INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.18' (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 syzkaller login: [ 438.823047] INFO: rcu_sched self-detected stall on CPU [ 438.828540] 0-....: (124999 ticks this GP) idle=6ea/1/4611686018427387906 softirq=9748/9748 fqs=31240 [ 438.838097] (t=125000 jiffies g=4823 c=4822 q=10) [ 438.843089] NMI backtrace for cpu 0 [ 438.846688] CPU: 0 PID: 4469 Comm: syzkaller058368 Not tainted 4.16.0-rc7+ #5 [ 438.853928] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 438.863297] Call Trace: [ 438.865853] [ 438.868078] dump_stack+0x194/0x24d [ 438.871686] ? arch_local_irq_restore+0x53/0x53 [ 438.876372] ? lock_release+0xa40/0xa40 [ 438.880324] ? nmi_cpu_backtrace+0x1be/0x210 [ 438.884759] ? lapic_can_unplug_cpu+0xa0/0xa0 [ 438.889234] nmi_cpu_backtrace+0x1d2/0x210 [ 438.893448] ? lapic_can_unplug_cpu+0xa0/0xa0 [ 438.897919] nmi_trigger_cpumask_backtrace+0x123/0x180 [ 438.903173] arch_trigger_cpumask_backtrace+0x14/0x20 [ 438.908377] rcu_dump_cpu_stacks+0x186/0x1de [ 438.912784] check_cpu_stall.isra.61+0xbb8/0x15b0 [ 438.917610] ? rcu_lockdep_current_cpu_online+0x190/0x190 [ 438.923130] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 438.928305] ? __lock_acquire+0x664/0x3e00 [ 438.932547] ? find_held_lock+0x35/0x1d0 [ 438.936607] ? notifier_call_chain+0x136/0x2c0 [ 438.941162] ? lock_downgrade+0x980/0x980 [ 438.945287] ? trace_hardirqs_off+0x10/0x10 [ 438.949577] ? lock_release+0xa40/0xa40 [ 438.953539] ? trace_hardirqs_off+0x10/0x10 [ 438.957834] ? find_held_lock+0x35/0x1d0 [ 438.961874] ? trace_hardirqs_off+0x10/0x10 [ 438.966166] ? cpuacct_account_field+0x1e4/0x3b0 [ 438.970908] ? find_held_lock+0x35/0x1d0 [ 438.974945] ? trace_hardirqs_off+0x10/0x10 [ 438.979247] ? __lock_is_held+0xb6/0x140 [ 438.983322] rcu_check_callbacks+0x238/0xd20 [ 438.987713] ? rcu_cpu_stall_reset+0x260/0x260 [ 438.992271] ? trace_hardirqs_off+0xd/0x10 [ 438.996495] ? raise_softirq+0x325/0x490 [ 439.000537] ? raise_softirq_irqoff+0x320/0x320 [ 439.005218] ? read_boot_clock64+0x70/0x70 [ 439.009439] ? lock_downgrade+0x980/0x980 [ 439.013559] ? hrtimer_run_queues+0x5e/0x380 [ 439.017945] ? run_local_timers+0x14c/0x1b0 [ 439.022435] ? timer_clear_idle+0x50/0x50 [ 439.026593] ? account_process_tick+0xd4/0x3e0 [ 439.031150] ? thread_group_cputime+0xef0/0xef0 [ 439.035795] ? get_monotonic_coarse64+0x470/0x470 [ 439.040621] update_process_times+0x30/0x60 [ 439.044954] tick_sched_handle+0x85/0x160 [ 439.049080] tick_sched_timer+0x42/0x120 [ 439.053127] __hrtimer_run_queues+0x39c/0xec0 [ 439.057601] ? tick_sched_do_timer+0xe0/0xe0 [ 439.061988] ? hrtimer_fixup_init+0x70/0x70 [ 439.066328] ? pvclock_read_flags+0x160/0x160 [ 439.070803] ? lock_acquire+0x1d5/0x580 [ 439.074750] ? ktime_get+0x26f/0x3a0 [ 439.078441] ? kvm_clock_get_cycles+0x25/0x30 [ 439.082913] ? ktime_get_update_offsets_now+0x34a/0x520 [ 439.088266] ? do_timer+0x50/0x50 [ 439.091707] ? native_apic_msr_write+0x5c/0x80 [ 439.096273] ? rcu_idle_enter+0x530/0x530 [ 439.100395] ? lapic_next_event+0x54/0x80 [ 439.104519] ? clockevents_program_event+0x108/0x2e0 [ 439.109602] hrtimer_interrupt+0x2a5/0x6f0 [ 439.113873] smp_apic_timer_interrupt+0x14a/0x700 [ 439.118694] ? smp_call_function_single_interrupt+0x640/0x640 [ 439.124553] ? _raw_spin_lock+0x32/0x40 [ 439.128510] ? _raw_spin_unlock+0x22/0x30 [ 439.132643] ? handle_edge_irq+0x2b4/0x7c0 [ 439.136855] ? task_prio+0x50/0x50 [ 439.140416] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 439.145240] apic_timer_interrupt+0xf/0x20 [ 439.149446] [ 439.151704] RIP: 0010:__process_echoes+0x5d9/0x770 [ 439.156603] RSP: 0018:ffff8801af12f7f0 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff12 [ 439.164285] RAX: 0000000000000594 RBX: ffffc90001946000 RCX: ffffffff82f38469 [ 439.171527] RDX: 0000000000000000 RSI: 1ffff1003543c565 RDI: ffffc900019477f4 [ 439.178769] RBP: ffff8801af12f858 R08: 1ffff10035e25ea4 R09: 0000000000000000 [ 439.186020] R10: 0000000000000000 R11: 0000000000000000 R12: 00000005e6b39594 [ 439.193274] R13: dffffc0000000000 R14: 00000005e6b39594 R15: 0000000000003803 [ 439.200552] ? __process_echoes+0x5c9/0x770 [ 439.204870] n_tty_receive_buf_common+0x1380/0x2520 [ 439.209882] ? n_tty_receive_char_special+0x2c90/0x2c90 [ 439.215223] ? rcu_note_context_switch+0x710/0x710 [ 439.220138] n_tty_receive_buf+0x30/0x40 [ 439.224232] tty_ioctl+0x9c5/0x1610 [ 439.227839] ? tty_vhangup+0x30/0x30 [ 439.231532] ? __lock_is_held+0xb6/0x140 [ 439.235606] ? __fget+0x36b/0x5b0 [ 439.239079] ? handle_mm_fault+0x35b/0xb10 [ 439.243298] ? iterate_fd+0x3f0/0x3f0 [ 439.247078] ? __do_page_fault+0x5f7/0xc90 [ 439.251287] ? lock_downgrade+0x980/0x980 [ 439.255411] ? tty_vhangup+0x30/0x30 [ 439.259097] do_vfs_ioctl+0x1b1/0x1520 [ 439.262960] ? handle_mm_fault+0x465/0xb10 [ 439.267170] ? check_same_owner+0x320/0x320 [ 439.271474] ? ioctl_preallocate+0x2b0/0x2b0 [ 439.275867] ? fget_raw+0x20/0x20 [ 439.279300] ? up_read+0x1a/0x40 [ 439.282648] ? __do_page_fault+0x3d6/0xc90 [ 439.286872] ? mm_fault_error+0x2c0/0x2c0 [ 439.291069] ? security_file_ioctl+0x89/0xb0 [ 439.295461] SyS_ioctl+0x8f/0xc0 [ 439.298805] ? do_vfs_ioctl+0x1520/0x1520 [ 439.302936] do_syscall_64+0x281/0x940 [ 439.306794] ? __do_page_fault+0xc90/0xc90 [ 439.311020] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 439.316547] ? syscall_return_slowpath+0x550/0x550 [ 439.321453] ? syscall_return_slowpath+0x2ac/0x550 [ 439.326361] ? retint_user+0x18/0x18 [ 439.330061] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 439.334893] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 439.340056] RIP: 0033:0x446979 [ 439.343221] RSP: 002b:00007fb18094bd18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 439.350904] RAX: ffffffffffffffda RBX: 00000000006e29fc RCX: 0000000000446979 [ 439.358152] RDX: 00000000200000c0 RSI: 0000000000005412 RDI: 0000000000000004 [ 439.365404] RBP: 00000000006e29f8 R08: 0000000000000000 R09: 0000000000000000 [ 439.372648] R10: 0000000000000000 R11: 0000000000000246 R12: 6d74702f7665642f [ 439.379893] R13: 00007ffc95813d0f R14: 00007fb18094c9c0 R15: 0000000000000001