program: r0 = syz_open_dev$tty1(0xc, 0x4, 0x1) ioctl$KDSETLED(r0, 0x4b32, 0x6) r1 = syz_init_net_socket$bt_l2cap(0x1f, 0x2, 0x0) connect$bt_l2cap(r1, &(0x7f0000000080)={0x1f, 0x0, @fixed={'\xaa\xaa\xaa\xaa\xaa', 0x10}, 0x7ff}, 0xe) r2 = syz_init_net_socket$bt_hidp(0x1f, 0x3, 0x6) ioctl$sock_bt_hidp_HIDPCONNADD(r2, 0x400448c8, &(0x7f00000000c0)={r1, r1, 0x206, 0x0, 0x0, 0x2, 0x72, 0x1, 0x3, 0x7, 0x0, 0x8, 'syz1\x00'}) r3 = syz_init_net_socket$bt_hci(0x1f, 0x3, 0x1) ioctl$sock_bt_hci(r3, 0x400448ca, 0x0) r4 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0xa, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x0, 0x7fc00100}]}) openat$dir(0xffffffffffffff9c, 0x0, 0x0, 0x0) ioctl$SECCOMP_IOCTL_NOTIF_RECV(r4, 0xc0502100, &(0x7f00000002c0)={0x0}) ioctl$SECCOMP_IOCTL_NOTIF_SEND(r4, 0xc0182101, &(0x7f0000000200)={r5}) ioctl$SECCOMP_IOCTL_NOTIF_RECV(r4, 0xc0502100, &(0x7f0000000180)={0x0}) r7 = socket$inet6_udplite(0xa, 0x2, 0x88) ioctl$SECCOMP_IOCTL_NOTIF_ADDFD(r4, 0x40182103, &(0x7f0000000240)={r6, 0x3, r7, 0xffffffff}) ioctl$SECCOMP_IOCTL_NOTIF_SEND(r4, 0xc0182101, &(0x7f0000000280)={r6}) [ 86.715765][ T5329] input: Bluetooth HID Boot Protocol Device as /devices/virtual/bluetooth/hci0/hci0:200/input5 [ 86.765547][ T9] cfg80211: failed to load regulatory.db [ 86.849495][ T5330] [ 86.850539][ T5330] ====================================================== [ 86.853549][ T5330] WARNING: possible circular locking dependency detected [ 86.856472][ T5330] syzkaller #0 Not tainted [ 86.858611][ T5330] ------------------------------------------------------ [ 86.861817][ T5330] syz.0.0/5330 is trying to acquire lock: [ 86.864602][ T5330] ffff88801157a040 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0xd2/0xbc0 [ 86.869674][ T5330] [ 86.869674][ T5330] but task is already holding lock: [ 86.873023][ T5330] ffff88801157a338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 [ 86.877032][ T5330] [ 86.877032][ T5330] which lock already depends on the new lock. [ 86.877032][ T5330] [ 86.881862][ T5330] [ 86.881862][ T5330] the existing dependency chain (in reverse order) is: [ 86.885992][ T5330] [ 86.885992][ T5330] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 86.889302][ T5330] lock_acquire+0x120/0x360 [ 86.891965][ T5330] __mutex_lock+0x187/0x1350 [ 86.894290][ T5330] l2cap_info_timeout+0x60/0xa0 [ 86.896634][ T5330] process_scheduled_works+0xae1/0x17b0 [ 86.899595][ T5330] worker_thread+0x8a0/0xda0 [ 86.901890][ T5330] kthread+0x711/0x8a0 [ 86.904011][ T5330] ret_from_fork+0x4bc/0x870 [ 86.906385][ T5330] ret_from_fork_asm+0x1a/0x30 [ 86.908835][ T5330] [ 86.908835][ T5330] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 86.913449][ T5330] validate_chain+0xb9b/0x2140 [ 86.915845][ T5330] __lock_acquire+0xab9/0xd20 [ 86.918247][ T5330] lock_acquire+0x120/0x360 [ 86.920504][ T5330] __flush_work+0x6b8/0xbc0 [ 86.922830][ T5330] __cancel_work_sync+0xbe/0x110 [ 86.925289][ T5330] l2cap_conn_del+0x4f0/0x680 [ 86.927758][ T5330] hci_conn_hash_flush+0x10d/0x230 [ 86.930286][ T5330] hci_dev_close_sync+0xaef/0x1330 [ 86.932873][ T5330] hci_dev_close+0x108/0x200 [ 86.935163][ T5330] sock_do_ioctl+0xdc/0x300 [ 86.937609][ T5330] sock_ioctl+0x576/0x790 [ 86.939929][ T5330] __se_sys_ioctl+0xfc/0x170 [ 86.942224][ T5330] do_syscall_64+0xfa/0xfa0 [ 86.944491][ T5330] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 86.947520][ T5330] [ 86.947520][ T5330] other info that might help us debug this: [ 86.947520][ T5330] [ 86.952027][ T5330] Possible unsafe locking scenario: [ 86.952027][ T5330] [ 86.955086][ T5330] CPU0 CPU1 [ 86.957250][ T5330] ---- ---- [ 86.959477][ T5330] lock(&conn->lock#2); [ 86.961220][ T5330] lock((work_completion)(&(&conn->info_timer)->work)); [ 86.965057][ T5330] lock(&conn->lock#2); [ 86.967924][ T5330] lock((work_completion)(&(&conn->info_timer)->work)); [ 86.970859][ T5330] [ 86.970859][ T5330] *** DEADLOCK *** [ 86.970859][ T5330] [ 86.974359][ T5330] 5 locks held by syz.0.0/5330: [ 86.976549][ T5330] #0: ffff88800039cdc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x200 [ 86.980739][ T5330] #1: ffff88800039c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 [ 86.984881][ T5330] #2: ffffffff8f437268 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 [ 86.989333][ T5330] #3: ffff88801157a338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 [ 86.993613][ T5330] #4: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xd2/0xbc0 [ 86.997437][ T5330] [ 86.997437][ T5330] stack backtrace: [ 86.999869][ T5330] CPU: 0 UID: 0 PID: 5330 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 86.999886][ T5330] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 [ 86.999894][ T5330] Call Trace: [ 86.999902][ T5330] [ 86.999909][ T5330] dump_stack_lvl+0x189/0x250 [ 86.999931][ T5330] ? __pfx_dump_stack_lvl+0x10/0x10 [ 86.999948][ T5330] ? __pfx__printk+0x10/0x10 [ 86.999963][ T5330] ? print_lock_name+0xde/0x100 [ 86.999974][ T5330] print_circular_bug+0x2ee/0x310 [ 86.999991][ T5330] check_noncircular+0x134/0x160 [ 87.000006][ T5330] validate_chain+0xb9b/0x2140 [ 87.000019][ T5330] ? do_raw_spin_lock+0x121/0x290 [ 87.000035][ T5330] ? look_up_lock_class+0x74/0x170 [ 87.000049][ T5330] ? register_lock_class+0x51/0x320 [ 87.000060][ T5330] __lock_acquire+0xab9/0xd20 [ 87.000072][ T5330] ? __flush_work+0xd2/0xbc0 [ 87.000086][ T5330] lock_acquire+0x120/0x360 [ 87.000096][ T5330] ? __flush_work+0xd2/0xbc0 [ 87.000111][ T5330] ? _raw_spin_unlock_irq+0x23/0x50 [ 87.000123][ T5330] ? __flush_work+0xd2/0xbc0 [ 87.000137][ T5330] __flush_work+0x6b8/0xbc0 [ 87.000150][ T5330] ? __flush_work+0xd2/0xbc0 [ 87.000162][ T5330] ? __flush_work+0xd2/0xbc0 [ 87.000175][ T5330] ? __pfx___flush_work+0x10/0x10 [ 87.000189][ T5330] ? __pfx_wq_barrier_func+0x10/0x10 [ 87.000204][ T5330] ? __pfx___cancel_work+0x10/0x10 [ 87.000219][ T5330] ? hci_conn_drop+0x14d/0x280 [ 87.000232][ T5330] __cancel_work_sync+0xbe/0x110 [ 87.000246][ T5330] l2cap_conn_del+0x4f0/0x680 [ 87.000263][ T5330] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 87.000279][ T5330] hci_conn_hash_flush+0x10d/0x230 [ 87.000297][ T5330] hci_dev_close_sync+0xaef/0x1330 [ 87.000314][ T5330] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 87.000329][ T5330] ? do_raw_read_unlock+0x3d/0x80 [ 87.000345][ T5330] hci_dev_close+0x108/0x200 [ 87.000360][ T5330] sock_do_ioctl+0xdc/0x300 [ 87.000373][ T5330] ? __pfx_sock_do_ioctl+0x10/0x10 [ 87.000388][ T5330] sock_ioctl+0x576/0x790 [ 87.000401][ T5330] ? __pfx_sock_ioctl+0x10/0x10 [ 87.000421][ T5330] ? __fget_files+0x3a0/0x420 [ 87.000441][ T5330] ? __fget_files+0x2a/0x420 [ 87.000458][ T5330] ? bpf_lsm_file_ioctl+0x9/0x20 [ 87.000469][ T5330] ? __pfx_sock_ioctl+0x10/0x10 [ 87.000481][ T5330] __se_sys_ioctl+0xfc/0x170 [ 87.000496][ T5330] do_syscall_64+0xfa/0xfa0 [ 87.000509][ T5330] ? lockdep_hardirqs_on+0x9c/0x150 [ 87.000522][ T5330] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.000533][ T5330] ? clear_bhb_loop+0x60/0xb0 [ 87.000545][ T5330] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.000557][ T5330] RIP: 0033:0x7fcf5378efc9 [ 87.000569][ T5330] Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 [ 87.000581][ T5330] RSP: 002b:00007fcf5453e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 87.000594][ T5330] RAX: ffffffffffffffda RBX: 00007fcf539e6090 RCX: 00007fcf5378efc9 [ 87.000603][ T5330] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000007 [ 87.000610][ T5330] RBP: 00007fcf53811f91 R08: 0000000000000000 R09: 0000000000000000 [ 87.000617][ T5330] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 87.000624][ T5330] R13: 00007fcf539e6128 R14: 00007fcf539e6090 R15: 00007ffdf067cb98 [ 87.000636][ T5330] [ 87.158967][ T4670] Bluetooth: hci0: command tx timeout [ 87.238341][ T25] audit: type=1326 audit(1761149159.864:2): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 87.247407][ T5334] UDPLite6: UDP-Lite is deprecated and scheduled to be removed in 2025, please contact the netdev mailing list [ 87.279977][ T25] audit: type=1326 audit(1761149159.884:3): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=257 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 87.505611][ T25] audit: type=1326 audit(1761149160.134:4): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 87.519786][ T25] audit: type=1326 audit(1761149160.154:5): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 87.532798][ T25] audit: type=1326 audit(1761149160.154:6): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 87.550805][ T25] audit: type=1326 audit(1761149160.154:7): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 87.561808][ T25] audit: type=1326 audit(1761149160.154:8): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 87.571789][ T25] audit: type=1326 audit(1761149160.154:9): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 87.579932][ T25] audit: type=1326 audit(1761149160.154:10): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 87.588736][ T25] audit: type=1326 audit(1761149160.154:11): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined pid=5328 comm="syz.0.0" exe="/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fcf5378efc9 code=0x7fc00000 [ 89.237978][ T4670] Bluetooth: hci0: command tx timeout [ 91.318011][ T4670] Bluetooth: hci0: command tx timeout