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$bt_hidp(0x1f, 0x3, 0x6) syz_open_procfs(0x0, 0x0) ioctl$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) [ 119.137584][ T5313] Bluetooth: hci0: command tx timeout [ 119.318585][ T53] hid-multitouch 0005:0457:0009.0002: unknown main item tag 0x0 [ 119.355050][ T53] hid-multitouch 0005:0457:0009.0002: hidraw1: BLUETOOTH HID v0.09 Device [syz1] on aa:aa:aa:aa:aa:aa [ 119.401471][ T5333] [ 119.402885][ T5333] ====================================================== [ 119.406631][ T5333] WARNING: possible circular locking dependency detected [ 119.410244][ T5333] syzkaller #0 Not tainted [ 119.412263][ T5333] ------------------------------------------------------ [ 119.415399][ T5333] syz.0.0/5333 is trying to acquire lock: [ 119.418280][ T5333] ffff888037cba040 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 [ 119.424507][ T5333] [ 119.424507][ T5333] but task is already holding lock: [ 119.427579][ T5333] ffff888037cba2f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 [ 119.431617][ T5333] [ 119.431617][ T5333] which lock already depends on the new lock. [ 119.431617][ T5333] [ 119.438198][ T5333] [ 119.438198][ T5333] the existing dependency chain (in reverse order) is: [ 119.442590][ T5333] [ 119.442590][ T5333] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 119.446065][ T5333] __mutex_lock+0x19f/0x1300 [ 119.448427][ T5333] l2cap_info_timeout+0x60/0xa0 [ 119.451358][ T5333] process_scheduled_works+0xb6e/0x18c0 [ 119.454846][ T5333] worker_thread+0xa53/0xfc0 [ 119.457209][ T5333] kthread+0x388/0x470 [ 119.459135][ T5333] ret_from_fork+0x51e/0xb90 [ 119.461354][ T5333] ret_from_fork_asm+0x1a/0x30 [ 119.463585][ T5333] [ 119.463585][ T5333] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 119.467889][ T5333] __lock_acquire+0x15a5/0x2cf0 [ 119.470653][ T5333] lock_acquire+0xf0/0x2e0 [ 119.473146][ T5333] __flush_work+0x700/0xc50 [ 119.475695][ T5333] __cancel_work_sync+0xbe/0x110 [ 119.478096][ T5333] l2cap_conn_del+0x40f/0x5c0 [ 119.480509][ T5333] hci_conn_hash_flush+0x10d/0x260 [ 119.482806][ T5333] hci_dev_close_sync+0x821/0x10e0 [ 119.485766][ T5333] hci_dev_close+0x108/0x260 [ 119.488741][ T5333] sock_do_ioctl+0x101/0x320 [ 119.491123][ T5333] sock_ioctl+0x5c6/0x7f0 [ 119.493301][ T5333] __se_sys_ioctl+0xfc/0x170 [ 119.495610][ T5333] do_syscall_64+0x14d/0xf80 [ 119.497857][ T5333] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 119.500758][ T5333] [ 119.500758][ T5333] other info that might help us debug this: [ 119.500758][ T5333] [ 119.506951][ T5333] Possible unsafe locking scenario: [ 119.506951][ T5333] [ 119.510345][ T5333] CPU0 CPU1 [ 119.512535][ T5333] ---- ---- [ 119.514830][ T5333] lock(&conn->lock#2); [ 119.516762][ T5333] lock((work_completion)(&(&conn->info_timer)->work)); [ 119.521631][ T5333] lock(&conn->lock#2); [ 119.525086][ T5333] lock((work_completion)(&(&conn->info_timer)->work)); [ 119.528723][ T5333] [ 119.528723][ T5333] *** DEADLOCK *** [ 119.528723][ T5333] [ 119.532277][ T5333] 5 locks held by syz.0.0/5333: [ 119.534769][ T5333] #0: ffff888039098ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x260 [ 119.539585][ T5333] #1: ffff8880390980c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 [ 119.543870][ T5333] #2: ffffffff8fd5d0a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 [ 119.547906][ T5333] #3: ffff888037cba2f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 [ 119.552374][ T5333] #4: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 [ 119.556262][ T5333] [ 119.556262][ T5333] stack backtrace: [ 119.559111][ T5333] CPU: 0 UID: 0 PID: 5333 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 119.559131][ T5333] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 119.559146][ T5333] Call Trace: [ 119.559156][ T5333] [ 119.559164][ T5333] dump_stack_lvl+0xe8/0x150 [ 119.559189][ T5333] print_circular_bug+0x2e1/0x300 [ 119.559214][ T5333] check_noncircular+0x12e/0x150 [ 119.559236][ T5333] __lock_acquire+0x15a5/0x2cf0 [ 119.559257][ T5333] ? do_raw_spin_lock+0x12b/0x2f0 [ 119.559273][ T5333] ? do_raw_spin_unlock+0x4d/0x210 [ 119.559286][ T5333] lock_acquire+0xf0/0x2e0 [ 119.559300][ T5333] ? __flush_work+0x100/0xc50 [ 119.559319][ T5333] ? __flush_work+0x100/0xc50 [ 119.559335][ T5333] __flush_work+0x700/0xc50 [ 119.559351][ T5333] ? __flush_work+0x100/0xc50 [ 119.559365][ T5333] ? __flush_work+0x100/0xc50 [ 119.559382][ T5333] ? __pfx___flush_work+0x10/0x10 [ 119.559399][ T5333] ? __pfx_wq_barrier_func+0x10/0x10 [ 119.559418][ T5333] ? __cancel_work_sync+0x5c/0x110 [ 119.559433][ T5333] __cancel_work_sync+0xbe/0x110 [ 119.559449][ T5333] l2cap_conn_del+0x40f/0x5c0 [ 119.559468][ T5333] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 119.559489][ T5333] hci_conn_hash_flush+0x10d/0x260 [ 119.559513][ T5333] hci_dev_close_sync+0x821/0x10e0 [ 119.559533][ T5333] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 119.559549][ T5333] ? lockdep_hardirqs_on+0x7a/0x110 [ 119.559563][ T5333] ? enable_work+0x1fd/0x230 [ 119.559590][ T5333] hci_dev_close+0x108/0x260 [ 119.559612][ T5333] sock_do_ioctl+0x101/0x320 [ 119.559629][ T5333] ? __pfx_sock_do_ioctl+0x10/0x10 [ 119.559641][ T5333] ? do_futex+0x395/0x420 [ 119.559660][ T5333] sock_ioctl+0x5c6/0x7f0 [ 119.559672][ T5333] ? __pfx_sock_ioctl+0x10/0x10 [ 119.559683][ T5333] ? __fget_files+0x2a/0x420 [ 119.559699][ T5333] ? __fget_files+0x3a0/0x420 [ 119.559713][ T5333] ? __fget_files+0x2a/0x420 [ 119.559727][ T5333] ? bpf_lsm_file_ioctl+0x9/0x20 [ 119.559749][ T5333] ? __pfx_sock_ioctl+0x10/0x10 [ 119.559763][ T5333] __se_sys_ioctl+0xfc/0x170 [ 119.559783][ T5333] do_syscall_64+0x14d/0xf80 [ 119.559798][ T5333] ? trace_irq_disable+0x3b/0x150 [ 119.559818][ T5333] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 119.559832][ T5333] ? clear_bhb_loop+0x40/0x90 [ 119.559847][ T5333] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 119.559861][ T5333] RIP: 0033:0x7f0ea479c799 [ 119.559873][ T5333] 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 [ 119.559883][ T5333] RSP: 002b:00007f0ea5639fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 119.559906][ T5333] RAX: ffffffffffffffda RBX: 00007f0ea4a15fa0 RCX: 00007f0ea479c799 [ 119.559916][ T5333] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000006 [ 119.559925][ T5333] RBP: 00007f0ea4832c99 R08: 0000000000000000 R09: 0000000000000000 [ 119.559934][ T5333] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 119.559942][ T5333] R13: 00007f0ea4a16038 R14: 00007f0ea4a15fa0 R15: 00007ffdf43cb0a8 [ 119.559958][ T5333] [ 119.713929][ T5342] fido_id[5342]: Failed to open report descriptor at '/sys/devices/virtual/bluetooth/hci0/hci0:200/report_descriptor': No such file or directory [ 121.165683][ T5313] Bluetooth: hci0: command tx timeout [ 123.246699][ T5313] Bluetooth: hci0: command tx timeout [ 125.326131][ T5313] Bluetooth: hci0: command tx timeout