Bluetooth: unknown link type 28 ====================================================== WARNING: possible circular locking dependency detected 5.15.169-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u5:8/4184 is trying to acquire lock: ffff88801eff6120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1678 [inline] ffff88801eff6120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_conn_ready net/bluetooth/sco.c:1110 [inline] ffff88801eff6120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_connect_cfm+0x146/0xad0 net/bluetooth/sco.c:1201 but task is already holding lock: ffffffff8db7b4e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1502 [inline] ffffffff8db7b4e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_sync_conn_complete_evt+0x45f/0x9b0 net/bluetooth/hci_event.c:4551 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (hci_cb_list_lock){+.+.}-{3:3}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __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:1502 [inline] hci_remote_features_evt+0x52f/0xb50 net/bluetooth/hci_event.c:3352 hci_event_packet+0x6fe/0x1550 net/bluetooth/hci_event.c:6421 hci_rx_work+0x232/0x990 net/bluetooth/hci_core.c:5155 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #1 (&hdev->lock){+.+.}-{3:3}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __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+0x181/0x8e0 net/bluetooth/sco.c:591 __sys_connect_file net/socket.c:1923 [inline] __sys_connect+0x38b/0x410 net/socket.c:1940 __do_sys_connect net/socket.c:1950 [inline] __se_sys_connect net/socket.c:1947 [inline] __x64_sys_connect+0x76/0x80 net/socket.c:1947 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #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+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 lock_sock_nested+0x44/0x100 net/core/sock.c:3250 lock_sock include/net/sock.h:1678 [inline] sco_conn_ready net/bluetooth/sco.c:1110 [inline] sco_connect_cfm+0x146/0xad0 net/bluetooth/sco.c:1201 hci_connect_cfm include/net/bluetooth/hci_core.h:1505 [inline] hci_sync_conn_complete_evt+0x4ce/0x9b0 net/bluetooth/hci_event.c:4551 hci_event_packet+0xa12/0x1550 net/bluetooth/hci_event.c:6483 hci_rx_work+0x232/0x990 net/bluetooth/hci_core.c:5155 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 other info that might help us debug this: Chain exists of: sk_lock-AF_BLUETOOTH-BTPROTO_SCO --> &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(sk_lock-AF_BLUETOOTH-BTPROTO_SCO); *** DEADLOCK *** 4 locks held by kworker/u5:8/4184: #0: ffff8880790d3138 ((wq_completion)hci3#2){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90002fb7d20 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff88807c5c4078 (&hdev->lock){+.+.}-{3:3}, at: hci_sync_conn_complete_evt+0xab/0x9b0 net/bluetooth/hci_event.c:4471 #3: ffffffff8db7b4e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1502 [inline] #3: ffffffff8db7b4e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_sync_conn_complete_evt+0x45f/0x9b0 net/bluetooth/hci_event.c:4551 stack backtrace: CPU: 1 PID: 4184 Comm: kworker/u5:8 Not tainted 5.15.169-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: hci3 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 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+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 lock_sock_nested+0x44/0x100 net/core/sock.c:3250 lock_sock include/net/sock.h:1678 [inline] sco_conn_ready net/bluetooth/sco.c:1110 [inline] sco_connect_cfm+0x146/0xad0 net/bluetooth/sco.c:1201 hci_connect_cfm include/net/bluetooth/hci_core.h:1505 [inline] hci_sync_conn_complete_evt+0x4ce/0x9b0 net/bluetooth/hci_event.c:4551 hci_event_packet+0xa12/0x1550 net/bluetooth/hci_event.c:6483 hci_rx_work+0x232/0x990 net/bluetooth/hci_core.c:5155 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287