[ OK ] Started OpenBSD Secure Shell server. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.192' (ECDSA) to the list of known hosts. syzkaller login: [ 475.891600][ T6830] block nbd0: shutting down sockets [ 506.374498][ T2452] block nbd0: Possible stuck request 00000000c159db0a: control (read@0,4096B). Runtime 30 seconds [ 536.450872][ T2452] block nbd0: Possible stuck request 00000000c159db0a: control (read@0,4096B). Runtime 60 seconds [ 566.527625][ T2452] block nbd0: Possible stuck request 00000000c159db0a: control (read@0,4096B). Runtime 90 seconds [ 596.604776][ T2452] block nbd0: Possible stuck request 00000000c159db0a: control (read@0,4096B). Runtime 120 seconds [ 626.682162][ T2452] block nbd0: Possible stuck request 00000000c159db0a: control (read@0,4096B). Runtime 150 seconds [ 636.921395][ T1169] INFO: task syz-executor238:6839 blocked for more than 143 seconds. [ 636.929561][ T1169] Not tainted 5.9.0-rc3-syzkaller #0 [ 636.935664][ T1169] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 636.944420][ T1169] task:syz-executor238 state:D stack:27968 pid: 6839 ppid: 6828 flags:0x00004004 [ 636.953666][ T1169] Call Trace: [ 636.957077][ T1169] __schedule+0x9b9/0xd20 [ 636.961477][ T1169] ? schedule+0x188/0x220 [ 636.965801][ T1169] ? io_schedule+0x86/0xf0 [ 636.970311][ T1169] ? wait_on_page_bit_common+0xa8c/0xd40 [ 636.976006][ T1169] ? trace_mm_filemap_add_to_page_cache+0x270/0x270 [ 636.982676][ T1169] ? do_read_cache_page+0x2e0/0xd00 [ 636.987996][ T1169] ? read_part_sector+0xd8/0x2d0 [ 636.993879][ T1169] ? vsnprintf+0x1a12/0x1aa0 [ 636.998514][ T1169] ? adfspart_check_ICS+0x45/0x640 [ 637.003696][ T1169] ? snprintf+0x6f/0x90 [ 637.007843][ T1169] ? disk_name+0x1c/0xe0 [ 637.012149][ T1169] ? vsnprintf+0x1a08/0x1aa0 [ 637.016729][ T1169] ? vsnprintf+0x142/0x1aa0 [ 637.021306][ T1169] ? blk_add_partitions+0x3ce/0x1240 [ 637.026661][ T1169] ? bdev_disk_changed+0x400/0x540 [ 637.031835][ T1169] ? __blkdev_get+0x5f1/0x1700 [ 637.036598][ T1169] ? blkdev_open+0x1c5/0x2e0 [ 637.041260][ T1169] ? block_ioctl+0x100/0x100 [ 637.045939][ T1169] ? do_dentry_open+0x7c8/0x1010 [ 637.050880][ T1169] ? path_openat+0x2794/0x3840 [ 637.055792][ T1169] ? lock_is_held_type+0xb3/0xe0 [ 637.060724][ T1169] ? lock_is_held_type+0xb3/0xe0 [ 637.065731][ T1169] ? do_filp_open+0x191/0x3a0 [ 637.070453][ T1169] ? _raw_spin_unlock+0x24/0x40 [ 637.075419][ T1169] ? __alloc_fd+0x55c/0x600 [ 637.079947][ T1169] ? do_sys_openat2+0x463/0x830 [ 637.084894][ T1169] ? __x64_sys_open+0x1af/0x1e0 [ 637.089737][ T1169] ? do_syscall_64+0x31/0x70 [ 637.094379][ T1169] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 637.100460][ T1169] [ 637.100460][ T1169] Showing all locks held in the system: [ 637.108414][ T1169] 1 lock held by khungtaskd/1169: [ 637.113505][ T1169] #0: ffffffff894fe510 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 [ 637.123651][ T1169] 1 lock held by in:imklog/6497: [ 637.128570][ T1169] #0: ffff88809ebce670 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x253/0x2f0 [ 637.137832][ T1169] 1 lock held by syz-executor238/6839: [ 637.143352][ T1169] #0: ffff88808b3fe300 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x2dd/0x1700 [ 637.152941][ T1169] [ 637.155262][ T1169] ============================================= [ 637.155262][ T1169] [ 637.163763][ T1169] NMI backtrace for cpu 0 [ 637.168094][ T1169] CPU: 0 PID: 1169 Comm: khungtaskd Not tainted 5.9.0-rc3-syzkaller #0 [ 637.176305][ T1169] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 637.186352][ T1169] Call Trace: [ 637.189699][ T1169] dump_stack+0x1d6/0x29e [ 637.194008][ T1169] nmi_cpu_backtrace+0x9f/0x180 [ 637.198887][ T1169] ? arch_trigger_cpumask_backtrace+0x10/0x10 [ 637.204943][ T1169] nmi_trigger_cpumask_backtrace+0x16a/0x280 [ 637.210930][ T1169] watchdog+0xd65/0xdb0 [ 637.215105][ T1169] kthread+0x37e/0x3a0 [ 637.219147][ T1169] ? hungtask_pm_notify+0x50/0x50 [ 637.224142][ T1169] ? kthread_blkcg+0xd0/0xd0 [ 637.228758][ T1169] ret_from_fork+0x1f/0x30 [ 637.233267][ T1169] Sending NMI from CPU 0 to CPUs 1: [ 637.238815][ C1] NMI backtrace for cpu 1 [ 637.238818][ C1] CPU: 1 PID: 3895 Comm: systemd-journal Not tainted 5.9.0-rc3-syzkaller #0 [ 637.238822][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 637.238824][ C1] RIP: 0010:rcu_is_watching+0x51/0x90 [ 637.238830][ C1] Code: 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 b4 c9 52 00 48 c7 c3 a0 67 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 8a 04 38 <84> c0 75 1d 8b 03 65 ff 0d 5e f3 9f 7e 74 0b 83 e0 02 d1 e8 5b 41 [ 637.238832][ C1] RSP: 0018:ffffc90001517c30 EFLAGS: 00000802 [ 637.238837][ C1] RAX: 1ffff11015d26c00 RBX: ffff8880ae9367a0 RCX: ffff888093192200 [ 637.238840][ C1] RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000 [ 637.238843][ C1] RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff131e236 [ 637.238845][ C1] R10: fffffbfff131e236 R11: 0000000000000000 R12: ffff888092810000 [ 637.238853][ C1] R13: 0000000000000000 R14: ffffffff892e9898 R15: dffffc0000000000 [ 637.238856][ C1] FS: 00007fbf693f48c0(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 [ 637.238859][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 637.238862][ C1] CR2: 00007fbf66793000 CR3: 000000009430f000 CR4: 00000000001506e0 [ 637.238865][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 637.238867][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 637.238869][ C1] Call Trace: [ 637.238871][ C1] rcu_read_lock_sched_held+0x11/0xa0 [ 637.238873][ C1] trace_lock_acquire+0x170/0x1d0 [ 637.238875][ C1] lock_acquire+0x47/0x6f0 [ 637.238877][ C1] ? devkmsg_read+0x15a/0xb60 [ 637.238879][ C1] ? check_preemption_disabled+0x51/0x140 [ 637.238881][ C1] _raw_spin_lock+0x2a/0x40 [ 637.238883][ C1] ? devkmsg_read+0x15a/0xb60 [ 637.238885][ C1] devkmsg_read+0x15a/0xb60 [ 637.238905][ C1] ? bpf_prog_run_pin_on_cpu+0x16f/0x190 [ 637.238907][ C1] ? __fsnotify_parent+0x2ea/0x620 [ 637.238909][ C1] ? devkmsg_llseek+0x2a0/0x2a0 [ 637.238911][ C1] vfs_read+0x243/0xb40 [ 637.238913][ C1] ? rcu_lock_release+0x5/0x20 [ 637.238915][ C1] ? __fdget_pos+0x1dd/0x2f0 [ 637.238917][ C1] ksys_read+0x11b/0x220 [ 637.238919][ C1] do_syscall_64+0x31/0x70 [ 637.238922][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 637.238924][ C1] RIP: 0033:0x7fbf68984210 [ 637.238930][ C1] Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 [ 637.238932][ C1] RSP: 002b:00007ffcf89b3c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 637.238956][ C1] RAX: ffffffffffffffda RBX: 00007ffcf89b66d0 RCX: 00007fbf68984210 [ 637.238959][ C1] RDX: 0000000000002000 RSI: 00007ffcf89b44d0 RDI: 0000000000000009 [ 637.238962][ C1] RBP: 0000000000000000 R08: 0000000000000008 R09: 0000556be2c857b8 [ 637.238965][ C1] R10: 0000556be2c85780 R11: 0000000000000246 R12: 00007ffcf89b44d0 [ 637.238968][ C1] R13: 00007ffcf89b6628 R14: 0000556be1fc4958 R15: 0005ae3fade82d6a [ 637.239491][ T1169] Kernel panic - not syncing: hung_task: blocked tasks [ 637.536757][ T1169] CPU: 0 PID: 1169 Comm: khungtaskd Not tainted 5.9.0-rc3-syzkaller #0 [ 637.544972][ T1169] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 637.555014][ T1169] Call Trace: [ 637.558283][ T1169] dump_stack+0x1d6/0x29e [ 637.562663][ T1169] panic+0x2c0/0x800 [ 637.566531][ T1169] ? nmi_trigger_cpumask_backtrace+0x206/0x280 [ 637.572673][ T1169] ? arch_trigger_cpumask_backtrace+0x10/0x10 [ 637.578711][ T1169] watchdog+0xda5/0xdb0 [ 637.582845][ T1169] kthread+0x37e/0x3a0 [ 637.586887][ T1169] ? hungtask_pm_notify+0x50/0x50 [ 637.591881][ T1169] ? kthread_blkcg+0xd0/0xd0 [ 637.596458][ T1169] ret_from_fork+0x1f/0x30 [ 637.602353][ T1169] Kernel Offset: disabled [ 637.606689][ T1169] Rebooting in 86400 seconds..