[ 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 '10.128.0.72' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 485.631040] block nbd0: shutting down sockets [ 717.767235] INFO: task syz-executor780:8076 blocked for more than 140 seconds. [ 717.774985] Not tainted 4.19.184-syzkaller #0 [ 717.781285] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 717.789843] syz-executor780 D27504 8076 8075 0x80000006 [ 717.795766] Call Trace: [ 717.798435] __schedule+0x887/0x2040 [ 717.802324] ? io_schedule_timeout+0x140/0x140 [ 717.807244] ? lock_downgrade+0x720/0x720 [ 717.811491] ? __mutex_lock+0x458/0x1260 [ 717.815698] schedule+0x8d/0x1b0 [ 717.819237] schedule_preempt_disabled+0xf/0x20 [ 717.824046] __mutex_lock+0x647/0x1260 [ 717.828000] ? blkdev_put+0x30/0x520 [ 717.831720] ? __mutex_add_waiter+0x160/0x160 [ 717.836364] ? lock_downgrade+0x720/0x720 [ 717.840700] ? locks_remove_file+0x286/0x450 [ 717.845122] ? locks_check_ctx_file_list+0x1d/0x110 [ 717.850211] ? _raw_spin_unlock+0x29/0x40 [ 717.854368] ? locks_remove_file+0x2cd/0x450 [ 717.858832] ? blkdev_put+0x520/0x520 [ 717.862760] blkdev_put+0x30/0x520 [ 717.866295] ? blkdev_put+0x520/0x520 [ 717.870153] blkdev_close+0x86/0xb0 [ 717.873789] __fput+0x2ce/0x890 [ 717.877805] task_work_run+0x148/0x1c0 [ 717.881750] do_exit+0xbf3/0x2be0 [ 717.885202] ? mm_update_next_owner+0x650/0x650 [ 717.889935] ? get_signal+0x388/0x1f70 [ 717.893949] ? lock_downgrade+0x720/0x720 [ 717.898190] ? lock_acquire+0x170/0x3c0 [ 717.902281] do_group_exit+0x125/0x310 [ 717.906187] get_signal+0x3f2/0x1f70 [ 717.909979] do_signal+0x8f/0x1670 [ 717.913531] ? block_ioctl+0xe9/0x130 [ 717.917376] ? blkdev_fallocate+0x3f0/0x3f0 [ 717.922049] ? do_vfs_ioctl+0x110/0x12e0 [ 717.926103] ? setup_sigcontext+0x820/0x820 [ 717.930500] ? debug_check_no_obj_freed+0x201/0x490 [ 717.935558] ? ioctl_preallocate+0x200/0x200 [ 717.940023] ? putname+0xe1/0x120 [ 717.943538] ? putname+0xe1/0x120 [ 717.947064] ? rcu_read_lock_sched_held+0x16c/0x1d0 [ 717.952084] ? kmem_cache_free+0x226/0x260 [ 717.956310] ? putname+0xe1/0x120 [ 717.959845] ? do_sys_open+0x2bf/0x520 [ 717.963852] ? filp_open+0x70/0x70 [ 717.967461] ? exit_to_usermode_loop+0x36/0x2a0 [ 717.972314] exit_to_usermode_loop+0x204/0x2a0 [ 717.976886] do_syscall_64+0x538/0x620 [ 717.980839] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 717.986034] RIP: 0033:0x444249 [ 717.989274] Code: Bad RIP value. [ 717.992638] RSP: 002b:00007fff6900ff48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 718.000414] RAX: fffffffffffffe00 RBX: 00000000004004a0 RCX: 0000000000444249 [ 718.008165] RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 [ 718.015436] RBP: 0000000000000000 R08: 00007fff690100e8 R09: 00007fff690100e8 [ 718.022784] R10: 002364626e2f7665 R11: 0000000000000246 R12: 0000000000403560 [ 718.030110] R13: 431bde82d7b634db R14: 00000000004b2018 R15: 00000000004004a0 [ 718.037475] INFO: task systemd-udevd:8079 blocked for more than 140 seconds. [ 718.044925] Not tainted 4.19.184-syzkaller #0 [ 718.049998] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 718.058033] systemd-udevd D26624 8079 4701 0x00000104 [ 718.069705] Call Trace: [ 718.072351] __schedule+0x887/0x2040 [ 718.080478] ? io_schedule_timeout+0x140/0x140 [ 718.085065] schedule+0x8d/0x1b0 [ 718.088477] io_schedule+0xb5/0x120 [ 718.092130] wait_on_page_bit+0x2c5/0x3f0 [ 718.096263] ? wake_page_function+0x1b0/0x1b0 [ 718.100886] ? __bread_gfp+0x300/0x300 [ 718.104778] ? add_to_page_cache_lru+0x680/0x680 [ 718.112281] do_read_cache_page+0x8ed/0x1170 [ 718.116693] ? blkdev_writepages+0x20/0x20 [ 718.120995] read_dev_sector+0xbf/0x500 [ 718.124985] ? adfspart_check_ADFS+0x8e0/0x8e0 [ 718.129614] adfspart_check_ICS+0x114/0xe70 [ 718.133946] ? adfspart_check_ADFS+0x8e0/0x8e0 [ 718.139262] ? snprintf+0xbb/0xf0 [ 718.142748] ? vsprintf+0x30/0x30 [ 718.146202] ? _raw_spin_unlock+0x29/0x40 [ 718.150403] ? __get_vm_area_node+0x2e2/0x3a0 [ 718.154915] ? adfspart_check_ADFS+0x8e0/0x8e0 [ 718.159558] check_partition+0x390/0x690 [ 718.163630] rescan_partitions+0x1b5/0x970 [ 718.168281] ? nbd_open+0x4cc/0x6f0 [ 718.171914] ? nbd_add_socket+0x840/0x840 [ 718.176053] bdev_disk_changed+0x179/0x1b0 [ 718.180342] __blkdev_get+0x1282/0x1480 [ 718.184322] ? bdev_disk_changed+0x1b0/0x1b0 [ 718.188771] ? mark_held_locks+0xf0/0xf0 [ 718.192842] ? mark_held_locks+0xf0/0xf0 [ 718.196913] blkdev_get+0xb0/0x940 [ 718.200508] ? bd_acquire+0x245/0x440 [ 718.204309] ? __blkdev_get+0x1480/0x1480 [ 718.208500] ? lock_downgrade+0x720/0x720 [ 718.212649] ? lock_acquire+0x170/0x3c0 [ 718.216612] ? bd_acquire+0x21/0x440 [ 718.220379] ? do_raw_spin_unlock+0x171/0x230 [ 718.224938] blkdev_open+0x202/0x290 [ 718.228720] do_dentry_open+0x4aa/0x1160 [ 718.232793] ? blkdev_get_by_dev+0x70/0x70 [ 718.237085] ? chown_common+0x550/0x550 [ 718.241247] ? inode_permission+0x3d/0x140 [ 718.245465] path_openat+0x793/0x2df0 [ 718.249315] ? path_lookupat+0x8d0/0x8d0 [ 718.253501] ? __put_seccomp_filter+0xa0/0xa0 [ 718.258048] ? mark_held_locks+0xf0/0xf0 [ 718.262134] do_filp_open+0x18c/0x3f0 [ 718.265915] ? may_open_dev+0xf0/0xf0 [ 718.270422] ? lock_downgrade+0x720/0x720 [ 718.274581] ? lock_acquire+0x170/0x3c0 [ 718.278604] ? __alloc_fd+0x34/0x570 [ 718.282315] ? do_raw_spin_unlock+0x171/0x230 [ 718.286793] ? _raw_spin_unlock+0x29/0x40 [ 718.290976] ? __alloc_fd+0x28d/0x570 [ 718.294871] do_sys_open+0x3b3/0x520 [ 718.298629] ? filp_open+0x70/0x70 [ 718.302177] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 718.307586] ? trace_hardirqs_off_caller+0x6e/0x210 [ 718.312607] ? do_syscall_64+0x21/0x620 [ 718.316575] do_syscall_64+0xf9/0x620 [ 718.320443] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 718.325629] RIP: 0033:0x7f60999b4840 [ 718.329407] Code: Bad RIP value. [ 718.332773] RSP: 002b:00007ffcb2ac8458 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 718.340525] RAX: ffffffffffffffda RBX: 00005592a57396e0 RCX: 00007f60999b4840 [ 718.347879] RDX: 00005592a48dbfe3 RSI: 00000000000a0800 RDI: 00005592a573e1b0 [ 718.355139] RBP: 00007ffcb2ac85d0 R08: 00005592a48db670 R09: 0000000000000010 [ 718.362464] R10: 00005592a48dbd0c R11: 0000000000000246 R12: 00007ffcb2ac8520 [ 718.369886] R13: 00005592a573c880 R14: 0000000000000003 R15: 000000000000000e [ 718.377336] [ 718.377336] Showing all locks held in the system: [ 718.383818] 1 lock held by khungtaskd/1570: [ 718.388198] #0: 00000000f8cc6968 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 [ 718.396881] 1 lock held by in:imklog/7744: [ 718.401797] #0: 00000000da7bd8b0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 [ 718.409902] 1 lock held by syz-executor780/8076: [ 718.414652] #0: 000000007e169559 (&bdev->bd_mutex){+.+.}, at: blkdev_put+0x30/0x520 [ 718.422593] 1 lock held by systemd-udevd/8079: [ 718.427212] #0: 000000007e169559 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x1d0/0x1480 [ 718.435464] [ 718.437148] ============================================= [ 718.437148] [ 718.444166] NMI backtrace for cpu 0 [ 718.447862] CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.184-syzkaller #0 [ 718.455313] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 718.464666] Call Trace: [ 718.467254] dump_stack+0x1fc/0x2ef [ 718.470873] nmi_cpu_backtrace.cold+0x63/0xa2 [ 718.475349] ? lapic_can_unplug_cpu+0x80/0x80 [ 718.479827] nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 [ 718.485104] watchdog+0x991/0xe60 [ 718.488556] ? reset_hung_task_detector+0x30/0x30 [ 718.493384] kthread+0x33f/0x460 [ 718.496747] ? kthread_park+0x180/0x180 [ 718.500739] ret_from_fork+0x24/0x30 [ 718.504568] Sending NMI from CPU 0 to CPUs 1: [ 718.509221] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 [ 718.510177] Kernel panic - not syncing: hung_task: blocked tasks [ 718.523028] CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.184-syzkaller #0 [ 718.530548] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 718.539889] Call Trace: [ 718.542468] dump_stack+0x1fc/0x2ef [ 718.546211] panic+0x26a/0x50e [ 718.549389] ? __warn_printk+0xf3/0xf3 [ 718.553260] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 718.558346] ? cpumask_next+0x3c/0x40 [ 718.562129] ? printk_safe_flush+0xd6/0x120 [ 718.566433] ? watchdog+0x991/0xe60 [ 718.570064] ? nmi_trigger_cpumask_backtrace+0x15e/0x1f0 [ 718.575497] watchdog+0x9a2/0xe60 [ 718.578935] ? reset_hung_task_detector+0x30/0x30 [ 718.583757] kthread+0x33f/0x460 [ 718.587189] ? kthread_park+0x180/0x180 [ 718.591144] ret_from_fork+0x24/0x30 [ 718.595645] Kernel Offset: disabled [ 718.599267] Rebooting in 86400 seconds..