[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.726593][ T26] audit: type=1800 audit(1554584149.899:25): pid=7787 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 39.762698][ T26] audit: type=1800 audit(1554584149.909:26): pid=7787 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 39.791856][ T26] audit: type=1800 audit(1554584149.909:27): pid=7787 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] 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 '10.128.0.179' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 507.448185][ T1042] INFO: task syz-executor722:7940 blocked for more than 143 seconds. [ 507.456517][ T1042] Not tainted 5.1.0-rc3+ #55 [ 507.462186][ T1042] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 507.471034][ T1042] syz-executor722 D28216 7940 7938 0x80000000 [ 507.477371][ T1042] Call Trace: [ 507.480768][ T1042] __schedule+0x817/0x1cc0 [ 507.485215][ T1042] ? __sched_text_start+0x8/0x8 [ 507.490149][ T1042] ? __lock_acquire+0x242a/0x3fb0 [ 507.495174][ T1042] schedule+0x92/0x180 [ 507.499310][ T1042] schedule_timeout+0x8ca/0xfd0 [ 507.504160][ T1042] ? wait_for_completion+0x294/0x440 [ 507.509493][ T1042] ? find_held_lock+0x35/0x130 [ 507.514240][ T1042] ? usleep_range+0x170/0x170 [ 507.519015][ T1042] ? kasan_check_write+0x14/0x20 [ 507.524002][ T1042] ? _raw_spin_unlock_irq+0x28/0x90 [ 507.529230][ T1042] ? wait_for_completion+0x294/0x440 [ 507.534500][ T1042] ? _raw_spin_unlock_irq+0x28/0x90 [ 507.539726][ T1042] ? lockdep_hardirqs_on+0x418/0x5d0 [ 507.545047][ T1042] ? trace_hardirqs_on+0x67/0x230 [ 507.550114][ T1042] ? kasan_check_read+0x11/0x20 [ 507.555020][ T1042] wait_for_completion+0x29c/0x440 [ 507.560174][ T1042] ? lockdep_hardirqs_on+0x418/0x5d0 [ 507.565461][ T1042] ? wait_for_completion_interruptible+0x4b0/0x4b0 [ 507.572053][ T1042] ? wake_up_q+0xf0/0xf0 [ 507.576333][ T1042] ? percpu_ref_kill_and_confirm+0x1b7/0x3b0 [ 507.582476][ T1042] exit_aio+0x321/0x3a0 [ 507.586636][ T1042] ? aio_poll_wake+0x11e0/0x11e0 [ 507.591649][ T1042] ? mutex_unlock+0xd/0x10 [ 507.596090][ T1042] mmput+0xcf/0x4c0 [ 507.600002][ T1042] do_exit+0x816/0x2fa0 [ 507.604193][ T1042] ? lock_downgrade+0x880/0x880 [ 507.609112][ T1042] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 507.615356][ T1042] ? kasan_check_read+0x11/0x20 [ 507.620256][ T1042] ? mm_update_next_owner+0x640/0x640 [ 507.625617][ T1042] ? __x64_sys_io_submit+0x37d/0x580 [ 507.630944][ T1042] ? __ia32_sys_io_destroy+0x420/0x420 [ 507.636447][ T1042] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 507.642081][ T1042] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 507.647591][ T1042] do_group_exit+0x135/0x370 [ 507.652247][ T1042] __x64_sys_exit_group+0x44/0x50 [ 507.657358][ T1042] do_syscall_64+0x103/0x610 [ 507.661993][ T1042] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 507.667915][ T1042] RIP: 0033:0x43ee98 [ 507.671810][ T1042] Code: Bad RIP value. [ 507.675856][ T1042] RSP: 002b:00007ffe89287a18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 507.684320][ T1042] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ee98 [ 507.692313][ T1042] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 507.700327][ T1042] RBP: 00000000004be6a8 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 507.708375][ T1042] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 507.716354][ T1042] R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000 [ 507.724379][ T1042] [ 507.724379][ T1042] Showing all locks held in the system: [ 507.732163][ T1042] 1 lock held by khungtaskd/1042: [ 507.737179][ T1042] #0: 0000000026e49591 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e [ 507.746611][ T1042] 1 lock held by rsyslogd/7825: [ 507.751498][ T1042] #0: 000000003af41dc6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 [ 507.760228][ T1042] 2 locks held by getty/7915: [ 507.764910][ T1042] #0: 00000000980fbe8c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 507.774017][ T1042] #1: 00000000dcbd507d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 507.783657][ T1042] 2 locks held by getty/7916: [ 507.788388][ T1042] #0: 00000000f6c9aacb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 507.797344][ T1042] #1: 000000006641d4c9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 507.807037][ T1042] 2 locks held by getty/7917: [ 507.811795][ T1042] #0: 0000000064f720df (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 507.820866][ T1042] #1: 0000000059c4fb7f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 507.830469][ T1042] 2 locks held by getty/7918: [ 507.835120][ T1042] #0: 000000001347d4ad (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 507.844107][ T1042] #1: 0000000008583462 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 507.853693][ T1042] 2 locks held by getty/7919: [ 507.858396][ T1042] #0: 0000000085cd28d8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 507.867327][ T1042] #1: 0000000089c34d0e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 507.877025][ T1042] 2 locks held by getty/7920: [ 507.881736][ T1042] #0: 0000000052f586a5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 507.890736][ T1042] #1: 00000000b7fa2452 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 507.900343][ T1042] 2 locks held by getty/7921: [ 507.905001][ T1042] #0: 000000006530f2ac (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 507.913970][ T1042] #1: 000000006d1b7f6d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 507.923827][ T1042] [ 507.926151][ T1042] ============================================= [ 507.926151][ T1042] [ 507.934655][ T1042] NMI backtrace for cpu 0 [ 507.939051][ T1042] CPU: 0 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc3+ #55 [ 507.946572][ T1042] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 507.956600][ T1042] Call Trace: [ 507.959945][ T1042] dump_stack+0x172/0x1f0 [ 507.964283][ T1042] nmi_cpu_backtrace.cold+0x63/0xa4 [ 507.969502][ T1042] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 507.975152][ T1042] nmi_trigger_cpumask_backtrace+0x1be/0x236 [ 507.981153][ T1042] arch_trigger_cpumask_backtrace+0x14/0x20 [ 507.987035][ T1042] watchdog+0x9b7/0xec0 [ 507.991208][ T1042] kthread+0x357/0x430 [ 507.995271][ T1042] ? reset_hung_task_detector+0x30/0x30 [ 508.000821][ T1042] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 508.007042][ T1042] ret_from_fork+0x3a/0x50 [ 508.011561][ T1042] Sending NMI from CPU 0 to CPUs 1: [ 508.016830][ C1] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x2/0x10 [ 508.017771][ T1042] Kernel panic - not syncing: hung_task: blocked tasks [ 508.031963][ T1042] CPU: 0 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc3+ #55 [ 508.039479][ T1042] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 508.049586][ T1042] Call Trace: [ 508.052872][ T1042] dump_stack+0x172/0x1f0 [ 508.057188][ T1042] panic+0x2cb/0x65c [ 508.061066][ T1042] ? __warn_printk+0xf3/0xf3 [ 508.065717][ T1042] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 508.071483][ T1042] ? printk_safe_flush+0xf2/0x140 [ 508.076495][ T1042] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 508.082824][ T1042] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 508.088463][ T1042] ? nmi_trigger_cpumask_backtrace+0x1a7/0x236 [ 508.094591][ T1042] ? nmi_trigger_cpumask_backtrace+0x19e/0x236 [ 508.100722][ T1042] watchdog+0x9c8/0xec0 [ 508.104859][ T1042] kthread+0x357/0x430 [ 508.108906][ T1042] ? reset_hung_task_detector+0x30/0x30 [ 508.114425][ T1042] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 508.120640][ T1042] ret_from_fork+0x3a/0x50 [ 508.125912][ T1042] Kernel Offset: disabled [ 508.130241][ T1042] Rebooting in 86400 seconds..