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) syz_mount_image$ext4(&(0x7f0000000500)='ext4\x00', &(0x7f0000000480)='./file0\x00', 0x0, &(0x7f00000004c0)={[{}]}, 0x1, 0x453, &(0x7f0000001040)="$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") r4 = openat$cgroup_ro(0xffffffffffffff9c, &(0x7f0000000140)='cgroup.controllers\x00', 0x275a, 0x0) ioctl$FS_IOC_SETFLAGS(r4, 0x40086602, &(0x7f00000002c0)=0x2000000) write$cgroup_int(r4, &(0x7f0000000040)=0x7, 0x3f) close(r4) sync() openat$cgroup_ro(0xffffffffffffff9c, &(0x7f0000000080)='cgroup.controllers\x00', 0x275a, 0x0) syz_open_dev$tty1(0xc, 0x4, 0x1) (async) ioctl$KDSETLED(r0, 0x4b32, 0x6) (async) syz_init_net_socket$bt_l2cap(0x1f, 0x2, 0x0) (async) connect$bt_l2cap(r1, &(0x7f0000000080)={0x1f, 0x0, @fixed={'\xaa\xaa\xaa\xaa\xaa', 0x10}, 0x7ff}, 0xe) (async) syz_init_net_socket$bt_hidp(0x1f, 0x3, 0x6) (async) ioctl$sock_bt_hidp_HIDPCONNADD(r2, 0x400448c8, &(0x7f00000000c0)={r1, r1, 0x206, 0x0, 0x0, 0x2, 0x72, 0x1, 0x3, 0x7, 0x0, 0x8, 'syz1\x00'}) (async) syz_init_net_socket$bt_hci(0x1f, 0x3, 0x1) (async) ioctl$sock_bt_hci(r3, 0x400448ca, 0x0) (async) syz_mount_image$ext4(&(0x7f0000000500)='ext4\x00', &(0x7f0000000480)='./file0\x00', 0x0, &(0x7f00000004c0)={[{}]}, 0x1, 0x453, &(0x7f0000001040)="$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") (async) openat$cgroup_ro(0xffffffffffffff9c, &(0x7f0000000140)='cgroup.controllers\x00', 0x275a, 0x0) (async) ioctl$FS_IOC_SETFLAGS(r4, 0x40086602, &(0x7f00000002c0)=0x2000000) (async) write$cgroup_int(r4, &(0x7f0000000040)=0x7, 0x3f) (async) close(r4) (async) sync() (async) openat$cgroup_ro(0xffffffffffffff9c, &(0x7f0000000080)='cgroup.controllers\x00', 0x275a, 0x0) (async) [ 88.315429][ T5323] input: Bluetooth HID Boot Protocol Device as /devices/virtual/bluetooth/hci0/hci0:200/input5 [ 88.495987][ T5331] loop0: detected capacity change from 0 to 512 [ 88.616733][ T5331] EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. [ 88.753903][ T4665] Bluetooth: hci0: command tx timeout [ 88.791733][ T5325] [ 88.793084][ T5325] ====================================================== [ 88.796382][ T5325] WARNING: possible circular locking dependency detected [ 88.799336][ T5325] syzkaller #0 Not tainted [ 88.801213][ T5325] ------------------------------------------------------ [ 88.804280][ T5325] syz.0.0/5325 is trying to acquire lock: [ 88.807100][ T5325] ffff888044b6b840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0xd2/0xbc0 [ 88.812909][ T5325] [ 88.812909][ T5325] but task is already holding lock: [ 88.816479][ T5325] ffff888044b6bb38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 [ 88.820984][ T5325] [ 88.820984][ T5325] which lock already depends on the new lock. [ 88.820984][ T5325] [ 88.825315][ T5325] [ 88.825315][ T5325] the existing dependency chain (in reverse order) is: [ 88.828828][ T5325] [ 88.828828][ T5325] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 88.831647][ T5325] lock_acquire+0x120/0x360 [ 88.833586][ T5325] __mutex_lock+0x187/0x1350 [ 88.835711][ T5325] l2cap_info_timeout+0x60/0xa0 [ 88.838020][ T5325] process_scheduled_works+0xae1/0x17b0 [ 88.840748][ T5325] worker_thread+0x8a0/0xda0 [ 88.843020][ T5325] kthread+0x711/0x8a0 [ 88.845088][ T5325] ret_from_fork+0x4bc/0x870 [ 88.847309][ T5325] ret_from_fork_asm+0x1a/0x30 [ 88.849626][ T5325] [ 88.849626][ T5325] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 88.853890][ T5325] validate_chain+0xb9b/0x2140 [ 88.856789][ T5325] __lock_acquire+0xab9/0xd20 [ 88.859281][ T5325] lock_acquire+0x120/0x360 [ 88.861410][ T5325] __flush_work+0x6b8/0xbc0 [ 88.863616][ T5325] __cancel_work_sync+0xbe/0x110 [ 88.865994][ T5325] l2cap_conn_del+0x4f0/0x680 [ 88.868029][ T5325] hci_conn_hash_flush+0x10a/0x230 [ 88.870130][ T5325] hci_dev_close_sync+0xaef/0x1330 [ 88.872409][ T5325] hci_dev_close+0x108/0x200 [ 88.874707][ T5325] sock_do_ioctl+0xdc/0x300 [ 88.876995][ T5325] sock_ioctl+0x576/0x790 [ 88.879083][ T5325] __se_sys_ioctl+0xfc/0x170 [ 88.881217][ T5325] do_syscall_64+0xfa/0xfa0 [ 88.883263][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 88.885881][ T5325] [ 88.885881][ T5325] other info that might help us debug this: [ 88.885881][ T5325] [ 88.890013][ T5325] Possible unsafe locking scenario: [ 88.890013][ T5325] [ 88.892944][ T5325] CPU0 CPU1 [ 88.895102][ T5325] ---- ---- [ 88.897238][ T5325] lock(&conn->lock#2); [ 88.899015][ T5325] lock((work_completion)(&(&conn->info_timer)->work)); [ 88.903101][ T5325] lock(&conn->lock#2); [ 88.905989][ T5325] lock((work_completion)(&(&conn->info_timer)->work)); [ 88.908998][ T5325] [ 88.908998][ T5325] *** DEADLOCK *** [ 88.908998][ T5325] [ 88.912593][ T5325] 5 locks held by syz.0.0/5325: [ 88.914798][ T5325] #0: ffff88803b8d0dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x200 [ 88.918703][ T5325] #1: ffff88803b8d00b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 [ 88.922487][ T5325] #2: ffffffff8f64ac28 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 [ 88.927862][ T5325] #3: ffff888044b6bb38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 [ 88.931869][ T5325] #4: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xd2/0xbc0 [ 88.935809][ T5325] [ 88.935809][ T5325] stack backtrace: [ 88.938396][ T5325] CPU: 0 UID: 0 PID: 5325 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 88.938409][ T5325] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 [ 88.938415][ T5325] Call Trace: [ 88.938421][ T5325] [ 88.938426][ T5325] dump_stack_lvl+0x189/0x250 [ 88.938441][ T5325] ? __pfx_dump_stack_lvl+0x10/0x10 [ 88.938451][ T5325] ? __pfx__printk+0x10/0x10 [ 88.938462][ T5325] ? print_lock_name+0xde/0x100 [ 88.938472][ T5325] print_circular_bug+0x2ee/0x310 [ 88.938487][ T5325] check_noncircular+0x134/0x160 [ 88.938500][ T5325] validate_chain+0xb9b/0x2140 [ 88.938511][ T5325] ? do_raw_spin_lock+0x121/0x290 [ 88.938524][ T5325] ? look_up_lock_class+0x74/0x170 [ 88.938538][ T5325] ? register_lock_class+0x51/0x320 [ 88.938548][ T5325] __lock_acquire+0xab9/0xd20 [ 88.938558][ T5325] ? __flush_work+0xd2/0xbc0 [ 88.938570][ T5325] lock_acquire+0x120/0x360 [ 88.938579][ T5325] ? __flush_work+0xd2/0xbc0 [ 88.938590][ T5325] ? _raw_spin_unlock_irq+0x23/0x50 [ 88.938602][ T5325] ? __flush_work+0xd2/0xbc0 [ 88.938619][ T5325] __flush_work+0x6b8/0xbc0 [ 88.938629][ T5325] ? __flush_work+0xd2/0xbc0 [ 88.938639][ T5325] ? __flush_work+0xd2/0xbc0 [ 88.938650][ T5325] ? __pfx___flush_work+0x10/0x10 [ 88.938660][ T5325] ? __pfx_wq_barrier_func+0x10/0x10 [ 88.938672][ T5325] ? __pfx___cancel_work+0x10/0x10 [ 88.938683][ T5325] ? hci_conn_drop+0x14d/0x280 [ 88.938699][ T5325] __cancel_work_sync+0xbe/0x110 [ 88.938711][ T5325] l2cap_conn_del+0x4f0/0x680 [ 88.938725][ T5325] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 88.938736][ T5325] hci_conn_hash_flush+0x10a/0x230 [ 88.938752][ T5325] hci_dev_close_sync+0xaef/0x1330 [ 88.938765][ T5325] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 88.938776][ T5325] ? do_raw_read_unlock+0x3d/0x80 [ 88.938789][ T5325] hci_dev_close+0x108/0x200 [ 88.938803][ T5325] sock_do_ioctl+0xdc/0x300 [ 88.938817][ T5325] ? __pfx_sock_do_ioctl+0x10/0x10 [ 88.938830][ T5325] sock_ioctl+0x576/0x790 [ 88.938840][ T5325] ? __pfx_sock_ioctl+0x10/0x10 [ 88.938852][ T5325] ? __fget_files+0x3a0/0x420 [ 88.938864][ T5325] ? __fget_files+0x2a/0x420 [ 88.938875][ T5325] ? bpf_lsm_file_ioctl+0x9/0x20 [ 88.938884][ T5325] ? __pfx_sock_ioctl+0x10/0x10 [ 88.938894][ T5325] __se_sys_ioctl+0xfc/0x170 [ 88.938905][ T5325] do_syscall_64+0xfa/0xfa0 [ 88.938917][ T5325] ? lockdep_hardirqs_on+0x9c/0x150 [ 88.938927][ T5325] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 88.938937][ T5325] ? clear_bhb_loop+0x60/0xb0 [ 88.938946][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 88.938955][ T5325] RIP: 0033:0x7fe13098eec9 [ 88.938966][ T5325] 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 [ 88.938975][ T5325] RSP: 002b:00007fe13181c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 88.939012][ T5325] RAX: ffffffffffffffda RBX: 00007fe130be6090 RCX: 00007fe13098eec9 [ 88.939020][ T5325] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000007 [ 88.939026][ T5325] RBP: 00007fe130a11f91 R08: 0000000000000000 R09: 0000000000000000 [ 88.939031][ T5325] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 88.939037][ T5325] R13: 00007fe130be6128 R14: 00007fe130be6090 R15: 00007ffd37f94d18 [ 88.939047][ T5325] [ 90.829923][ T5302] Bluetooth: hci0: command tx timeout [ 91.880502][ T9] cfg80211: failed to load regulatory.db [ 92.910264][ T5302] Bluetooth: hci0: command tx timeout