[ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. [ OK ] Started OpenBSD Secure Shell server. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.13' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 54.898770][ T7302] [ 54.901144][ T7302] ====================================================== [ 54.908192][ T7302] WARNING: possible circular locking dependency detected [ 54.915200][ T7302] 5.14.0-syzkaller #0 Not tainted [ 54.920224][ T7302] ------------------------------------------------------ [ 54.927230][ T7302] iou-sqp-7301/7302 is trying to acquire lock: [ 54.933373][ T7302] ffff8880761080a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_sq_thread+0x92c/0x12a0 [ 54.942562][ T7302] [ 54.942562][ T7302] but task is already holding lock: [ 54.950077][ T7302] ffff88801b509c70 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread+0x299/0x12a0 [ 54.958668][ T7302] [ 54.958668][ T7302] which lock already depends on the new lock. [ 54.958668][ T7302] [ 54.969067][ T7302] [ 54.969067][ T7302] the existing dependency chain (in reverse order) is: [ 54.978069][ T7302] [ 54.978069][ T7302] -> #1 (&sqd->lock){+.+.}-{3:3}: [ 54.985362][ T7302] lock_acquire+0x19f/0x4d0 [ 54.990548][ T7302] __mutex_lock_common+0x1df/0x2550 [ 54.996305][ T7302] mutex_lock_nested+0x1a/0x20 [ 55.001764][ T7302] __se_sys_io_uring_register+0x231e/0x3140 [ 55.008984][ T7302] do_syscall_64+0x44/0xd0 [ 55.015051][ T7302] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 55.024345][ T7302] [ 55.024345][ T7302] -> #0 (&ctx->uring_lock){+.+.}-{3:3}: [ 55.032551][ T7302] validate_chain+0x1dfb/0x8240 [ 55.038619][ T7302] __lock_acquire+0x1382/0x2b00 [ 55.043986][ T7302] lock_acquire+0x19f/0x4d0 [ 55.049111][ T7302] __mutex_lock_common+0x1df/0x2550 [ 55.055836][ T7302] mutex_lock_nested+0x1a/0x20 [ 55.061385][ T7302] io_sq_thread+0x92c/0x12a0 [ 55.067111][ T7302] ret_from_fork+0x1f/0x30 [ 55.072119][ T7302] [ 55.072119][ T7302] other info that might help us debug this: [ 55.072119][ T7302] [ 55.082686][ T7302] Possible unsafe locking scenario: [ 55.082686][ T7302] [ 55.090388][ T7302] CPU0 CPU1 [ 55.095970][ T7302] ---- ---- [ 55.101403][ T7302] lock(&sqd->lock); [ 55.105383][ T7302] lock(&ctx->uring_lock); [ 55.112505][ T7302] lock(&sqd->lock); [ 55.118988][ T7302] lock(&ctx->uring_lock); [ 55.123503][ T7302] [ 55.123503][ T7302] *** DEADLOCK *** [ 55.123503][ T7302] [ 55.131632][ T7302] 1 lock held by iou-sqp-7301/7302: [ 55.136914][ T7302] #0: ffff88801b509c70 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread+0x299/0x12a0 [ 55.146817][ T7302] [ 55.146817][ T7302] stack backtrace: [ 55.152773][ T7302] CPU: 1 PID: 7302 Comm: iou-sqp-7301 Not tainted 5.14.0-syzkaller #0 [ 55.161732][ T7302] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.172003][ T7302] Call Trace: [ 55.175286][ T7302] dump_stack_lvl+0x1dc/0x2d8 [ 55.180056][ T7302] ? show_regs_print_info+0x12/0x12 [ 55.185331][ T7302] ? save_trace+0x5a/0x9f0 [ 55.189834][ T7302] ? print_circular_bug+0x48e/0x5d0 [ 55.195223][ T7302] check_noncircular+0x2f9/0x3b0 [ 55.200391][ T7302] ? add_chain_block+0x850/0x850 [ 55.205324][ T7302] ? lockdep_lock+0x11d/0x2e0 [ 55.210002][ T7302] validate_chain+0x1dfb/0x8240 [ 55.215402][ T7302] ? reacquire_held_locks+0x620/0x620 [ 55.221045][ T7302] ? mark_lock+0x191/0x1e00 [ 55.229546][ T7302] ? __print_lock_name+0x1d0/0x1d0 [ 55.234816][ T7302] ? mark_lock+0x191/0x1e00 [ 55.239393][ T7302] ? rcu_read_lock_sched_held+0x89/0x130 [ 55.245226][ T7302] ? __bpf_trace_rcu_stall_warning+0x10/0x10 [ 55.251379][ T7302] __lock_acquire+0x1382/0x2b00 [ 55.256311][ T7302] ? trace_lock_acquire+0x190/0x190 [ 55.261674][ T7302] ? _raw_spin_unlock_irqrestore+0x8b/0x130 [ 55.267659][ T7302] ? lockdep_hardirqs_on+0x95/0x140 [ 55.273217][ T7302] lock_acquire+0x19f/0x4d0 [ 55.277907][ T7302] ? io_sq_thread+0x92c/0x12a0 [ 55.282760][ T7302] ? read_lock_is_recursive+0x10/0x10 [ 55.288143][ T7302] ? __might_sleep+0x110/0x110 [ 55.292984][ T7302] ? rcu_lock_release+0x20/0x20 [ 55.298221][ T7302] __mutex_lock_common+0x1df/0x2550 [ 55.304390][ T7302] ? io_sq_thread+0x92c/0x12a0 [ 55.309523][ T7302] ? io_sq_thread+0x92c/0x12a0 [ 55.314305][ T7302] ? mutex_lock_io_nested+0x60/0x60 [ 55.319501][ T7302] ? set_cpus_allowed_ptr+0x94/0xd0 [ 55.324994][ T7302] ? release_user_cpus_ptr+0x60/0x60 [ 55.330286][ T7302] mutex_lock_nested+0x1a/0x20 [ 55.335089][ T7302] io_sq_thread+0x92c/0x12a0 [ 55.339681][ T7302] ? io_fallback_req_func+0x270/0x270 [ 55.345037][ T7302] ? lockdep_hardirqs_on_prepare+0x412/0x780 executing program executing program [ 55.351002][ T7302] ? init_wait_entry+0xd0/0xd0 [ 55.355924][ T7302] ? _raw_spin_unlock_irq+0x1f/0x40 [ 55.361188][ T7302] ? lockdep_hardirqs_on+0x95/0x140 [ 55.366370][ T7302] ? io_fallback_req_func+0x270/0x270 [ 55.371920][ T7302] ret_from_fork+0x1f/0x30 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program