[ OK ] Started OpenBSD Secure Shell server. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.74' (ECDSA) to the list of known hosts. syzkaller login: [ 476.183432][ T6819] block nbd0: shutting down sockets [ 506.302696][ T2452] block nbd0: Possible stuck request 00000000fed23df5: control (read@0,4096B). Runtime 30 seconds [ 536.379085][ T2452] block nbd0: Possible stuck request 00000000fed23df5: control (read@0,4096B). Runtime 60 seconds [ 566.455968][ T2452] block nbd0: Possible stuck request 00000000fed23df5: control (read@0,4096B). Runtime 90 seconds [ 596.533179][ T2452] block nbd0: Possible stuck request 00000000fed23df5: control (read@0,4096B). Runtime 120 seconds [ 626.610647][ T2452] block nbd0: Possible stuck request 00000000fed23df5: control (read@0,4096B). Runtime 150 seconds [ 636.849885][ T1168] INFO: task syz-executor678:6828 blocked for more than 143 seconds. [ 636.858135][ T1168] Not tainted 5.9.0-rc1-syzkaller #0 [ 636.864470][ T1168] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 636.873256][ T1168] task:syz-executor678 state:D stack:27968 pid: 6828 ppid: 6817 flags:0x00004004 [ 636.882501][ T1168] Call Trace: [ 636.885988][ T1168] __schedule+0x979/0xce0 [ 636.890394][ T1168] ? schedule+0x188/0x220 [ 636.894721][ T1168] ? io_schedule+0x86/0xf0 [ 636.899203][ T1168] ? wait_on_page_bit_common+0xa8c/0xd40 [ 636.904976][ T1168] ? trace_mm_filemap_add_to_page_cache+0x270/0x270 [ 636.911644][ T1168] ? do_read_cache_page+0x2e0/0xd00 [ 636.916907][ T1168] ? read_part_sector+0xd8/0x2d0 [ 636.922095][ T1168] ? vsnprintf+0x1a12/0x1aa0 [ 636.926765][ T1168] ? adfspart_check_ICS+0x45/0x640 [ 636.932017][ T1168] ? snprintf+0x6f/0x90 [ 636.936170][ T1168] ? disk_name+0x1c/0xe0 [ 636.940531][ T1168] ? vsnprintf+0x1a08/0x1aa0 [ 636.945176][ T1168] ? vsnprintf+0x142/0x1aa0 [ 636.949768][ T1168] ? blk_add_partitions+0x3ce/0x1240 [ 636.955132][ T1168] ? bdev_disk_changed+0x400/0x540 [ 636.960312][ T1168] ? __blkdev_get+0x5f1/0x1700 [ 636.965082][ T1168] ? blkdev_open+0x1c5/0x2e0 [ 636.969742][ T1168] ? block_ioctl+0x100/0x100 [ 636.974409][ T1168] ? do_dentry_open+0x7c8/0x1010 [ 636.979490][ T1168] ? path_openat+0x2794/0x3840 [ 636.984390][ T1168] ? do_filp_open+0x191/0x3a0 [ 636.989144][ T1168] ? _raw_spin_unlock+0x24/0x40 [ 636.994148][ T1168] ? __alloc_fd+0x55c/0x600 [ 636.998661][ T1168] ? do_sys_openat2+0x463/0x830 [ 637.003578][ T1168] ? __x64_sys_open+0x1af/0x1e0 [ 637.008534][ T1168] ? do_syscall_64+0x31/0x70 [ 637.013224][ T1168] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 637.019310][ T1168] INFO: task syz-executor678:6829 blocked for more than 143 seconds. [ 637.027442][ T1168] Not tainted 5.9.0-rc1-syzkaller #0 [ 637.033499][ T1168] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 637.042206][ T1168] task:syz-executor678 state:D stack:28576 pid: 6829 ppid: 6817 flags:0x00004004 [ 637.051484][ T1168] Call Trace: [ 637.054769][ T1168] __schedule+0x979/0xce0 [ 637.059165][ T1168] ? schedule+0x188/0x220 [ 637.063681][ T1168] ? schedule_preempt_disabled+0xf/0x20 [ 637.069216][ T1168] ? __mutex_lock_common+0x129f/0x2fc0 [ 637.074833][ T1168] ? __blkdev_get+0x2dd/0x1700 [ 637.079672][ T1168] ? mutex_lock_nested+0x1a/0x20 [ 637.084605][ T1168] ? __blkdev_get+0x2dd/0x1700 [ 637.089372][ T1168] ? bd_acquire+0x531/0x650 [ 637.093947][ T1168] ? blkdev_open+0x1c5/0x2e0 [ 637.098532][ T1168] ? block_ioctl+0x100/0x100 [ 637.103169][ T1168] ? do_dentry_open+0x7c8/0x1010 [ 637.108108][ T1168] ? path_openat+0x2794/0x3840 [ 637.112969][ T1168] ? do_filp_open+0x191/0x3a0 [ 637.117642][ T1168] ? _raw_spin_unlock+0x24/0x40 [ 637.122537][ T1168] ? __alloc_fd+0x55c/0x600 [ 637.127060][ T1168] ? do_sys_openat2+0x463/0x830 [ 637.131970][ T1168] ? __x64_sys_open+0x1af/0x1e0 [ 637.136818][ T1168] ? do_syscall_64+0x31/0x70 [ 637.141451][ T1168] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 637.147534][ T1168] [ 637.147534][ T1168] Showing all locks held in the system: [ 637.155323][ T1168] 1 lock held by khungtaskd/1168: [ 637.160435][ T1168] #0: ffffffff894fe510 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 [ 637.169945][ T1168] 1 lock held by syz-executor678/6828: [ 637.175394][ T1168] #0: ffff88808afad380 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x2dd/0x1700 [ 637.184924][ T1168] 1 lock held by syz-executor678/6829: [ 637.190450][ T1168] #0: ffff88808afad380 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x2dd/0x1700 [ 637.200006][ T1168] [ 637.202325][ T1168] ============================================= [ 637.202325][ T1168] [ 637.211175][ T1168] NMI backtrace for cpu 0 [ 637.215602][ T1168] CPU: 0 PID: 1168 Comm: khungtaskd Not tainted 5.9.0-rc1-syzkaller #0 [ 637.223808][ T1168] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 637.233875][ T1168] Call Trace: [ 637.237152][ T1168] dump_stack+0x1f0/0x31e [ 637.241466][ T1168] nmi_cpu_backtrace+0x9f/0x180 [ 637.246405][ T1168] ? arch_trigger_cpumask_backtrace+0x10/0x10 [ 637.252465][ T1168] nmi_trigger_cpumask_backtrace+0x16a/0x280 [ 637.258465][ T1168] watchdog+0xd65/0xdb0 [ 637.262687][ T1168] kthread+0x37e/0x3a0 [ 637.266729][ T1168] ? hungtask_pm_notify+0x50/0x50 [ 637.271758][ T1168] ? kthread_blkcg+0xd0/0xd0 [ 637.276386][ T1168] ret_from_fork+0x1f/0x30 [ 637.280920][ T1168] Sending NMI from CPU 0 to CPUs 1: [ 637.286184][ C1] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 [ 637.287158][ T1168] Kernel panic - not syncing: hung_task: blocked tasks [ 637.301253][ T1168] CPU: 0 PID: 1168 Comm: khungtaskd Not tainted 5.9.0-rc1-syzkaller #0 [ 637.309469][ T1168] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 637.319497][ T1168] Call Trace: [ 637.322766][ T1168] dump_stack+0x1f0/0x31e [ 637.327138][ T1168] panic+0x264/0x7a0 [ 637.331007][ T1168] ? nmi_trigger_cpumask_backtrace+0x206/0x280 [ 637.337132][ T1168] watchdog+0xda5/0xdb0 [ 637.341263][ T1168] kthread+0x37e/0x3a0 [ 637.345387][ T1168] ? hungtask_pm_notify+0x50/0x50 [ 637.350390][ T1168] ? kthread_blkcg+0xd0/0xd0 [ 637.354978][ T1168] ret_from_fork+0x1f/0x30 [ 637.360849][ T1168] Kernel Offset: disabled [ 637.365179][ T1168] Rebooting in 86400 seconds..