program: pipe(&(0x7f0000000040)={0xffffffffffffffff, 0xffffffffffffffff}) io_setup(0x3ff, &(0x7f0000000500)=0x0) writev(r0, &(0x7f0000000000)=[{&(0x7f00000000c0)="42e8", 0x2}], 0x1) io_submit(r1, 0x1, &(0x7f0000000300)=[&(0x7f0000000080)={0x0, 0x0, 0x0, 0x1, 0x0, r0, 0x0, 0xfe}]) r2 = syz_open_dev$tty1(0xc, 0x4, 0x1) ioctl$KDSETLED(r2, 0x4b32, 0x6) r3 = syz_init_net_socket$nfc_llcp(0x27, 0x1, 0x1) bind$nfc_llcp(r3, &(0x7f0000000240)={0x27, 0x0, 0x0, 0x0, 0x0, 0x0, "d9298498abdba7f061bd1ca44c226af5160e961711a07760760beeab11e88509de7f1939e8abff005597c8ef039a5be42200", 0x38}, 0x60) listen(r3, 0x0) prctl$PR_SET_MM_MAP(0x23, 0xe, &(0x7f0000000080)={&(0x7f0000ff0000/0x1000)=nil, &(0x7f0000ffd000/0x3000)=nil, &(0x7f0000ffc000/0x4000)=nil, &(0x7f0000ffc000/0x4000)=nil, &(0x7f0000ff8000/0x4000)=nil, &(0x7f0000ff8000/0x3000)=nil, &(0x7f0000ffb000/0x3000)=nil, &(0x7f0000ffb000/0x3000)=nil, &(0x7f0000ffc000/0x3000)=nil, &(0x7f0000ffa000/0x1000)=nil, &(0x7f0000ffa000/0x2000)=nil, 0x0}, 0x68) sendmsg$NFT_BATCH(0xffffffffffffffff, &(0x7f0000000080)={0x0, 0x0, 0x0}, 0x24004045) r4 = io_uring_setup(0x1b7b, &(0x7f0000000040)={0x0, 0xc89f, 0xc000, 0x0, 0x20002f7}) r5 = socket$inet(0x2, 0x80001, 0x84) getsockopt$inet_sctp_SCTP_MAX_BURST(r5, 0x84, 0x14, &(0x7f0000000000)=@assoc_value, &(0x7f0000000300)=0x8) ioctl$VIDIOC_TRY_FMT(0xffffffffffffffff, 0xc0d05640, &(0x7f0000000000)={0xd, @vbi={0x0, 0x0, 0x0, 0x4745504d, [], [0xfffffffe]}}) io_uring_enter(r4, 0x2219, 0x7721, 0x16, 0x0, 0x0) r6 = syz_init_net_socket$bt_l2cap(0x1f, 0x2, 0x0) connect$bt_l2cap(r6, &(0x7f0000000080)={0x1f, 0x0, @fixed={'\xaa\xaa\xaa\xaa\xaa', 0x10}, 0x7ff}, 0xe) r7 = syz_init_net_socket$bt_hidp(0x1f, 0x3, 0x6) ioctl$sock_bt_hidp_HIDPCONNADD(r7, 0x400448c8, &(0x7f00000000c0)={r6, r6, 0x206, 0x0, 0x0, 0x2, 0x72, 0x1, 0x3, 0x7, 0x0, 0x8, 'syz1\x00'}) r8 = syz_init_net_socket$bt_hci(0x1f, 0x3, 0x1) ioctl$HCIINQUIRY(r8, 0x400448ca, 0x0) [ 85.724718][ T5346] input: Bluetooth HID Boot Protocol Device as /devices/virtual/bluetooth/hci0/hci0:200/input5 [ 85.873960][ T4688] Bluetooth: hci0: command tx timeout [ 85.878967][ T5346] [ 85.880125][ T5346] ====================================================== [ 85.883156][ T5346] WARNING: possible circular locking dependency detected [ 85.886097][ T5346] syzkaller #0 Not tainted [ 85.888031][ T5346] ------------------------------------------------------ [ 85.891087][ T5346] syz.0.0/5346 is trying to acquire lock: [ 85.893522][ T5346] ffff888041663840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 [ 85.898554][ T5346] [ 85.898554][ T5346] but task is already holding lock: [ 85.901755][ T5346] ffff888041663b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 [ 85.905625][ T5346] [ 85.905625][ T5346] which lock already depends on the new lock. [ 85.905625][ T5346] [ 85.910059][ T5346] [ 85.910059][ T5346] the existing dependency chain (in reverse order) is: [ 85.913912][ T5346] [ 85.913912][ T5346] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 85.917257][ T5346] __mutex_lock+0x19f/0x1300 [ 85.919565][ T5346] l2cap_info_timeout+0x60/0xa0 [ 85.922024][ T5346] process_scheduled_works+0xaec/0x17a0 [ 85.924677][ T5346] worker_thread+0x89f/0xd90 [ 85.926994][ T5346] kthread+0x726/0x8b0 [ 85.929100][ T5346] ret_from_fork+0x51b/0xa40 [ 85.931383][ T5346] ret_from_fork_asm+0x1a/0x30 [ 85.933784][ T5346] [ 85.933784][ T5346] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 85.938236][ T5346] __lock_acquire+0x15a5/0x2cf0 [ 85.940661][ T5346] lock_acquire+0x106/0x330 [ 85.942918][ T5346] __flush_work+0x700/0xc50 [ 85.945217][ T5346] __cancel_work_sync+0xbe/0x110 [ 85.947593][ T5346] l2cap_conn_del+0x402/0x5b0 [ 85.949958][ T5346] hci_conn_hash_flush+0x10d/0x260 [ 85.952713][ T5346] hci_dev_close_sync+0x821/0x10e0 [ 85.955278][ T5346] hci_dev_close+0x108/0x260 [ 85.957668][ T5346] sock_do_ioctl+0x101/0x320 [ 85.959920][ T5346] sock_ioctl+0x5c6/0x7f0 [ 85.962071][ T5346] __se_sys_ioctl+0xfc/0x170 [ 85.964352][ T5346] do_syscall_64+0xe2/0xf80 [ 85.966550][ T5346] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.969075][ T5346] [ 85.969075][ T5346] other info that might help us debug this: [ 85.969075][ T5346] [ 85.973126][ T5346] Possible unsafe locking scenario: [ 85.973126][ T5346] [ 85.976168][ T5346] CPU0 CPU1 [ 85.978592][ T5346] ---- ---- [ 85.980998][ T5346] lock(&conn->lock#2); [ 85.982890][ T5346] lock((work_completion)(&(&conn->info_timer)->work)); [ 85.987069][ T5346] lock(&conn->lock#2); [ 85.990061][ T5346] lock((work_completion)(&(&conn->info_timer)->work)); [ 85.993160][ T5346] [ 85.993160][ T5346] *** DEADLOCK *** [ 85.993160][ T5346] [ 85.996671][ T5346] 5 locks held by syz.0.0/5346: [ 85.998910][ T5346] #0: ffff888011b40ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x260 [ 86.003080][ T5346] #1: ffff888011b400c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 [ 86.007310][ T5346] #2: ffffffff8f936fc8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 [ 86.011767][ T5346] #3: ffff888041663b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 [ 86.016100][ T5346] #4: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 [ 86.020261][ T5346] [ 86.020261][ T5346] stack backtrace: [ 86.023008][ T5346] CPU: 0 UID: 0 PID: 5346 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 86.023029][ T5346] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 86.023039][ T5346] Call Trace: [ 86.023049][ T5346] [ 86.023056][ T5346] dump_stack_lvl+0xe8/0x150 [ 86.023080][ T5346] print_circular_bug+0x2e1/0x300 [ 86.023097][ T5346] check_noncircular+0x12e/0x150 [ 86.023114][ T5346] __lock_acquire+0x15a5/0x2cf0 [ 86.023127][ T5346] ? do_raw_spin_lock+0x12b/0x2f0 [ 86.023146][ T5346] ? __flush_work+0x100/0xc50 [ 86.023157][ T5346] lock_acquire+0x106/0x330 [ 86.023169][ T5346] ? __flush_work+0x100/0xc50 [ 86.023184][ T5346] ? __flush_work+0x100/0xc50 [ 86.023197][ T5346] __flush_work+0x700/0xc50 [ 86.023211][ T5346] ? __flush_work+0x100/0xc50 [ 86.023226][ T5346] ? __flush_work+0x100/0xc50 [ 86.023239][ T5346] ? __pfx___flush_work+0x10/0x10 [ 86.023251][ T5346] ? __pfx_wq_barrier_func+0x10/0x10 [ 86.023267][ T5346] ? __cancel_work_sync+0x5c/0x110 [ 86.023280][ T5346] __cancel_work_sync+0xbe/0x110 [ 86.023293][ T5346] l2cap_conn_del+0x402/0x5b0 [ 86.023308][ T5346] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 86.023323][ T5346] hci_conn_hash_flush+0x10d/0x260 [ 86.023339][ T5346] hci_dev_close_sync+0x821/0x10e0 [ 86.023355][ T5346] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 86.023366][ T5346] ? lockdep_hardirqs_on+0x7a/0x110 [ 86.023380][ T5346] ? enable_work+0x1e9/0x220 [ 86.023393][ T5346] hci_dev_close+0x108/0x260 [ 86.023406][ T5346] sock_do_ioctl+0x101/0x320 [ 86.023420][ T5346] ? __pfx_sock_do_ioctl+0x10/0x10 [ 86.023429][ T5346] ? do_futex+0x395/0x420 [ 86.023444][ T5346] sock_ioctl+0x5c6/0x7f0 [ 86.023454][ T5346] ? __pfx_sock_ioctl+0x10/0x10 [ 86.023464][ T5346] ? __fget_files+0x2a/0x420 [ 86.023476][ T5346] ? __fget_files+0x3a0/0x420 [ 86.023486][ T5346] ? __fget_files+0x2a/0x420 [ 86.023498][ T5346] ? bpf_lsm_file_ioctl+0x9/0x20 [ 86.023509][ T5346] ? __pfx_sock_ioctl+0x10/0x10 [ 86.023518][ T5346] __se_sys_ioctl+0xfc/0x170 [ 86.023543][ T5346] do_syscall_64+0xe2/0xf80 [ 86.023562][ T5346] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 86.023573][ T5346] ? trace_irq_disable+0x37/0x100 [ 86.023591][ T5346] ? clear_bhb_loop+0x60/0xb0 [ 86.023604][ T5346] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 86.023617][ T5346] RIP: 0033:0x7f18ed99acb9 [ 86.023630][ T5346] 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 [ 86.023638][ T5346] RSP: 002b:00007f18ee7ea028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 86.023653][ T5346] RAX: ffffffffffffffda RBX: 00007f18edc15fa0 RCX: 00007f18ed99acb9 [ 86.023661][ T5346] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 000000000000000b [ 86.023668][ T5346] RBP: 00007f18eda08bf7 R08: 0000000000000000 R09: 0000000000000000 [ 86.023676][ T5346] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 86.023683][ T5346] R13: 00007f18edc16038 R14: 00007f18edc15fa0 R15: 00007ffe24040b68 [ 86.023697][ T5346] [ 87.953427][ T4688] Bluetooth: hci0: command tx timeout [ 90.035894][ T4688] Bluetooth: hci0: command tx timeout [ 91.559362][ T1399] cfg80211: failed to load regulatory.db