[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.669137][ T26] audit: type=1800 audit(1554309864.301:25): pid=7739 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 38.698187][ T26] audit: type=1800 audit(1554309864.301:26): pid=7739 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 38.724990][ T26] audit: type=1800 audit(1554309864.301:27): pid=7739 uid=0 auid=4294967295 ses=4294967295 subj==unconfined 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 '10.128.15.193' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 546.464489][ T1042] INFO: task syz-executor912:7890 blocked for more than 143 seconds. [ 546.473032][ T1042] Not tainted 5.1.0-rc3+ #48 [ 546.478319][ T1042] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 546.487298][ T1042] syz-executor912 D28216 7890 7888 0xa0020000 [ 546.493800][ T1042] Call Trace: [ 546.497284][ T1042] __schedule+0x817/0x1cc0 [ 546.501742][ T1042] ? __sched_text_start+0x8/0x8 [ 546.507060][ T1042] ? __lock_acquire+0x242a/0x3fb0 [ 546.512374][ T1042] schedule+0x92/0x180 [ 546.516627][ T1042] schedule_timeout+0x8ca/0xfd0 [ 546.521753][ T1042] ? wait_for_completion+0x294/0x440 [ 546.527361][ T1042] ? find_held_lock+0x35/0x130 [ 546.533264][ T1042] ? usleep_range+0x170/0x170 [ 546.538225][ T1042] ? kasan_check_write+0x14/0x20 [ 546.543546][ T1042] ? _raw_spin_unlock_irq+0x28/0x90 [ 546.548845][ T1042] ? wait_for_completion+0x294/0x440 [ 546.554226][ T1042] ? _raw_spin_unlock_irq+0x28/0x90 [ 546.559839][ T1042] ? lockdep_hardirqs_on+0x418/0x5d0 [ 546.566037][ T1042] ? trace_hardirqs_on+0x67/0x230 [ 546.571120][ T1042] ? kasan_check_read+0x11/0x20 [ 546.576133][ T1042] wait_for_completion+0x29c/0x440 [ 546.581252][ T1042] ? lockdep_hardirqs_on+0x418/0x5d0 [ 546.586856][ T1042] ? wait_for_completion_interruptible+0x4b0/0x4b0 [ 546.593440][ T1042] ? wake_up_q+0xf0/0xf0 [ 546.597815][ T1042] ? percpu_ref_kill_and_confirm+0x1b7/0x3b0 [ 546.604041][ T1042] exit_aio+0x321/0x3a0 [ 546.608404][ T1042] ? aio_poll_wake+0x11e0/0x11e0 [ 546.613357][ T1042] ? mutex_unlock+0xd/0x10 [ 546.618045][ T1042] mmput+0xcf/0x4c0 [ 546.621896][ T1042] do_exit+0x816/0x2fa0 [ 546.626302][ T1042] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 546.632873][ T1042] ? __check_heap_object+0x81/0xb3 [ 546.638344][ T1042] ? mm_update_next_owner+0x640/0x640 [ 546.643831][ T1042] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 546.650174][ T1042] ? __ia32_compat_sys_io_submit+0x356/0x570 [ 546.656217][ T1042] ? __ia32_sys_io_submit+0x560/0x560 [ 546.661908][ T1042] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 546.667603][ T1042] do_group_exit+0x135/0x370 [ 546.672314][ T1042] __ia32_sys_exit_group+0x44/0x50 [ 546.677520][ T1042] do_fast_syscall_32+0x281/0xc98 [ 546.682567][ T1042] entry_SYSENTER_compat+0x70/0x7f [ 546.687752][ T1042] RIP: 0023:0xf7f04869 [ 546.692021][ T1042] Code: Bad RIP value. [ 546.696185][ T1042] RSP: 002b:00000000ffff586c EFLAGS: 00000296 ORIG_RAX: 00000000000000fc [ 546.704990][ T1042] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000080eb2b8 [ 546.713578][ T1042] RDX: 0000000000000000 RSI: 00000000080d5ed8 RDI: 00000000080eb2c0 [ 546.721748][ T1042] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 [ 546.730040][ T1042] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 546.738488][ T1042] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 546.746732][ T1042] [ 546.746732][ T1042] Showing all locks held in the system: [ 546.754662][ T1042] 1 lock held by khungtaskd/1042: [ 546.759739][ T1042] #0: 000000008fe3d45c (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e [ 546.769296][ T1042] 1 lock held by rsyslogd/7777: [ 546.774148][ T1042] #0: 00000000d0b95c74 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 [ 546.783072][ T1042] 2 locks held by getty/7868: [ 546.787772][ T1042] #0: 0000000074c06bff (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.796774][ T1042] #1: 00000000c51cecb7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.806461][ T1042] 2 locks held by getty/7869: [ 546.811122][ T1042] #0: 00000000595d0e16 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.820198][ T1042] #1: 00000000b494bab1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.829821][ T1042] 2 locks held by getty/7870: [ 546.834583][ T1042] #0: 00000000fbf4cf72 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.843565][ T1042] #1: 0000000049a5ec7e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.853268][ T1042] 2 locks held by getty/7871: [ 546.857998][ T1042] #0: 00000000455ebfb5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.867012][ T1042] #1: 0000000085a327f6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.876633][ T1042] 2 locks held by getty/7872: [ 546.881471][ T1042] #0: 00000000b83e1736 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.890533][ T1042] #1: 000000006f859b6a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.900179][ T1042] 2 locks held by getty/7873: [ 546.905234][ T1042] #0: 0000000034572fb1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.914302][ T1042] #1: 00000000a2dc1d96 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.923951][ T1042] 2 locks held by getty/7874: [ 546.928726][ T1042] #0: 00000000929d94fb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.937719][ T1042] #1: 0000000040f0644a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.947371][ T1042] [ 546.949762][ T1042] ============================================= [ 546.949762][ T1042] [ 546.958236][ T1042] NMI backtrace for cpu 1 [ 546.962572][ T1042] CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc3+ #48 [ 546.970183][ T1042] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 546.980223][ T1042] Call Trace: [ 546.983616][ T1042] dump_stack+0x172/0x1f0 [ 546.987946][ T1042] nmi_cpu_backtrace.cold+0x63/0xa4 [ 546.993173][ T1042] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 546.998799][ T1042] nmi_trigger_cpumask_backtrace+0x1be/0x236 [ 547.004770][ T1042] arch_trigger_cpumask_backtrace+0x14/0x20 [ 547.010658][ T1042] watchdog+0x9b7/0xec0 [ 547.014858][ T1042] kthread+0x357/0x430 [ 547.018915][ T1042] ? reset_hung_task_detector+0x30/0x30 [ 547.024505][ T1042] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 547.030834][ T1042] ret_from_fork+0x3a/0x50 [ 547.035399][ T1042] Sending NMI from CPU 1 to CPUs 0: [ 547.040688][ C0] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x2/0x10 [ 547.041612][ T1042] Kernel panic - not syncing: hung_task: blocked tasks [ 547.055775][ T1042] CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc3+ #48 [ 547.063330][ T1042] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 547.073511][ T1042] Call Trace: [ 547.076790][ T1042] dump_stack+0x172/0x1f0 [ 547.081113][ T1042] panic+0x2cb/0x65c [ 547.084998][ T1042] ? __warn_printk+0xf3/0xf3 [ 547.089630][ T1042] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 547.095406][ T1042] ? printk_safe_flush+0xf2/0x140 [ 547.100471][ T1042] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 547.106789][ T1042] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 547.112458][ T1042] ? nmi_trigger_cpumask_backtrace+0x1a7/0x236 [ 547.118895][ T1042] ? nmi_trigger_cpumask_backtrace+0x19e/0x236 [ 547.125368][ T1042] watchdog+0x9c8/0xec0 [ 547.129659][ T1042] kthread+0x357/0x430 [ 547.139805][ T1042] ? reset_hung_task_detector+0x30/0x30 [ 547.145430][ T1042] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 547.151661][ T1042] ret_from_fork+0x3a/0x50 [ 547.157047][ T1042] Kernel Offset: disabled [ 547.161383][ T1042] Rebooting in 86400 seconds..