syzbot

Bluetooth: hci0: hardware error 0x00
======================================================
WARNING: possible circular locking dependency detected
5.15.153-syzkaller #0 Not tainted
------------------------------------------------------
kworker/u5:2/3505 is trying to acquire lock:
ffff888072ac5120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline]
ffff888072ac5120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_conn_del+0x104/0x300 net/bluetooth/sco.c:196

but task is already holding lock:
ffffffff8db25068 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1522 [inline]
ffffffff8db25068 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x220 net/bluetooth/hci_conn.c:1622

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:1507 [inline]
       hci_remote_features_evt+0x52f/0xb50 net/bluetooth/hci_event.c:3327
       hci_event_packet+0x6fe/0x1550 net/bluetooth/hci_event.c:6396
       hci_rx_work+0x232/0x990 net/bluetooth/hci_core.c:5156
       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: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:587
       __sys_connect_file net/socket.c:1918 [inline]
       __sys_connect+0x38b/0x410 net/socket.c:1935
       __do_sys_connect net/socket.c:1945 [inline]
       __se_sys_connect net/socket.c:1942 [inline]
       __x64_sys_connect+0x76/0x80 net/socket.c:1942
       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+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:1668 [inline]
       sco_conn_del+0x104/0x300 net/bluetooth/sco.c:196
       hci_disconn_cfm include/net/bluetooth/hci_core.h:1525 [inline]
       hci_conn_hash_flush+0x10d/0x220 net/bluetooth/hci_conn.c:1622
       hci_dev_do_close+0x9f6/0x1070 net/bluetooth/hci_core.c:1795
       hci_error_reset+0x106/0x2d0 net/bluetooth/hci_core.c:2341
       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 --> &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 ***

5 locks held by kworker/u5:2/3505:
 #0: ffff88801d1ab938 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90002567d20 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff888079230ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x63/0x1070 net/bluetooth/hci_core.c:1737
 #3: ffff888079230078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x431/0x1070 net/bluetooth/hci_core.c:1782
 #4: ffffffff8db25068 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1522 [inline]
 #4: ffffffff8db25068 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x220 net/bluetooth/hci_conn.c:1622

stack backtrace:
CPU: 1 PID: 3505 Comm: kworker/u5:2 Not tainted 5.15.153-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_error_reset
Call Trace:
 <TASK>
 __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+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:1668 [inline]
 sco_conn_del+0x104/0x300 net/bluetooth/sco.c:196
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1525 [inline]
 hci_conn_hash_flush+0x10d/0x220 net/bluetooth/hci_conn.c:1622
 hci_dev_do_close+0x9f6/0x1070 net/bluetooth/hci_core.c:1795
 hci_error_reset+0x106/0x2d0 net/bluetooth/hci_core.c:2341
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319