[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.15.206' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 758.606668] block nbd0: shutting down sockets [ 1001.408131] INFO: task syz-executor744:8024 blocked for more than 140 seconds. [ 1001.415598] Not tainted 4.14.217-syzkaller #0 [ 1001.420734] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1001.429076] syz-executor744 D28216 8024 8023 0x00000004 [ 1001.434715] Call Trace: [ 1001.437357] __schedule+0x88b/0x1de0 [ 1001.441219] ? trace_hardirqs_on+0x10/0x10 [ 1001.445571] ? io_schedule_timeout+0x140/0x140 [ 1001.450279] ? trace_hardirqs_on+0x10/0x10 [ 1001.454894] schedule+0x8d/0x1b0 [ 1001.458816] schedule_timeout+0x80a/0xe90 [ 1001.463278] ? trace_hardirqs_on+0x10/0x10 [ 1001.468601] ? usleep_range+0x130/0x130 [ 1001.473173] ? flush_workqueue+0x129/0x1310 [ 1001.477673] ? wait_for_common+0x26a/0x430 [ 1001.481957] ? lock_acquire+0x170/0x3f0 [ 1001.485936] ? lock_downgrade+0x740/0x740 [ 1001.490151] ? _raw_spin_unlock_irq+0x24/0x80 [ 1001.494655] wait_for_common+0x272/0x430 [ 1001.498757] ? out_of_line_wait_on_atomic_t+0x1a0/0x1a0 [ 1001.504113] ? __mutex_unlock_slowpath+0x75/0x770 [ 1001.509085] ? wake_up_q+0xd0/0xd0 [ 1001.512734] ? flush_workqueue_prep_pwqs+0x31f/0x470 [ 1001.517823] ? check_flush_dependency+0x4a/0x2a0 [ 1001.522662] flush_workqueue+0x3ce/0x1310 [ 1001.526809] ? check_flush_dependency+0x2a0/0x2a0 [ 1001.531729] ? wait_for_completion_io+0x10/0x10 [ 1001.536458] nbd_ioctl+0x49d/0xa80 [ 1001.540088] ? nbd_disconnect_and_put+0x140/0x140 [ 1001.544948] ? wait_woken+0x230/0x230 [ 1001.548815] ? nbd_disconnect_and_put+0x140/0x140 [ 1001.553740] blkdev_ioctl+0x540/0x1830 [ 1001.557669] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 1001.563187] ? blkpg_ioctl+0x8d0/0x8d0 [ 1001.567208] ? trace_hardirqs_on+0x10/0x10 [ 1001.571532] ? trace_hardirqs_on+0x10/0x10 [ 1001.575964] block_ioctl+0xd9/0x120 [ 1001.579650] ? blkdev_fallocate+0x3a0/0x3a0 [ 1001.584020] do_vfs_ioctl+0x75a/0xff0 [ 1001.587820] ? ioctl_preallocate+0x1a0/0x1a0 [ 1001.592365] ? __fd_install+0x227/0x5c0 [ 1001.596370] ? get_unused_fd_flags+0xc0/0xc0 [ 1001.601136] ? _raw_spin_unlock+0x29/0x40 [ 1001.605471] ? __alloc_fd+0x1be/0x490 [ 1001.609487] ? security_file_ioctl+0x83/0xb0 [ 1001.614142] SyS_ioctl+0x7f/0xb0 [ 1001.617533] ? do_vfs_ioctl+0xff0/0xff0 [ 1001.622164] do_syscall_64+0x1d5/0x640 [ 1001.626703] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 1001.632077] RIP: 0033:0x444f39 [ 1001.635661] RSP: 002b:00007ffdb7374f98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 1001.643452] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444f39 [ 1001.651081] RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 [ 1001.658620] RBP: 00000000006cf018 R08: 00000000004002e0 R09: 00000000004002e0 [ 1001.666125] R10: 00000000004002e0 R11: 0000000000000246 R12: 0000000000402100 [ 1001.674392] R13: 0000000000402190 R14: 0000000000000000 R15: 0000000000000000 [ 1001.681807] [ 1001.681807] Showing all locks held in the system: [ 1001.688776] 1 lock held by khungtaskd/1531: [ 1001.693206] #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a [ 1001.702389] 2 locks held by kworker/u5:0/1675: [ 1001.707326] #0: ("knbd%d-recv"nbd->index){+.+.}, at: [] process_one_work+0x6b0/0x14a0 [ 1001.717645] #1: ((&args->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 [ 1001.726946] 1 lock held by in:imklog/7711: [ 1001.731373] #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 [ 1001.740190] [ 1001.741826] ============================================= [ 1001.741826] [ 1001.748924] NMI backtrace for cpu 1 [ 1001.752832] CPU: 1 PID: 1531 Comm: khungtaskd Not tainted 4.14.217-syzkaller #0 [ 1001.760279] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 1001.769633] Call Trace: [ 1001.772410] dump_stack+0x1b2/0x281 [ 1001.776035] nmi_cpu_backtrace.cold+0x57/0x93 [ 1001.780731] ? irq_force_complete_move+0x350/0x350 [ 1001.785861] nmi_trigger_cpumask_backtrace+0x13a/0x180 [ 1001.791294] watchdog+0x5b9/0xb40 [ 1001.794742] ? hungtask_pm_notify+0x50/0x50 [ 1001.799209] kthread+0x30d/0x420 [ 1001.802566] ? kthread_create_on_node+0xd0/0xd0 [ 1001.807247] ret_from_fork+0x24/0x30 [ 1001.811135] Sending NMI from CPU 1 to CPUs 0: [ 1001.816296] NMI backtrace for cpu 0 [ 1001.816300] CPU: 0 PID: 4626 Comm: systemd-journal Not tainted 4.14.217-syzkaller #0 [ 1001.816305] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 1001.816308] task: ffff8880a118a1c0 task.stack: ffff8880a1190000 [ 1001.816311] RIP: 0010:link_path_walk+0x1ea/0x10a0 [ 1001.816314] RSP: 0018:ffff8880a1197ae8 EFLAGS: 00000246 [ 1001.816319] RAX: ffff8880b58162c0 RBX: ffff8880b58162c0 RCX: 0000000000000001 [ 1001.816323] RDX: 0000000000000000 RSI: 0000000000000000 RDI: dffffc0000000000 [ 1001.816326] RBP: 0000000000000000 R08: ffffffff8b9c2788 R09: 0000000000000000 [ 1001.816330] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a1197cf8 [ 1001.816333] R13: fefefefefefefeff R14: 0000000000000000 R15: ffff888094eec9e5 [ 1001.816337] FS: 00007f1c166218c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 [ 1001.816340] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1001.816343] CR2: 00007f1c139f7000 CR3: 00000000a1049000 CR4: 00000000001406f0 [ 1001.816347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1001.816350] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1001.816352] Call Trace: [ 1001.816355] ? walk_component+0xbc0/0xbc0 [ 1001.816357] path_openat+0x15e/0x2970 [ 1001.816359] ? path_lookupat+0x780/0x780 [ 1001.816362] ? trace_hardirqs_on+0x10/0x10 [ 1001.816364] ? getname+0x20/0x20 [ 1001.816366] do_filp_open+0x179/0x3c0 [ 1001.816369] ? may_open_dev+0xe0/0xe0 [ 1001.816371] ? lock_downgrade+0x740/0x740 [ 1001.816374] ? do_raw_spin_unlock+0x164/0x220 [ 1001.816376] ? _raw_spin_unlock+0x29/0x40 [ 1001.816379] ? __alloc_fd+0x1be/0x490 [ 1001.816381] do_sys_open+0x296/0x410 [ 1001.816383] ? filp_open+0x60/0x60 [ 1001.816386] ? do_syscall_64+0x4c/0x640 [ 1001.816388] ? do_sys_open+0x410/0x410 [ 1001.816390] do_syscall_64+0x1d5/0x640 [ 1001.816393] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 1001.816395] RIP: 0033:0x7f1c15bb1840 [ 1001.816398] RSP: 002b:00007ffc835fb098 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 1001.816404] RAX: ffffffffffffffda RBX: 00007ffc835fb3a0 RCX: 00007f1c15bb1840 [ 1001.816408] RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005617e738df30 [ 1001.816411] RBP: 000000000000000d R08: 000000000000c0c1 R09: 00000000ffffffff [ 1001.816415] R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff [ 1001.816418] R13: 00005617e7381040 R14: 00007ffc835fb360 R15: 00005617e738dd50 [ 1001.816420] Code: fe fe fe 48 89 44 24 10 48 89 c3 eb 1e e8 0f 91 cb ff 4d 31 e6 48 83 c5 08 4c 31 f3 49 c1 c6 0c 49 01 de 48 c1 cb 13 48 8d 1c db f1 90 cb ff 48 ba 2f 2f 2f 2f 2f 2f 2f 2f 48 b8 80 80 80 80 [ 1001.816752] Kernel panic - not syncing: hung_task: blocked tasks [ 1002.080939] CPU: 1 PID: 1531 Comm: khungtaskd Not tainted 4.14.217-syzkaller #0 [ 1002.088570] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 1002.097949] Call Trace: [ 1002.100816] dump_stack+0x1b2/0x281 [ 1002.105185] panic+0x1f9/0x42d [ 1002.108391] ? add_taint.cold+0x16/0x16 [ 1002.114880] ? printk_safe_flush+0xa9/0x110 [ 1002.119896] watchdog+0x5ca/0xb40 [ 1002.124204] ? hungtask_pm_notify+0x50/0x50 [ 1002.128525] kthread+0x30d/0x420 [ 1002.132110] ? kthread_create_on_node+0xd0/0xd0 [ 1002.136880] ret_from_fork+0x24/0x30 [ 1002.141174] Kernel Offset: disabled [ 1002.144818] Rebooting in 86400 seconds..