program: r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x2, 0x0) mkdir(&(0x7f0000000100)='./file0\x00', 0x0) mount(0x0, &(0x7f0000004580)='./file0\x00', &(0x7f0000000040)='ramfs\x00', 0x0, 0x0) chdir(&(0x7f0000000140)='./file0\x00') mkdir(&(0x7f0000000300)='./file0\x00', 0x0) mkdirat(0xffffffffffffff9c, &(0x7f0000000040)='./file1\x00', 0x0) mount(0x0, &(0x7f0000000180)='./file0\x00', &(0x7f0000000080)='sysfs\x00', 0x0, 0x0) mount$overlay(0x0, &(0x7f00000000c0)='./bus\x00', &(0x7f0000000080), 0x0, &(0x7f0000000400)={[{@workdir={'workdir', 0x3d, './bus'}}, {@lowerdir={'lowerdir', 0x3d, './file0'}}, {@upperdir={'upperdir', 0x3d, './file1'}}]}) 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$sock_bt_hidp_HIDPCONNADD(r1, 0x400448c8, &(0x7f0000000280)={r0, r0, 0xc, 0x0, 0x0, 0x9, 0x1, 0x457, 0x9, 0x9, 0x1, 0x1, 'syz1\x00'}) r2 = landlock_create_ruleset(&(0x7f00000002c0)={0x2000}, 0x18, 0x0) r3 = openat$dir(0xffffffffffffff9c, &(0x7f0000000300)='./file1\x00', 0x200000, 0x0) landlock_add_rule$LANDLOCK_RULE_PATH_BENEATH(r2, 0x1, &(0x7f0000000340)={0x2000, r3}, 0x0) mkdirat(r3, &(0x7f0000000000)='./file1\x00', 0x101) r4 = syz_init_net_socket$bt_hci(0x1f, 0x3, 0x1) ioctl$sock_bt_hci(r4, 0x400448ca, 0x0) [ 85.693712][ T5310] Bluetooth: hci0: command tx timeout [ 85.856069][ T5334] input: Bluetooth HID Boot Protocol Device as /devices/virtual/bluetooth/hci0/hci0:200/input5 [ 85.933151][ T5335] [ 85.934445][ T5335] ====================================================== [ 85.937546][ T5335] WARNING: possible circular locking dependency detected [ 85.940795][ T5335] 6.16.0-syzkaller-04405-g4b290aae788e #0 Not tainted [ 85.944019][ T5335] ------------------------------------------------------ [ 85.947650][ T5335] syz.0.0/5335 is trying to acquire lock: [ 85.950051][ T5335] ffff888045f37040 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0xd2/0xbc0 [ 85.955306][ T5335] [ 85.955306][ T5335] but task is already holding lock: [ 85.958541][ T5335] ffff888045f37338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 [ 85.962584][ T5335] [ 85.962584][ T5335] which lock already depends on the new lock. [ 85.962584][ T5335] [ 85.967167][ T5335] [ 85.967167][ T5335] the existing dependency chain (in reverse order) is: [ 85.971369][ T5335] [ 85.971369][ T5335] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 85.975146][ T5335] lock_acquire+0x120/0x360 [ 85.977656][ T5335] __mutex_lock+0x187/0x1340 [ 85.979919][ T5335] l2cap_info_timeout+0x60/0xa0 [ 85.982308][ T5335] process_scheduled_works+0xade/0x17b0 [ 85.985003][ T5335] worker_thread+0x8a0/0xda0 [ 85.987283][ T5335] kthread+0x711/0x8a0 [ 85.989390][ T5335] ret_from_fork+0x3fc/0x770 [ 85.991808][ T5335] ret_from_fork_asm+0x1a/0x30 [ 85.994409][ T5335] [ 85.994409][ T5335] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 85.999049][ T5335] validate_chain+0xb9b/0x2140 [ 86.001585][ T5335] __lock_acquire+0xab9/0xd20 [ 86.003895][ T5335] lock_acquire+0x120/0x360 [ 86.006269][ T5335] __flush_work+0x6b8/0xbc0 [ 86.008690][ T5335] __cancel_work_sync+0xbe/0x110 [ 86.011072][ T5335] l2cap_conn_del+0x4f0/0x680 [ 86.013364][ T5335] hci_conn_hash_flush+0x10d/0x230 [ 86.016052][ T5335] hci_dev_close_sync+0xaef/0x1330 [ 86.018932][ T5335] hci_dev_close+0x108/0x200 [ 86.021841][ T5335] sock_do_ioctl+0xdc/0x300 [ 86.024110][ T5335] sock_ioctl+0x576/0x790 [ 86.026322][ T5335] __se_sys_ioctl+0xf9/0x170 [ 86.028674][ T5335] do_syscall_64+0xfa/0x3b0 [ 86.030909][ T5335] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 86.033642][ T5335] [ 86.033642][ T5335] other info that might help us debug this: [ 86.033642][ T5335] [ 86.038065][ T5335] Possible unsafe locking scenario: [ 86.038065][ T5335] [ 86.041761][ T5335] CPU0 CPU1 [ 86.044367][ T5335] ---- ---- [ 86.046794][ T5335] lock(&conn->lock#2); [ 86.048686][ T5335] lock((work_completion)(&(&conn->info_timer)->work)); [ 86.053620][ T5335] lock(&conn->lock#2); [ 86.057156][ T5335] lock((work_completion)(&(&conn->info_timer)->work)); [ 86.059687][ T5335] [ 86.059687][ T5335] *** DEADLOCK *** [ 86.059687][ T5335] [ 86.063214][ T5335] 5 locks held by syz.0.0/5335: [ 86.065390][ T5335] #0: ffff88803294cdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x200 [ 86.070133][ T5335] #1: ffff88803294c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 [ 86.074277][ T5335] #2: ffffffff8f66e748 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 [ 86.078672][ T5335] #3: ffff888045f37338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 [ 86.084238][ T5335] #4: ffffffff8e13c520 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xd2/0xbc0 [ 86.088803][ T5335] [ 86.088803][ T5335] stack backtrace: [ 86.091721][ T5335] CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.16.0-syzkaller-04405-g4b290aae788e #0 PREEMPT(full) [ 86.091739][ T5335] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 [ 86.091746][ T5335] Call Trace: [ 86.091755][ T5335] [ 86.091763][ T5335] dump_stack_lvl+0x189/0x250 [ 86.091782][ T5335] ? __pfx_dump_stack_lvl+0x10/0x10 [ 86.091794][ T5335] ? __pfx__printk+0x10/0x10 [ 86.091813][ T5335] ? print_lock_name+0xde/0x100 [ 86.091829][ T5335] print_circular_bug+0x2ee/0x310 [ 86.091843][ T5335] check_noncircular+0x134/0x160 [ 86.091858][ T5335] validate_chain+0xb9b/0x2140 [ 86.091875][ T5335] ? do_raw_spin_lock+0x121/0x290 [ 86.091892][ T5335] ? look_up_lock_class+0x74/0x170 [ 86.091907][ T5335] ? register_lock_class+0x51/0x320 [ 86.091926][ T5335] __lock_acquire+0xab9/0xd20 [ 86.091942][ T5335] ? __flush_work+0xd2/0xbc0 [ 86.091954][ T5335] lock_acquire+0x120/0x360 [ 86.091968][ T5335] ? __flush_work+0xd2/0xbc0 [ 86.091979][ T5335] ? _raw_spin_unlock_irq+0x23/0x50 [ 86.091990][ T5335] ? __flush_work+0xd2/0xbc0 [ 86.092000][ T5335] __flush_work+0x6b8/0xbc0 [ 86.092010][ T5335] ? __flush_work+0xd2/0xbc0 [ 86.092021][ T5335] ? __flush_work+0xd2/0xbc0 [ 86.092032][ T5335] ? __pfx___flush_work+0x10/0x10 [ 86.092044][ T5335] ? __pfx_wq_barrier_func+0x10/0x10 [ 86.092056][ T5335] ? __pfx___cancel_work+0x10/0x10 [ 86.092068][ T5335] ? hci_conn_drop+0x14d/0x280 [ 86.092079][ T5335] __cancel_work_sync+0xbe/0x110 [ 86.092091][ T5335] l2cap_conn_del+0x4f0/0x680 [ 86.092103][ T5335] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 86.092113][ T5335] hci_conn_hash_flush+0x10d/0x230 [ 86.092125][ T5335] hci_dev_close_sync+0xaef/0x1330 [ 86.092143][ T5335] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 86.092157][ T5335] ? do_raw_read_unlock+0x3d/0x80 [ 86.092170][ T5335] hci_dev_close+0x108/0x200 [ 86.092187][ T5335] sock_do_ioctl+0xdc/0x300 [ 86.092201][ T5335] ? __pfx_sock_do_ioctl+0x10/0x10 [ 86.092212][ T5335] ? __lock_acquire+0xab9/0xd20 [ 86.092230][ T5335] sock_ioctl+0x576/0x790 [ 86.092243][ T5335] ? __pfx_sock_ioctl+0x10/0x10 [ 86.092253][ T5335] ? __fget_files+0x2a/0x420 [ 86.092266][ T5335] ? __fget_files+0x3a0/0x420 [ 86.092277][ T5335] ? __fget_files+0x2a/0x420 [ 86.092288][ T5335] ? bpf_lsm_file_ioctl+0x9/0x20 [ 86.092299][ T5335] ? __pfx_sock_ioctl+0x10/0x10 [ 86.092310][ T5335] __se_sys_ioctl+0xf9/0x170 [ 86.092321][ T5335] do_syscall_64+0xfa/0x3b0 [ 86.092335][ T5335] ? lockdep_hardirqs_on+0x9c/0x150 [ 86.092346][ T5335] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 86.092357][ T5335] ? clear_bhb_loop+0x60/0xb0 [ 86.092369][ T5335] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 86.092379][ T5335] RIP: 0033:0x7f69dcf8e9a9 [ 86.092390][ T5335] 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 [ 86.092399][ T5335] RSP: 002b:00007f69ddd99038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 86.092411][ T5335] RAX: ffffffffffffffda RBX: 00007f69dd1b6080 RCX: 00007f69dcf8e9a9 [ 86.092420][ T5335] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000008 [ 86.092429][ T5335] RBP: 00007f69dd010d69 R08: 0000000000000000 R09: 0000000000000000 [ 86.092436][ T5335] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 86.092442][ T5335] R13: 0000000000000000 R14: 00007f69dd1b6080 R15: 00007ffd1ce90dd8 [ 86.092454][ T5335] [ 86.634233][ T54] cfg80211: failed to load regulatory.db [ 87.752632][ T4676] Bluetooth: hci0: command tx timeout [ 89.833734][ T4676] Bluetooth: hci0: command tx timeout [ 91.912428][ T4676] Bluetooth: hci0: command tx timeout