[  OK  ] Reached target Graphical Interface.
         Starting Update UTMP about System Runlevel Changes...
         Starting Load/Save RF Kill Switch Status...
[  OK  ] Started Load/Save RF Kill Switch Status.
[  OK  ] Started Update UTMP about System Runlevel Changes.

Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.1.88' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [  753.096428] EXT4-fs (loop0): feature flags set on rev 0 fs, running e2fsck is recommended
[  753.115360] EXT4-fs (loop0): can't mount with journal_checksum, fs mounted w/o journal
[ 1001.351495] INFO: task syz-executor465:7959 blocked for more than 140 seconds.
[ 1001.358916]       Not tainted 4.14.243-syzkaller #0
[ 1001.364925] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1001.372926] syz-executor465 D28584  7959   7958 0x00000004
[ 1001.378533] Call Trace:
[ 1001.381099]  __schedule+0x88b/0x1de0
[ 1001.384841]  ? io_schedule_timeout+0x140/0x140
[ 1001.389412]  ? trace_hardirqs_on+0x10/0x10
[ 1001.393670]  schedule+0x8d/0x1b0
[ 1001.397023]  schedule_timeout+0x80a/0xe90
[ 1001.401147]  ? debug_object_assert_init+0x22d/0x2d0
[ 1001.406176]  ? usleep_range+0x130/0x130
[ 1001.410134]  ? wait_for_common+0x26a/0x430
[ 1001.414396]  ? mark_held_locks+0xa6/0xf0
[ 1001.418438]  ? _raw_spin_unlock_irq+0x24/0x80
[ 1001.423496]  wait_for_common+0x272/0x430
[ 1001.427546]  ? try_to_wake_up+0x706/0x1100
[ 1001.431805]  ? out_of_line_wait_on_atomic_t+0x1a0/0x1a0
[ 1001.437151]  ? trace_hardirqs_on_caller+0x3a8/0x580
[ 1001.442225]  ? wake_up_q+0xd0/0xd0
[ 1001.445794]  ? rcu_lockdep_current_cpu_online+0xed/0x140
[ 1001.451223]  kthread_stop+0xce/0x640
[ 1001.454964]  ext4_fill_super+0x6880/0xb290
[ 1001.459205]  ? ext4_calculate_overhead+0x1020/0x1020
[ 1001.464323]  ? lock_downgrade+0x740/0x740
[ 1001.468456]  ? snprintf+0xa5/0xd0
[ 1001.471932]  ? ns_test_super+0x50/0x50
[ 1001.475801]  ? set_blocksize+0x125/0x380
[ 1001.479839]  mount_bdev+0x2b3/0x360
[ 1001.483483]  ? ext4_calculate_overhead+0x1020/0x1020
[ 1001.491101]  mount_fs+0x92/0x2a0
[ 1001.494495]  vfs_kern_mount.part.0+0x5b/0x470
[ 1001.498974]  do_mount+0xe53/0x2a00
[ 1001.502537]  ? retint_kernel+0x2d/0x2d
[ 1001.506409]  ? copy_mount_string+0x40/0x40
[ 1001.510621]  ? memset+0x20/0x40
[ 1001.513924]  ? copy_mount_options+0x1fa/0x2f0
[ 1001.518401]  ? copy_mnt_ns+0xa30/0xa30
[ 1001.522348]  SyS_mount+0xa8/0x120
[ 1001.525784]  ? copy_mnt_ns+0xa30/0xa30
[ 1001.529693]  do_syscall_64+0x1d5/0x640
[ 1001.533647]  entry_SYSCALL_64_after_hwframe+0x46/0xbb
[ 1001.538818] RIP: 0033:0x445b2a
[ 1001.542025] RSP: 002b:00007ffda85bc928 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
[ 1001.549721] RAX: ffffffffffffffda RBX: 00007ffda85bc980 RCX: 0000000000445b2a
[ 1001.557561] RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007ffda85bc940
[ 1001.564899] RBP: 00007ffda85bc940 R08: 00007ffda85bc980 R09: 0000000000000000
[ 1001.572197] R10: 0000000000000000 R11: 0000000000000202 R12: 00000000200003f8
[ 1001.579446] R13: 0000000000000003 R14: 0000000000000004 R15: 0000000000000005
[ 1001.586751] 
[ 1001.586751] Showing all locks held in the system:
[ 1001.593104] 1 lock held by khungtaskd/1533:
[ 1001.597452]  #0:  (tasklist_lock){.+.+}, at: [<ffffffff87012a3c>] debug_show_all_locks+0x7c/0x21a
[ 1001.606530] 1 lock held by syz-executor465/7959:
[ 1001.611265]  #0:  (&type->s_umount_key#25/1){+.+.}, at: [<ffffffff81874346>] sget_userns+0x556/0xc10
[ 1001.620584] 
[ 1001.622242] =============================================
[ 1001.622242] 
[ 1001.629239] NMI backtrace for cpu 0
[ 1001.632889] CPU: 0 PID: 1533 Comm: khungtaskd Not tainted 4.14.243-syzkaller #0
[ 1001.640315] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 1001.649643] Call Trace:
[ 1001.652204]  dump_stack+0x1b2/0x281
[ 1001.655843]  nmi_cpu_backtrace.cold+0x57/0x93
[ 1001.660312]  ? irq_force_complete_move+0x350/0x350
[ 1001.665215]  nmi_trigger_cpumask_backtrace+0x13a/0x180
[ 1001.670485]  watchdog+0x5b9/0xb40
[ 1001.673912]  ? hungtask_pm_notify+0x50/0x50
[ 1001.678210]  kthread+0x30d/0x420
[ 1001.681580]  ? kthread_create_on_node+0xd0/0xd0
[ 1001.686223]  ret_from_fork+0x24/0x30
[ 1001.689991] Sending NMI from CPU 0 to CPUs 1:
[ 1001.694547] NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff8723275e
[ 1001.695974] Kernel panic - not syncing: hung_task: blocked tasks
[ 1001.707860] CPU: 0 PID: 1533 Comm: khungtaskd Not tainted 4.14.243-syzkaller #0
[ 1001.715280] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 1001.724614] Call Trace:
[ 1001.727179]  dump_stack+0x1b2/0x281
[ 1001.730778]  panic+0x1f9/0x42d
[ 1001.733943]  ? add_taint.cold+0x16/0x16
[ 1001.737894]  watchdog+0x5ca/0xb40
[ 1001.741327]  ? hungtask_pm_notify+0x50/0x50
[ 1001.745626]  kthread+0x30d/0x420
[ 1001.748966]  ? kthread_create_on_node+0xd0/0xd0
[ 1001.753605]  ret_from_fork+0x24/0x30
[ 1001.758619] Kernel Offset: disabled
[ 1001.762231] Rebooting in 86400 seconds..