program: r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x2, 0x0) connect$bt_l2cap(r0, &(0x7f0000000080)={0x1f, 0x0, @fixed={'\xaa\xaa\xaa\xaa\xaa', 0x10}, 0x7ff}, 0xe) r1 = syz_init_net_socket$bt_hidp(0x1f, 0x3, 0x6) ioctl$sock_bt_hidp_HIDPCONNADD(r1, 0x400448c8, &(0x7f0000000280)={r0, r0, 0xc, 0x1, &(0x7f0000000340)='\x00', 0x9, 0x1, 0x457, 0x9, 0x9, 0x1, 0x1, 'syz1\x00'}) r2 = syz_init_net_socket$bt_hci(0x1f, 0x3, 0x1) ioctl$sock_bt_hci(r2, 0x400448ca, 0x0) [ 85.036746][ T9] hid-multitouch 0005:0457:0009.0002: unknown main item tag 0x0 [ 85.069788][ T9] hid-multitouch 0005:0457:0009.0002: hidraw1: BLUETOOTH HID v0.09 Device [syz1] on aa:aa:aa:aa:aa:aa [ 85.110515][ T5329] [ 85.111710][ T5329] ====================================================== [ 85.114925][ T5329] WARNING: possible circular locking dependency detected [ 85.117959][ T5329] syzkaller #0 Not tainted [ 85.119940][ T5329] ------------------------------------------------------ [ 85.122732][ T5329] syz.0.0/5329 is trying to acquire lock: [ 85.124999][ T5329] ffff888011c5f040 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 [ 85.129640][ T5329] [ 85.129640][ T5329] but task is already holding lock: [ 85.132542][ T5329] ffff888011c5f338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 [ 85.136204][ T5329] [ 85.136204][ T5329] which lock already depends on the new lock. [ 85.136204][ T5329] [ 85.140505][ T5329] [ 85.140505][ T5329] the existing dependency chain (in reverse order) is: [ 85.144223][ T5329] [ 85.144223][ T5329] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 85.147233][ T5329] __mutex_lock+0x19f/0x1300 [ 85.149400][ T5329] l2cap_info_timeout+0x60/0xa0 [ 85.151530][ T5329] process_scheduled_works+0xaec/0x17a0 [ 85.154125][ T5329] worker_thread+0xda6/0x1360 [ 85.156404][ T5329] kthread+0x726/0x8b0 [ 85.158421][ T5329] ret_from_fork+0x51b/0xa40 [ 85.160556][ T5329] ret_from_fork_asm+0x1a/0x30 [ 85.163208][ T5329] [ 85.163208][ T5329] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 85.167871][ T5329] __lock_acquire+0x15a5/0x2cf0 [ 85.170301][ T5329] lock_acquire+0x106/0x330 [ 85.172414][ T5329] __flush_work+0x700/0xc50 [ 85.174581][ T5329] __cancel_work_sync+0xbe/0x110 [ 85.177048][ T5329] l2cap_conn_del+0x402/0x5b0 [ 85.179440][ T5329] hci_conn_hash_flush+0x10d/0x260 [ 85.181858][ T5329] hci_dev_close_sync+0x821/0x10e0 [ 85.184278][ T5329] hci_dev_close+0x108/0x260 [ 85.186488][ T5329] sock_do_ioctl+0x101/0x320 [ 85.188848][ T5329] sock_ioctl+0x5c6/0x7f0 [ 85.191061][ T5329] __se_sys_ioctl+0xfc/0x170 [ 85.193444][ T5329] do_syscall_64+0xe2/0xf80 [ 85.195764][ T5329] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.198531][ T5329] [ 85.198531][ T5329] other info that might help us debug this: [ 85.198531][ T5329] [ 85.202906][ T5329] Possible unsafe locking scenario: [ 85.202906][ T5329] [ 85.206088][ T5329] CPU0 CPU1 [ 85.208510][ T5329] ---- ---- [ 85.210947][ T5329] lock(&conn->lock#2); [ 85.212969][ T5329] lock((work_completion)(&(&conn->info_timer)->work)); [ 85.217128][ T5329] lock(&conn->lock#2); [ 85.220351][ T5329] lock((work_completion)(&(&conn->info_timer)->work)); [ 85.223469][ T5329] [ 85.223469][ T5329] *** DEADLOCK *** [ 85.223469][ T5329] [ 85.227035][ T5329] 5 locks held by syz.0.0/5329: [ 85.229243][ T5329] #0: ffff88801a78cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x260 [ 85.233505][ T5329] #1: ffff88801a78c0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 [ 85.237464][ T5329] #2: ffffffff8fb3b268 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 [ 85.241718][ T5329] #3: ffff888011c5f338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 [ 85.245845][ T5329] #4: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 [ 85.249938][ T5329] [ 85.249938][ T5329] stack backtrace: [ 85.252512][ T5329] CPU: 0 UID: 0 PID: 5329 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 85.252529][ T5329] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 85.252537][ T5329] Call Trace: [ 85.252545][ T5329] [ 85.252551][ T5329] dump_stack_lvl+0xe8/0x150 [ 85.252571][ T5329] print_circular_bug+0x2e1/0x300 [ 85.252586][ T5329] check_noncircular+0x12e/0x150 [ 85.252599][ T5329] __lock_acquire+0x15a5/0x2cf0 [ 85.252618][ T5329] ? do_raw_spin_lock+0x12b/0x2f0 [ 85.252634][ T5329] ? __flush_work+0x100/0xc50 [ 85.252645][ T5329] lock_acquire+0x106/0x330 [ 85.252658][ T5329] ? __flush_work+0x100/0xc50 [ 85.252671][ T5329] ? __flush_work+0x100/0xc50 [ 85.252682][ T5329] __flush_work+0x700/0xc50 [ 85.252693][ T5329] ? __flush_work+0x100/0xc50 [ 85.252704][ T5329] ? __flush_work+0x100/0xc50 [ 85.252713][ T5329] ? __pfx___flush_work+0x10/0x10 [ 85.252724][ T5329] ? __pfx_wq_barrier_func+0x10/0x10 [ 85.252745][ T5329] ? __cancel_work_sync+0x5c/0x110 [ 85.252758][ T5329] __cancel_work_sync+0xbe/0x110 [ 85.252770][ T5329] l2cap_conn_del+0x402/0x5b0 [ 85.252783][ T5329] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 85.252791][ T5329] hci_conn_hash_flush+0x10d/0x260 [ 85.252800][ T5329] hci_dev_close_sync+0x821/0x10e0 [ 85.252808][ T5329] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 85.252815][ T5329] ? lockdep_hardirqs_on+0x7a/0x110 [ 85.252822][ T5329] ? enable_work+0x1fd/0x230 [ 85.252830][ T5329] hci_dev_close+0x108/0x260 [ 85.252837][ T5329] sock_do_ioctl+0x101/0x320 [ 85.252849][ T5329] ? __pfx_sock_do_ioctl+0x10/0x10 [ 85.252857][ T5329] ? do_futex+0x395/0x420 [ 85.252869][ T5329] sock_ioctl+0x5c6/0x7f0 [ 85.252878][ T5329] ? __pfx_sock_ioctl+0x10/0x10 [ 85.252887][ T5329] ? __fget_files+0x2a/0x420 [ 85.252895][ T5329] ? __fget_files+0x3a0/0x420 [ 85.252901][ T5329] ? __fget_files+0x2a/0x420 [ 85.252908][ T5329] ? bpf_lsm_file_ioctl+0x9/0x20 [ 85.252916][ T5329] ? __pfx_sock_ioctl+0x10/0x10 [ 85.252925][ T5329] __se_sys_ioctl+0xfc/0x170 [ 85.252934][ T5329] do_syscall_64+0xe2/0xf80 [ 85.252942][ T5329] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.252952][ T5329] ? trace_irq_disable+0x37/0x100 [ 85.252962][ T5329] ? clear_bhb_loop+0x60/0xb0 [ 85.252974][ T5329] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.252984][ T5329] RIP: 0033:0x7fb556f9aeb9 [ 85.252995][ T5329] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 [ 85.253004][ T5329] RSP: 002b:00007fb557d84028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 85.253017][ T5329] RAX: ffffffffffffffda RBX: 00007fb557215fa0 RCX: 00007fb556f9aeb9 [ 85.253025][ T5329] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000006 [ 85.253031][ T5329] RBP: 00007fb557008c1f R08: 0000000000000000 R09: 0000000000000000 [ 85.253038][ T5329] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 85.253044][ T5329] R13: 00007fb557216038 R14: 00007fb557215fa0 R15: 00007ffcaa5338b8 [ 85.253055][ T5329] [ 85.396946][ T5304] Bluetooth: hci0: command tx timeout [ 85.425673][ T5334] fido_id[5334]: Failed to open report descriptor at '/sys/devices/virtual/bluetooth/hci0/hci0:200/report_descriptor': No such file or directory [ 87.414785][ T5304] Bluetooth: hci0: command tx timeout [ 89.495001][ T5304] Bluetooth: hci0: command tx timeout