[ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.208' (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 syzkaller login: [ 721.364702][ T1653] INFO: task iou-sqp-8700:8701 blocked for more than 143 seconds. [ 721.374724][ T1653] Not tainted 5.12.0-rc7-next-20210415-syzkaller #0 [ 721.381851][ T1653] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 721.395943][ T1653] task:iou-sqp-8700 state:D stack:28960 pid: 8701 ppid: 8414 flags:0x00004004 [ 721.407524][ T1653] Call Trace: [ 721.411046][ T1653] __schedule+0x917/0x2170 [ 721.418240][ T1653] ? io_schedule_timeout+0x140/0x140 [ 721.423715][ T1653] ? prepare_to_wait+0x122/0x3f0 [ 721.428938][ T1653] ? io_uring_try_cancel_requests+0xbd0/0xbd0 [ 721.436439][ T1653] schedule+0xcf/0x270 [ 721.440866][ T1653] __io_uring_cancel+0x285/0x420 [ 721.446065][ T1653] ? __io_uring_free+0x110/0x110 [ 721.451342][ T1653] ? finish_wait+0x260/0x260 [ 721.456221][ T1653] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 721.463798][ T1653] ? __validate_process_creds+0x20c/0x370 [ 721.469793][ T1653] do_exit+0x299/0x2a70 [ 721.474174][ T1653] ? find_held_lock+0x2d/0x110 [ 721.479505][ T1653] ? mm_update_next_owner+0x7a0/0x7a0 [ 721.485097][ T1653] ? lock_downgrade+0x6e0/0x6e0 [ 721.491234][ T1653] ? _raw_spin_unlock_irqrestore+0x50/0x70 [ 721.497309][ T1653] io_sq_thread+0x60a/0x1340 [ 721.502117][ T1653] ? io_submit_sqes+0x6c40/0x6c40 [ 721.507580][ T1653] ? finish_wait+0x260/0x260 [ 721.513883][ T1653] ? find_held_lock+0x2d/0x110 [ 721.520077][ T1653] ? ret_from_fork+0x8/0x30 [ 721.525142][ T1653] ? lock_downgrade+0x6e0/0x6e0 [ 721.530881][ T1653] ? do_raw_spin_lock+0x120/0x2b0 [ 721.537595][ T1653] ? rwlock_bug.part.0+0x90/0x90 [ 721.543514][ T1653] ? _raw_spin_unlock_irq+0x1f/0x40 [ 721.548955][ T1653] ? io_submit_sqes+0x6c40/0x6c40 [ 721.554597][ T1653] ret_from_fork+0x1f/0x30 [ 721.559491][ T1653] [ 721.559491][ T1653] Showing all locks held in the system: [ 721.568177][ T1653] 1 lock held by khungtaskd/1653: [ 721.573404][ T1653] #0: ffffffff8bf76560 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 [ 721.584257][ T1653] 1 lock held by in:imklog/8133: [ 721.589349][ T1653] #0: ffff888013088370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 [ 721.598910][ T1653] [ 721.601257][ T1653] ============================================= [ 721.601257][ T1653] [ 721.610442][ T1653] NMI backtrace for cpu 1 [ 721.615030][ T1653] CPU: 1 PID: 1653 Comm: khungtaskd Not tainted 5.12.0-rc7-next-20210415-syzkaller #0 [ 721.624986][ T1653] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 721.635950][ T1653] Call Trace: [ 721.641617][ T1653] dump_stack+0x141/0x1d7 [ 721.646231][ T1653] nmi_cpu_backtrace.cold+0x44/0xd7 [ 721.651492][ T1653] ? lapic_can_unplug_cpu+0x80/0x80 [ 721.657533][ T1653] nmi_trigger_cpumask_backtrace+0x1b3/0x230 [ 721.663947][ T1653] watchdog+0xd3b/0xf50 [ 721.668190][ T1653] ? trace_sched_process_hang+0x280/0x280 [ 721.674295][ T1653] kthread+0x3b1/0x4a0 [ 721.678556][ T1653] ? __kthread_bind_mask+0xc0/0xc0 [ 721.683821][ T1653] ret_from_fork+0x1f/0x30 [ 721.688538][ T1653] Sending NMI from CPU 1 to CPUs 0: [ 721.694819][ C0] NMI backtrace for cpu 0 [ 721.694834][ C0] CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.12.0-rc7-next-20210415-syzkaller #0 [ 721.694845][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 721.694855][ C0] Workqueue: events toggle_allocation_gate [ 721.694869][ C0] RIP: 0010:preempt_count_sub+0x56/0x150 [ 721.694880][ C0] Code: 85 e4 00 00 00 8b 0d 19 08 e5 0e 85 c9 75 1b 65 8b 05 ae 60 b3 7e 89 c2 81 e2 ff ff ff 7f 39 da 7c 13 81 fb fe 00 00 00 76 63 db 65 01 1d 91 60 b3 7e 5b c3 e8 4a cd c2 07 85 c0 74 f5 48 c7 [ 721.694896][ C0] RSP: 0018:ffffc90000cc79f8 EFLAGS: 00000002 [ 721.694908][ C0] RAX: 0000000080000002 RBX: 0000000000000001 RCX: 0000000000000000 [ 721.694918][ C0] RDX: 0000000000000002 RSI: ffffffff83e7543f RDI: 0000000000000001 [ 721.694927][ C0] RBP: ffff8880b9c34a80 R08: 0000000000000002 R09: 000000000000eb19 [ 721.694936][ C0] R10: ffffffff83e7538c R11: 000000000000003f R12: 0000000000000008 [ 721.694945][ C0] R13: ffff888140120660 R14: 0000000000000000 R15: 0000000000000000 [ 721.694954][ C0] FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 [ 721.694964][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 721.694972][ C0] CR2: 00007ffa2b511018 CR3: 000000000bc8e000 CR4: 00000000001506f0 [ 721.694981][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 721.694990][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 721.694998][ C0] Call Trace: [ 721.695003][ C0] flush_tlb_mm_range+0x111/0x230 [ 721.695010][ C0] ? __kmalloc_node_track_caller+0xcf/0x350 [ 721.695017][ C0] __text_poke+0x590/0x8c0 [ 721.695023][ C0] ? text_poke_loc_init+0x340/0x340 [ 721.695031][ C0] ? __kmalloc_node_track_caller+0xcf/0x350 [ 721.695038][ C0] text_poke_bp_batch+0x3d7/0x560 [ 721.695045][ C0] ? alternatives_enable_smp+0xf0/0xf0 [ 721.695053][ C0] ? mutex_lock_io_nested+0xf70/0xf70 [ 721.695060][ C0] ? arch_jump_label_transform_queue+0x9d/0xf0 [ 721.695068][ C0] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 721.695076][ C0] ? __jump_label_update+0x351/0x400 [ 721.695083][ C0] text_poke_finish+0x16/0x30 [ 721.695090][ C0] arch_jump_label_transform_apply+0x13/0x20 [ 721.695097][ C0] jump_label_update+0x1da/0x400 [ 721.695104][ C0] static_key_enable_cpuslocked+0x1b1/0x260 [ 721.695112][ C0] static_key_enable+0x16/0x20 [ 721.695119][ C0] toggle_allocation_gate+0xbf/0x2e0 [ 721.695126][ C0] ? param_get_sample_interval+0x70/0x70 [ 721.695133][ C0] process_one_work+0x98d/0x1600 [ 721.695141][ C0] ? pwq_dec_nr_in_flight+0x320/0x320 [ 721.695148][ C0] ? rwlock_bug.part.0+0x90/0x90 [ 721.695155][ C0] ? _raw_spin_lock_irq+0x41/0x50 [ 721.695162][ C0] worker_thread+0x64c/0x1120 [ 721.695168][ C0] ? process_one_work+0x1600/0x1600 [ 721.695175][ C0] kthread+0x3b1/0x4a0 [ 721.695181][ C0] ? __kthread_bind_mask+0xc0/0xc0 [ 721.695188][ C0] ret_from_fork+0x1f/0x30 [ 721.714474][ T1653] Kernel panic - not syncing: hung_task: blocked tasks [ 722.002527][ T1653] CPU: 1 PID: 1653 Comm: khungtaskd Not tainted 5.12.0-rc7-next-20210415-syzkaller #0 [ 722.012540][ T1653] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 722.023545][ T1653] Call Trace: [ 722.026863][ T1653] dump_stack+0x141/0x1d7 [ 722.031361][ T1653] panic+0x306/0x73d [ 722.036619][ T1653] ? __warn_printk+0xf3/0xf3 [ 722.041905][ T1653] ? lapic_can_unplug_cpu+0x80/0x80 [ 722.049152][ T1653] ? preempt_schedule_thunk+0x16/0x18 [ 722.056316][ T1653] ? nmi_trigger_cpumask_backtrace+0x196/0x230 [ 722.062646][ T1653] ? watchdog.cold+0x22d/0x248 [ 722.067846][ T1653] watchdog.cold+0x23e/0x248 [ 722.072502][ T1653] ? trace_sched_process_hang+0x280/0x280 [ 722.078562][ T1653] kthread+0x3b1/0x4a0 [ 722.082887][ T1653] ? __kthread_bind_mask+0xc0/0xc0 [ 722.088310][ T1653] ret_from_fork+0x1f/0x30 [ 722.093737][ T1653] Kernel Offset: disabled [ 722.098270][ T1653] Rebooting in 86400 seconds..