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$bt_hci(0x1f, 0x3, 0x1) ioctl$HCIINQUIRY(r2, 0x400448ca, 0x0) [ 84.500745][ T5304] hid-multitouch 0005:0457:0009.0002: unknown main item tag 0x0 [ 84.577386][ T5304] hid-multitouch 0005:0457:0009.0002: hidraw1: BLUETOOTH HID v0.09 Device [syz1] on aa:aa:aa:aa:aa:aa [ 84.643885][ T5317] [ 84.645086][ T5317] ====================================================== [ 84.648145][ T5317] WARNING: possible circular locking dependency detected [ 84.651233][ T5317] syzkaller #0 Not tainted [ 84.653277][ T5317] ------------------------------------------------------ [ 84.656386][ T5317] syz.0.0/5317 is trying to acquire lock: [ 84.658885][ T5317] ffff888041390840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 [ 84.664285][ T5317] [ 84.664285][ T5317] but task is already holding lock: [ 84.667483][ T5317] ffff888041390af8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 [ 84.671657][ T5317] [ 84.671657][ T5317] which lock already depends on the new lock. [ 84.671657][ T5317] [ 84.676237][ T5317] [ 84.676237][ T5317] the existing dependency chain (in reverse order) is: [ 84.680141][ T5317] [ 84.680141][ T5317] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 84.683414][ T5317] __mutex_lock+0x19f/0x1300 [ 84.685765][ T5317] l2cap_info_timeout+0x60/0xa0 [ 84.688188][ T5317] process_scheduled_works+0xb02/0x1830 [ 84.690902][ T5317] worker_thread+0xa50/0xfc0 [ 84.693074][ T5317] kthread+0x388/0x470 [ 84.694904][ T5317] ret_from_fork+0x51e/0xb90 [ 84.696959][ T5317] ret_from_fork_asm+0x1a/0x30 [ 84.699141][ T5317] [ 84.699141][ T5317] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 84.703333][ T5317] __lock_acquire+0x15a5/0x2cf0 [ 84.705664][ T5317] lock_acquire+0xf0/0x2e0 [ 84.707998][ T5317] __flush_work+0x700/0xc50 [ 84.710284][ T5317] __cancel_work_sync+0xbe/0x110 [ 84.712770][ T5317] l2cap_conn_del+0x40f/0x5c0 [ 84.715162][ T5317] hci_conn_hash_flush+0x10d/0x260 [ 84.717601][ T5317] hci_dev_close_sync+0x821/0x10e0 [ 84.720096][ T5317] hci_dev_close+0x108/0x260 [ 84.722408][ T5317] sock_do_ioctl+0x101/0x320 [ 84.725575][ T5317] sock_ioctl+0x5c6/0x7f0 [ 84.727744][ T5317] __se_sys_ioctl+0xfc/0x170 [ 84.730100][ T5317] do_syscall_64+0x14d/0xf80 [ 84.732419][ T5317] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 84.735248][ T5317] [ 84.735248][ T5317] other info that might help us debug this: [ 84.735248][ T5317] [ 84.739730][ T5317] Possible unsafe locking scenario: [ 84.739730][ T5317] [ 84.743033][ T5317] CPU0 CPU1 [ 84.745366][ T5317] ---- ---- [ 84.747745][ T5317] lock(&conn->lock#2); [ 84.749631][ T5317] lock((work_completion)(&(&conn->info_timer)->work)); [ 84.753707][ T5317] lock(&conn->lock#2); [ 84.756747][ T5317] lock((work_completion)(&(&conn->info_timer)->work)); [ 84.759849][ T5317] [ 84.759849][ T5317] *** DEADLOCK *** [ 84.759849][ T5317] [ 84.763447][ T5317] 5 locks held by syz.0.0/5317: [ 84.766084][ T5317] #0: ffff888012b4cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x260 [ 84.771041][ T5317] #1: ffff888012b4c0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 [ 84.775348][ T5317] #2: ffffffff8fd5b1e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 [ 84.779981][ T5317] #3: ffff888041390af8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 [ 84.783973][ T5317] #4: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 [ 84.787970][ T5317] [ 84.787970][ T5317] stack backtrace: [ 84.790743][ T5317] CPU: 0 UID: 0 PID: 5317 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 84.790759][ T5317] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 84.790766][ T5317] Call Trace: [ 84.790775][ T5317] [ 84.790781][ T5317] dump_stack_lvl+0xe8/0x150 [ 84.790803][ T5317] print_circular_bug+0x2e1/0x300 [ 84.790823][ T5317] check_noncircular+0x12e/0x150 [ 84.790841][ T5317] __lock_acquire+0x15a5/0x2cf0 [ 84.790855][ T5317] ? do_raw_spin_lock+0x12b/0x2f0 [ 84.790867][ T5317] ? do_raw_spin_unlock+0x4d/0x210 [ 84.790878][ T5317] lock_acquire+0xf0/0x2e0 [ 84.790890][ T5317] ? __flush_work+0x100/0xc50 [ 84.790928][ T5317] ? __flush_work+0x100/0xc50 [ 84.790945][ T5317] __flush_work+0x700/0xc50 [ 84.790960][ T5317] ? __flush_work+0x100/0xc50 [ 84.790974][ T5317] ? __flush_work+0x100/0xc50 [ 84.790988][ T5317] ? __pfx___flush_work+0x10/0x10 [ 84.791003][ T5317] ? __pfx_wq_barrier_func+0x10/0x10 [ 84.791019][ T5317] ? __cancel_work_sync+0x5c/0x110 [ 84.791040][ T5317] __cancel_work_sync+0xbe/0x110 [ 84.791054][ T5317] l2cap_conn_del+0x40f/0x5c0 [ 84.791071][ T5317] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 84.791085][ T5317] hci_conn_hash_flush+0x10d/0x260 [ 84.791100][ T5317] hci_dev_close_sync+0x821/0x10e0 [ 84.791113][ T5317] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 84.791123][ T5317] ? lockdep_hardirqs_on+0x7a/0x110 [ 84.791138][ T5317] ? enable_work+0x1fd/0x230 [ 84.791154][ T5317] hci_dev_close+0x108/0x260 [ 84.791166][ T5317] sock_do_ioctl+0x101/0x320 [ 84.791183][ T5317] ? __pfx_sock_do_ioctl+0x10/0x10 [ 84.791197][ T5317] ? do_futex+0x395/0x420 [ 84.791213][ T5317] sock_ioctl+0x5c6/0x7f0 [ 84.791227][ T5317] ? __pfx_sock_ioctl+0x10/0x10 [ 84.791240][ T5317] ? __fget_files+0x2a/0x420 [ 84.791280][ T5317] ? __fget_files+0x3a0/0x420 [ 84.791292][ T5317] ? __fget_files+0x2a/0x420 [ 84.791306][ T5317] ? bpf_lsm_file_ioctl+0x9/0x20 [ 84.791317][ T5317] ? __pfx_sock_ioctl+0x10/0x10 [ 84.791333][ T5317] __se_sys_ioctl+0xfc/0x170 [ 84.791349][ T5317] do_syscall_64+0x14d/0xf80 [ 84.791364][ T5317] ? trace_irq_disable+0x3b/0x150 [ 84.791378][ T5317] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 84.791388][ T5317] ? clear_bhb_loop+0x40/0x90 [ 84.791399][ T5317] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 84.791409][ T5317] RIP: 0033:0x7f343e59c629 [ 84.791421][ T5317] 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 [ 84.791430][ T5317] RSP: 002b:00007f343f457028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 84.791443][ T5317] RAX: ffffffffffffffda RBX: 00007f343e815fa0 RCX: 00007f343e59c629 [ 84.791451][ T5317] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000006 [ 84.791458][ T5317] RBP: 00007f343e632b39 R08: 0000000000000000 R09: 0000000000000000 [ 84.791465][ T5317] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 84.791471][ T5317] R13: 00007f343e816038 R14: 00007f343e815fa0 R15: 00007fff1c2b6c88 [ 84.791482][ T5317] [ 84.939307][ T5296] Bluetooth: hci0: command tx timeout [ 84.982893][ T5327] fido_id[5327]: Failed to open report descriptor at '/sys/devices/virtual/bluetooth/hci0/hci0:200/report_descriptor': No such file or directory [ 87.009913][ T5296] Bluetooth: hci0: command tx timeout [ 89.087710][ T5296] Bluetooth: hci0: command tx timeout