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) [ 84.891708][ T5317] hid-multitouch 0005:0457:0009.0002: unknown main item tag 0x0 [ 84.911366][ T5317] hid-multitouch 0005:0457:0009.0002: hidraw1: BLUETOOTH HID v0.09 Device [syz1] on aa:aa:aa:aa:aa:aa [ 84.947675][ T5322] [ 84.948857][ T5322] ====================================================== [ 84.951902][ T5322] WARNING: possible circular locking dependency detected [ 84.954974][ T5322] syzkaller #0 Not tainted [ 84.956871][ T5322] ------------------------------------------------------ [ 84.959965][ T5322] syz.0.0/5322 is trying to acquire lock: [ 84.962171][ T5322] ffff888040a08840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 [ 84.967270][ T5322] [ 84.967270][ T5322] but task is already holding lock: [ 84.970589][ T5322] ffff888040a08af8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 [ 84.974135][ T5322] [ 84.974135][ T5322] which lock already depends on the new lock. [ 84.974135][ T5322] [ 84.978513][ T5322] [ 84.978513][ T5322] the existing dependency chain (in reverse order) is: [ 84.982400][ T5322] [ 84.982400][ T5322] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 84.985575][ T5322] __mutex_lock+0x19f/0x1300 [ 84.987640][ T5322] l2cap_info_timeout+0x60/0xa0 [ 84.989972][ T5322] process_scheduled_works+0xb02/0x1830 [ 84.992658][ T5322] worker_thread+0xa50/0xfc0 [ 84.994901][ T5322] kthread+0x388/0x470 [ 84.996980][ T5322] ret_from_fork+0x51e/0xb90 [ 84.999339][ T5322] ret_from_fork_asm+0x1a/0x30 [ 85.001679][ T5322] [ 85.001679][ T5322] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 85.006158][ T5322] __lock_acquire+0x15a5/0x2cf0 [ 85.008519][ T5322] lock_acquire+0xf0/0x2e0 [ 85.010567][ T5322] __flush_work+0x700/0xc50 [ 85.012629][ T5322] __cancel_work_sync+0xbe/0x110 [ 85.014863][ T5322] l2cap_conn_del+0x40f/0x5c0 [ 85.017040][ T5322] hci_conn_hash_flush+0x10d/0x260 [ 85.019563][ T5322] hci_dev_close_sync+0x821/0x10e0 [ 85.022094][ T5322] hci_dev_close+0x108/0x260 [ 85.024353][ T5322] sock_do_ioctl+0x101/0x320 [ 85.026651][ T5322] sock_ioctl+0x5c6/0x7f0 [ 85.028832][ T5322] __se_sys_ioctl+0xfc/0x170 [ 85.031418][ T5322] do_syscall_64+0x14d/0xf80 [ 85.033617][ T5322] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.036501][ T5322] [ 85.036501][ T5322] other info that might help us debug this: [ 85.036501][ T5322] [ 85.041077][ T5322] Possible unsafe locking scenario: [ 85.041077][ T5322] [ 85.044198][ T5322] CPU0 CPU1 [ 85.046372][ T5322] ---- ---- [ 85.048651][ T5322] lock(&conn->lock#2); [ 85.050567][ T5322] lock((work_completion)(&(&conn->info_timer)->work)); [ 85.054566][ T5322] lock(&conn->lock#2); [ 85.057467][ T5322] lock((work_completion)(&(&conn->info_timer)->work)); [ 85.060295][ T5322] [ 85.060295][ T5322] *** DEADLOCK *** [ 85.060295][ T5322] [ 85.063598][ T5322] 5 locks held by syz.0.0/5322: [ 85.065651][ T5322] #0: ffff8880123e0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x260 [ 85.069588][ T5322] #1: ffff8880123e00c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 [ 85.073786][ T5322] #2: ffffffff8fd5a168 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 [ 85.078208][ T5322] #3: ffff888040a08af8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 [ 85.082478][ T5322] #4: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 [ 85.086680][ T5322] [ 85.086680][ T5322] stack backtrace: [ 85.089394][ T5322] CPU: 0 UID: 0 PID: 5322 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 85.089413][ T5322] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 85.089420][ T5322] Call Trace: [ 85.089428][ T5322] [ 85.089435][ T5322] dump_stack_lvl+0xe8/0x150 [ 85.089455][ T5322] print_circular_bug+0x2e1/0x300 [ 85.089475][ T5322] check_noncircular+0x12e/0x150 [ 85.089493][ T5322] __lock_acquire+0x15a5/0x2cf0 [ 85.089509][ T5322] ? do_raw_spin_lock+0x12b/0x2f0 [ 85.089522][ T5322] ? do_raw_spin_unlock+0x4d/0x210 [ 85.089534][ T5322] lock_acquire+0xf0/0x2e0 [ 85.089547][ T5322] ? __flush_work+0x100/0xc50 [ 85.089563][ T5322] ? __flush_work+0x100/0xc50 [ 85.089574][ T5322] __flush_work+0x700/0xc50 [ 85.089588][ T5322] ? __flush_work+0x100/0xc50 [ 85.089602][ T5322] ? __flush_work+0x100/0xc50 [ 85.089616][ T5322] ? __pfx___flush_work+0x10/0x10 [ 85.089632][ T5322] ? __pfx_wq_barrier_func+0x10/0x10 [ 85.089648][ T5322] ? __cancel_work_sync+0x5c/0x110 [ 85.089664][ T5322] __cancel_work_sync+0xbe/0x110 [ 85.089679][ T5322] l2cap_conn_del+0x40f/0x5c0 [ 85.089694][ T5322] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 85.089706][ T5322] hci_conn_hash_flush+0x10d/0x260 [ 85.089722][ T5322] hci_dev_close_sync+0x821/0x10e0 [ 85.089736][ T5322] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 85.089747][ T5322] ? lockdep_hardirqs_on+0x7a/0x110 [ 85.089762][ T5322] ? enable_work+0x1fd/0x230 [ 85.089779][ T5322] hci_dev_close+0x108/0x260 [ 85.089792][ T5322] sock_do_ioctl+0x101/0x320 [ 85.089811][ T5322] ? __pfx_sock_do_ioctl+0x10/0x10 [ 85.089825][ T5322] ? do_futex+0x395/0x420 [ 85.089842][ T5322] sock_ioctl+0x5c6/0x7f0 [ 85.089858][ T5322] ? __pfx_sock_ioctl+0x10/0x10 [ 85.089872][ T5322] ? __fget_files+0x2a/0x420 [ 85.089885][ T5322] ? __fget_files+0x3a0/0x420 [ 85.089897][ T5322] ? __fget_files+0x2a/0x420 [ 85.089910][ T5322] ? bpf_lsm_file_ioctl+0x9/0x20 [ 85.089922][ T5322] ? __pfx_sock_ioctl+0x10/0x10 [ 85.089937][ T5322] __se_sys_ioctl+0xfc/0x170 [ 85.090000][ T5322] do_syscall_64+0x14d/0xf80 [ 85.090014][ T5322] ? trace_irq_disable+0x3b/0x150 [ 85.090030][ T5322] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.090041][ T5322] ? clear_bhb_loop+0x40/0x90 [ 85.090053][ T5322] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.090066][ T5322] RIP: 0033:0x7fb8ba19c629 [ 85.090079][ T5322] 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 [ 85.090090][ T5322] RSP: 002b:00007fb8bb04a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 85.090104][ T5322] RAX: ffffffffffffffda RBX: 00007fb8ba415fa0 RCX: 00007fb8ba19c629 [ 85.090114][ T5322] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000006 [ 85.090121][ T5322] RBP: 00007fb8ba232b39 R08: 0000000000000000 R09: 0000000000000000 [ 85.090129][ T5322] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 85.090136][ T5322] R13: 00007fb8ba416038 R14: 00007fb8ba415fa0 R15: 00007ffc6c53f878 [ 85.090148][ T5322] [ 85.241199][ T5295] Bluetooth: hci0: command tx timeout [ 85.249237][ T5327] fido_id[5327]: Failed to open report descriptor at '/sys/devices/virtual/bluetooth/hci0/hci0:200/report_descriptor': No such file or directory [ 87.309852][ T5295] Bluetooth: hci0: command tx timeout [ 89.389811][ T5295] Bluetooth: hci0: command tx timeout