Warning: Permanently added '10.128.0.253' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [  840.200232][ T8456] NILFS (loop0): broken superblock, retrying with spare superblock (blocksize = 1024)
[  840.211561][ T8456] NILFS (loop0): broken superblock, retrying with spare superblock (blocksize = 2048)
[  840.223223][ T8456] NILFS (loop0): mounting unchecked fs
[  840.235351][ T8456] NILFS (loop0): recovery complete
[  840.242824][ T8462] NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
[ 1002.586529][ T1640] INFO: task syz-executor266:8455 blocked for more than 143 seconds.
[ 1002.594981][ T1640]       Not tainted 5.10.0-rc6-syzkaller #0
[ 1002.602426][ T1640] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1002.611208][ T1640] task:syz-executor266 state:D stack:27448 pid: 8455 ppid:  8449 flags:0x00004000
[ 1002.620506][ T1640] Call Trace:
[ 1002.623824][ T1640]  __schedule+0x893/0x2130
[ 1002.628471][ T1640]  ? io_schedule_timeout+0x140/0x140
[ 1002.633771][ T1640]  ? prepare_to_wait_event+0x129/0x650
[ 1002.639350][ T1640]  schedule+0xcf/0x270
[ 1002.643436][ T1640]  wb_wait_for_completion+0x17b/0x230
[ 1002.648902][ T1640]  ? sync_inode_metadata+0xd0/0xd0
[ 1002.654044][ T1640]  ? add_wait_queue_exclusive+0x180/0x180
[ 1002.659877][ T1640]  ? down_write_killable+0x170/0x170
[ 1002.665292][ T1640]  sync_inodes_sb+0x1a6/0x9d0
[ 1002.670088][ T1640]  ? I_BDEV+0x9/0x20
[ 1002.674025][ T1640]  ? __filemap_fdatawrite_range+0x1dc/0x380
[ 1002.680024][ T1640]  ? try_to_writeback_inodes_sb+0xc0/0xc0
[ 1002.685779][ T1640]  ? get_nr_dirty_inodes+0x1b2/0x250
[ 1002.691175][ T1640]  sync_filesystem+0x15c/0x260
[ 1002.696051][ T1640]  generic_shutdown_super+0x70/0x370
[ 1002.701436][ T1640]  kill_block_super+0x97/0xf0
[ 1002.706124][ T1640]  deactivate_locked_super+0x94/0x160
[ 1002.711602][ T1640]  deactivate_super+0xad/0xd0
[ 1002.716558][ T1640]  cleanup_mnt+0x3a3/0x530
[ 1002.721092][ T1640]  task_work_run+0xdd/0x190
[ 1002.725779][ T1640]  exit_to_user_mode_prepare+0x17e/0x1a0
[ 1002.731548][ T1640]  syscall_exit_to_user_mode+0x38/0x260
[ 1002.737199][ T1640]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1002.743116][ T1640] RIP: 0033:0x448617
[ 1002.747429][ T1640] RSP: 002b:00007ffe69ca89e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
[ 1002.755965][ T1640] RAX: 0000000000000000 RBX: 00007ffe69ca9b60 RCX: 0000000000448617
[ 1002.764059][ T1640] RDX: 0000000000400bb0 RSI: 0000000000000002 RDI: 00007ffe69ca8a90
[ 1002.772238][ T1640] RBP: 00000000000cd1c7 R08: 0000000000000000 R09: 0000000000000009
[ 1002.780305][ T1640] R10: 0000000000000005 R11: 0000000000000206 R12: 00007ffe69ca9b00
[ 1002.788364][ T1640] R13: 0000000000742880 R14: 0000000000000000 R15: 0000000000000000
[ 1002.796883][ T1640] 
[ 1002.796883][ T1640] Showing all locks held in the system:
[ 1002.804709][ T1640] 2 locks held by kworker/u4:0/8:
[ 1002.809823][ T1640]  #0: ffff88814155c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x821/0x15a0
[ 1002.821539][ T1640]  #1: ffffc90000cd7da8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0
[ 1002.834210][ T1640] 1 lock held by khungtaskd/1640:
[ 1002.839413][ T1640]  #0: ffffffff8b3378e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260
[ 1002.849553][ T1640] 2 locks held by syz-executor266/8455:
[ 1002.855442][ T1640]  #0: ffff88802f44a0e0 (&type->s_umount_key#48){+.+.}-{3:3}, at: deactivate_super+0xa5/0xd0
[ 1002.865793][ T1640]  #1: ffff888018e5a708 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x18c/0x9d0
[ 1002.877537][ T1640] 
[ 1002.879881][ T1640] =============================================
[ 1002.879881][ T1640] 
[ 1002.888581][ T1640] NMI backtrace for cpu 0
[ 1002.892906][ T1640] CPU: 0 PID: 1640 Comm: khungtaskd Not tainted 5.10.0-rc6-syzkaller #0
[ 1002.901206][ T1640] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 1002.911324][ T1640] Call Trace:
[ 1002.914595][ T1640]  dump_stack+0x107/0x163
[ 1002.918902][ T1640]  nmi_cpu_backtrace.cold+0x44/0xd7
[ 1002.924281][ T1640]  ? lapic_can_unplug_cpu+0x80/0x80
[ 1002.929457][ T1640]  nmi_trigger_cpumask_backtrace+0x1b3/0x230
[ 1002.935500][ T1640]  watchdog+0xd43/0xfa0
[ 1002.939633][ T1640]  ? reset_hung_task_detector+0x30/0x30
[ 1002.945243][ T1640]  kthread+0x3b1/0x4a0
[ 1002.949461][ T1640]  ? kthread_create_worker_on_cpu+0xf0/0xf0
[ 1002.955339][ T1640]  ret_from_fork+0x1f/0x30
[ 1002.959822][ T1640] Sending NMI from CPU 0 to CPUs 1:
[ 1002.965193][    C1] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x1c9/0x250
[ 1002.966115][ T1640] Kernel panic - not syncing: hung_task: blocked tasks
[ 1002.980787][ T1640] CPU: 0 PID: 1640 Comm: khungtaskd Not tainted 5.10.0-rc6-syzkaller #0
[ 1002.989081][ T1640] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 1002.999109][ T1640] Call Trace:
[ 1003.002385][ T1640]  dump_stack+0x107/0x163
[ 1003.006707][ T1640]  panic+0x306/0x73d
[ 1003.010596][ T1640]  ? __warn_printk+0xf3/0xf3
[ 1003.015165][ T1640]  ? cpumask_next+0x3c/0x40
[ 1003.019642][ T1640]  ? printk_safe_flush+0xea/0x160
[ 1003.024815][ T1640]  ? watchdog.cold+0x5/0x158
[ 1003.029380][ T1640]  ? watchdog+0xa80/0xfa0
[ 1003.033684][ T1640]  watchdog.cold+0x16/0x158
[ 1003.038181][ T1640]  ? reset_hung_task_detector+0x30/0x30
[ 1003.043818][ T1640]  kthread+0x3b1/0x4a0
[ 1003.048017][ T1640]  ? kthread_create_worker_on_cpu+0xf0/0xf0
[ 1003.054230][ T1640]  ret_from_fork+0x1f/0x30
[ 1003.062185][ T1640] Kernel Offset: disabled
[ 1003.066624][ T1640] Rebooting in 86400 seconds..