm: syz-executor.3 Not tainted 6.1.38-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 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:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 __flush_work+0xeb/0x1a0 kernel/workqueue.c:3069 __cancel_work_timer+0x519/0x6a0 kernel/workqueue.c:3160 sco_conn_del+0x205/0x300 net/bluetooth/sco.c:205 hci_disconn_cfm include/net/bluetooth/hci_core.h:1794 [inline] hci_conn_hash_flush+0x10e/0x280 net/bluetooth/hci_conn.c:2457 hci_dev_close_sync+0xa2d/0x1000 net/bluetooth/hci_sync.c:4891 hci_dev_do_close net/bluetooth/hci_core.c:554 [inline] hci_unregister_dev+0x1df/0x480 net/bluetooth/hci_core.c:2704 vhci_release+0x7f/0xd0 drivers/bluetooth/hci_vhci.c:568 __fput+0x3b7/0x890 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x6fb/0x2300 kernel/exit.c:869 do_group_exit+0x202/0x2b0 kernel/exit.c:1019 get_signal+0x16f7/0x17d0 kernel/signal.c:2858 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7feaf64a7f35 Code: Unable to access opcode bytes at 0x7feaf64a7f0b. RSP: 002b:00007feaf7258010 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007feaf659bf80 RCX: 00007feaf64a7f35 RDX: 00007feaf7258050 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007feaf64c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000000b R14: 00007feaf659bf80 R15: 00007ffe56cf7e98