======================================================
WARNING: possible circular locking dependency detected
6.10.0-syzkaller-08676-g720261cfc732 #0 Not tainted
------------------------------------------------------
kworker/u33:1/4645 is trying to acquire lock:
ffff88802bef0258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
ffff88802bef0258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_conn_ready net/bluetooth/sco.c:1290 [inline]
ffff88802bef0258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_connect_cfm+0x466/0xbd0 net/bluetooth/sco.c:1362

but task is already holding lock:
ffff888046622820 (&conn->lock#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff888046622820 (&conn->lock#2){+.+.}-{2:2}, at: sco_conn_ready net/bluetooth/sco.c:1277 [inline]
ffff888046622820 (&conn->lock#2){+.+.}-{2:2}, at: sco_connect_cfm+0x2d1/0xbd0 net/bluetooth/sco.c:1362

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&conn->lock#2){+.+.}-{2:2}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       sco_chan_add net/bluetooth/sco.c:234 [inline]
       sco_connect net/bluetooth/sco.c:287 [inline]
       sco_sock_connect+0x3a1/0xb10 net/bluetooth/sco.c:596
       __sys_connect_file+0x15f/0x1a0 net/socket.c:2061
       __sys_connect+0x149/0x170 net/socket.c:2078
       __do_sys_connect net/socket.c:2088 [inline]
       __se_sys_connect net/socket.c:2085 [inline]
       __ia32_sys_connect+0x71/0xb0 net/socket.c:2085
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3133 [inline]
       check_prevs_add kernel/locking/lockdep.c:3252 [inline]
       validate_chain kernel/locking/lockdep.c:3868 [inline]
       __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142
       lock_acquire kernel/locking/lockdep.c:5759 [inline]
       lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
       lock_sock_nested+0x3a/0xf0 net/core/sock.c:3543
       lock_sock include/net/sock.h:1607 [inline]
       sco_conn_ready net/bluetooth/sco.c:1290 [inline]
       sco_connect_cfm+0x466/0xbd0 net/bluetooth/sco.c:1362
       hci_connect_cfm include/net/bluetooth/hci_core.h:1965 [inline]
       hci_sync_conn_complete_evt+0x3a1/0xa10 net/bluetooth/hci_event.c:5008
       hci_event_func net/bluetooth/hci_event.c:7445 [inline]
       hci_event_packet+0x9eb/0x1190 net/bluetooth/hci_event.c:7497
       hci_rx_work+0x2c6/0x1610 net/bluetooth/hci_core.c:4029
       process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231
       process_scheduled_works kernel/workqueue.c:3312 [inline]
       worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
       kthread+0x2c1/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&conn->lock#2);
                               lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO);
                               lock(&conn->lock#2);
  lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO);

 *** DEADLOCK ***

5 locks held by kworker/u33:1/4645:
 #0: ffff888050133948 ((wq_completion)hci1#2){+.+.}-{0:0}, at: process_one_work+0x11f0/0x1ad0 kernel/workqueue.c:3206
 #1: ffffc900272b7d80 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1ad0 kernel/workqueue.c:3207
 #2: ffff88806767c078 (&hdev->lock){+.+.}-{3:3}, at: hci_sync_conn_complete_evt+0x118/0xa10 net/bluetooth/hci_event.c:4925
 #3: ffffffff8f9b1688 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1962 [inline]
 #3: ffffffff8f9b1688 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_sync_conn_complete_evt+0x336/0xa10 net/bluetooth/hci_event.c:5008
 #4: ffff888046622820 (&conn->lock#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #4: ffff888046622820 (&conn->lock#2){+.+.}-{2:2}, at: sco_conn_ready net/bluetooth/sco.c:1277 [inline]
 #4: ffff888046622820 (&conn->lock#2){+.+.}-{2:2}, at: sco_connect_cfm+0x2d1/0xbd0 net/bluetooth/sco.c:1362

stack backtrace:
CPU: 3 PID: 4645 Comm: kworker/u33:1 Not tainted 6.10.0-syzkaller-08676-g720261cfc732 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: hci1 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2186
 check_prev_add kernel/locking/lockdep.c:3133 [inline]
 check_prevs_add kernel/locking/lockdep.c:3252 [inline]
 validate_chain kernel/locking/lockdep.c:3868 [inline]
 __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142
 lock_acquire kernel/locking/lockdep.c:5759 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
 lock_sock_nested+0x3a/0xf0 net/core/sock.c:3543
 lock_sock include/net/sock.h:1607 [inline]
 sco_conn_ready net/bluetooth/sco.c:1290 [inline]
 sco_connect_cfm+0x466/0xbd0 net/bluetooth/sco.c:1362
 hci_connect_cfm include/net/bluetooth/hci_core.h:1965 [inline]
 hci_sync_conn_complete_evt+0x3a1/0xa10 net/bluetooth/hci_event.c:5008
 hci_event_func net/bluetooth/hci_event.c:7445 [inline]
 hci_event_packet+0x9eb/0x1190 net/bluetooth/hci_event.c:7497
 hci_rx_work+0x2c6/0x1610 net/bluetooth/hci_core.c:4029
 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
BUG: sleeping function called from invalid context at net/core/sock.c:3545
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 4645, name: kworker/u33:1
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 3 PID: 4645 Comm: kworker/u33:1 Not tainted 6.10.0-syzkaller-08676-g720261cfc732 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: hci1 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:114
 __might_resched+0x3c0/0x5e0 kernel/sched/core.c:8437
 lock_sock_nested+0x4b/0xf0 net/core/sock.c:3545
 lock_sock include/net/sock.h:1607 [inline]
 sco_conn_ready net/bluetooth/sco.c:1290 [inline]
 sco_connect_cfm+0x466/0xbd0 net/bluetooth/sco.c:1362
 hci_connect_cfm include/net/bluetooth/hci_core.h:1965 [inline]
 hci_sync_conn_complete_evt+0x3a1/0xa10 net/bluetooth/hci_event.c:5008
 hci_event_func net/bluetooth/hci_event.c:7445 [inline]
 hci_event_packet+0x9eb/0x1190 net/bluetooth/hci_event.c:7497
 hci_rx_work+0x2c6/0x1610 net/bluetooth/hci_core.c:4029
 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>