[ 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 '10.128.0.61' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 1001.333471] INFO: task systemd-udevd:8090 blocked for more than 140 seconds. [ 1001.340893] Not tainted 4.14.218-syzkaller #0 [ 1001.347608] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1001.355869] systemd-udevd D28712 8090 4630 0x00000104 [ 1001.361601] Call Trace: [ 1001.364332] __schedule+0x88b/0x1de0 [ 1001.368048] ? io_schedule_timeout+0x140/0x140 [ 1001.372656] ? lock_downgrade+0x740/0x740 [ 1001.376960] schedule+0x8d/0x1b0 [ 1001.380394] schedule_preempt_disabled+0xf/0x20 [ 1001.385144] __mutex_lock+0x669/0x1310 [ 1001.389123] ? __blkdev_get+0x191/0x1090 [ 1001.393230] ? __mutex_lock+0x310/0x1310 [ 1001.397333] ? lo_open+0x19/0xb0 [ 1001.400697] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 1001.406189] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 1001.411633] ? exact_match+0x9/0x20 [ 1001.415442] ? kobj_lookup+0x31e/0x400 [ 1001.419741] lo_open+0x19/0xb0 [ 1001.423200] ? loop_unregister_transfer+0x90/0x90 [ 1001.428116] __blkdev_get+0xa8c/0x1090 [ 1001.432005] ? lookup_fast+0x430/0xe30 [ 1001.436013] ? sb_min_blocksize+0x1d0/0x1d0 [ 1001.440460] ? fsnotify+0x974/0x11b0 [ 1001.444226] blkdev_get+0x88/0x890 [ 1001.447775] ? __blkdev_get+0x1090/0x1090 [ 1001.451903] ? lock_downgrade+0x740/0x740 [ 1001.456111] ? do_raw_spin_unlock+0x164/0x220 [ 1001.460688] ? _raw_spin_unlock+0x29/0x40 [ 1001.465008] blkdev_open+0x1cc/0x250 [ 1001.468729] ? security_file_open+0x82/0x190 [ 1001.473162] do_dentry_open+0x44b/0xec0 [ 1001.477359] ? blkdev_get_by_dev+0x70/0x70 [ 1001.481686] vfs_open+0x105/0x220 [ 1001.485438] path_openat+0x628/0x2970 [ 1001.489418] ? path_lookupat+0x780/0x780 [ 1001.493612] ? trace_hardirqs_on+0x10/0x10 [ 1001.497864] do_filp_open+0x179/0x3c0 [ 1001.501656] ? may_open_dev+0xe0/0xe0 [ 1001.505616] ? lock_downgrade+0x740/0x740 [ 1001.509790] ? do_raw_spin_unlock+0x164/0x220 [ 1001.514319] ? _raw_spin_unlock+0x29/0x40 [ 1001.518462] ? __alloc_fd+0x1be/0x490 [ 1001.522256] do_sys_open+0x296/0x410 [ 1001.526463] ? filp_open+0x60/0x60 [ 1001.529999] ? do_syscall_64+0x4c/0x640 [ 1001.534010] ? do_sys_open+0x410/0x410 [ 1001.537897] do_syscall_64+0x1d5/0x640 [ 1001.541765] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 1001.547101] RIP: 0033:0x7fcc39726840 [ 1001.550812] RSP: 002b:00007ffdb19a5018 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 1001.558639] RAX: ffffffffffffffda RBX: 0000562190231e60 RCX: 00007fcc39726840 [ 1001.565974] RDX: 000056218e28bfe3 RSI: 0000000000080000 RDI: 000056219022f660 [ 1001.573419] RBP: 0000000000000001 R08: 000056218e28b670 R09: 0000000000000110 [ 1001.580697] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 1001.588021] R13: 0000000000000000 R14: 000056219022c550 R15: 00000000ffffffff [ 1001.595564] INFO: task syz-executor048:8111 blocked for more than 140 seconds. [ 1001.602912] Not tainted 4.14.218-syzkaller #0 [ 1001.608218] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1001.616320] syz-executor048 D28912 8111 7980 0x00000004 [ 1001.621981] Call Trace: [ 1001.624607] __schedule+0x88b/0x1de0 [ 1001.628414] ? io_schedule_timeout+0x140/0x140 [ 1001.632977] ? lock_downgrade+0x740/0x740 [ 1001.637180] schedule+0x8d/0x1b0 [ 1001.640630] schedule_preempt_disabled+0xf/0x20 [ 1001.645511] __mutex_lock+0x669/0x1310 [ 1001.649419] ? blkdev_reread_part+0x1b/0x40 [ 1001.653768] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 1001.659223] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 1001.664413] ? __wake_up_common+0x5d0/0x5d0 [ 1001.668839] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 1001.673979] blkdev_reread_part+0x1b/0x40 [ 1001.678122] loop_set_status+0xeeb/0x12b0 [ 1001.682262] loop_set_status64+0x92/0xe0 [ 1001.686401] ? loop_set_status_old+0x200/0x200 [ 1001.691064] ? __mutex_lock+0x360/0x1310 [ 1001.695592] ? wait_for_completion_io+0x10/0x10 [ 1001.700271] ? set_blocksize+0x125/0x380 [ 1001.704402] lo_ioctl+0x587/0x1cd0 [ 1001.707954] ? loop_set_status64+0xe0/0xe0 [ 1001.712171] blkdev_ioctl+0x540/0x1830 [ 1001.716087] ? blkpg_ioctl+0x8d0/0x8d0 [ 1001.719979] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 1001.725432] ? debug_check_no_obj_freed+0x2c0/0x680 [ 1001.730449] block_ioctl+0xd9/0x120 [ 1001.734101] ? blkdev_fallocate+0x3a0/0x3a0 [ 1001.738423] do_vfs_ioctl+0x75a/0xff0 [ 1001.742211] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 1001.747729] ? ioctl_preallocate+0x1a0/0x1a0 [ 1001.752341] ? kmem_cache_free+0x23a/0x2b0 [ 1001.756609] ? putname+0xcd/0x110 [ 1001.760069] ? do_sys_open+0x208/0x410 [ 1001.764018] ? filp_open+0x60/0x60 [ 1001.767557] ? security_file_ioctl+0x83/0xb0 [ 1001.771964] SyS_ioctl+0x7f/0xb0 [ 1001.775361] ? do_vfs_ioctl+0xff0/0xff0 [ 1001.779333] do_syscall_64+0x1d5/0x640 [ 1001.783267] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 1001.788489] RIP: 0033:0x43fe67 [ 1001.791659] RSP: 002b:00007ffc0592c1a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 1001.799422] RAX: ffffffffffffffda RBX: 00007ffc0592c1d0 RCX: 000000000043fe67 [ 1001.806839] RDX: 00007ffc0592c2e0 RSI: 0000000000004c04 RDI: 0000000000000005 [ 1001.814170] RBP: 0000000000000005 R08: 00007ffc0592c040 R09: 00000000fbad8001 [ 1001.821809] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 [ 1001.829256] R13: 0000000001cbe2c0 R14: 00007ffc0592c2e0 R15: 00007ffc0592c420 [ 1001.836754] INFO: task syz-executor048:8113 blocked for more than 140 seconds. [ 1001.844181] Not tainted 4.14.218-syzkaller #0 [ 1001.849187] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1001.857395] syz-executor048 D28912 8113 7981 0x00000004 [ 1001.863030] Call Trace: [ 1001.865779] __schedule+0x88b/0x1de0 [ 1001.869505] ? io_schedule_timeout+0x140/0x140 [ 1001.874221] ? lock_downgrade+0x740/0x740 [ 1001.878462] schedule+0x8d/0x1b0 [ 1001.881896] schedule_preempt_disabled+0xf/0x20 [ 1001.886628] __mutex_lock+0x669/0x1310 [ 1001.890511] ? loop_control_ioctl+0x181/0x3f0 [ 1001.895413] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 1001.900964] ? loop_queue_work+0x1e80/0x1e80 [ 1001.905849] loop_control_ioctl+0x181/0x3f0 [ 1001.910493] ? loop_lookup+0x190/0x190 [ 1001.914448] ? vm_insert_page+0x7c0/0x7c0 [ 1001.918593] ? loop_lookup+0x190/0x190 [ 1001.923733] do_vfs_ioctl+0x75a/0xff0 [ 1001.927550] ? ioctl_preallocate+0x1a0/0x1a0 [ 1001.931948] ? lock_downgrade+0x740/0x740 [ 1001.936187] ? security_file_ioctl+0x83/0xb0 [ 1001.940595] SyS_ioctl+0x7f/0xb0 [ 1001.943989] ? do_vfs_ioctl+0xff0/0xff0 [ 1001.948132] do_syscall_64+0x1d5/0x640 [ 1001.952024] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 1001.957359] RIP: 0033:0x43ffb9 [ 1001.960551] RSP: 002b:00007ffc0592c408 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 1001.968475] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 000000000043ffb9 [ 1001.975828] RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 [ 1001.983299] RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d [ 1001.990693] R10: 000000000000000d R11: 0000000000000246 R12: 00000000000b7e8f [ 1001.998549] R13: 00007ffc0592c430 R14: 00007ffc0592c41c R15: 00007ffc0592c420 [ 1002.006171] INFO: task syz-executor048:8116 blocked for more than 140 seconds. [ 1002.013587] Not tainted 4.14.218-syzkaller #0 [ 1002.018607] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1002.026610] syz-executor048 D28328 8116 7984 0x00000004 [ 1002.032240] Call Trace: [ 1002.034868] __schedule+0x88b/0x1de0 [ 1002.038578] ? io_schedule_timeout+0x140/0x140 [ 1002.043298] ? lock_downgrade+0x740/0x740 [ 1002.047526] schedule+0x8d/0x1b0 [ 1002.050871] schedule_preempt_disabled+0xf/0x20 [ 1002.055672] __mutex_lock+0x669/0x1310 [ 1002.059559] ? loop_control_ioctl+0x67/0x3f0 [ 1002.064022] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 1002.069463] ? wake_up_q+0x82/0xd0 [ 1002.072986] ? __mutex_unlock_slowpath+0x261/0x770 [ 1002.077950] ? loop_add+0x2d2/0x830 [ 1002.081573] loop_control_ioctl+0x67/0x3f0 [ 1002.085952] ? loop_lookup+0x190/0x190 [ 1002.089923] ? vm_insert_page+0x7c0/0x7c0 [ 1002.094108] ? loop_lookup+0x190/0x190 [ 1002.097992] do_vfs_ioctl+0x75a/0xff0 [ 1002.101958] ? ioctl_preallocate+0x1a0/0x1a0 [ 1002.106402] ? lock_downgrade+0x740/0x740 [ 1002.110647] ? security_file_ioctl+0x83/0xb0 [ 1002.115380] SyS_ioctl+0x7f/0xb0 [ 1002.118740] ? do_vfs_ioctl+0xff0/0xff0 [ 1002.122697] do_syscall_64+0x1d5/0x640 [ 1002.126630] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 1002.131819] RIP: 0033:0x43ffb9 [ 1002.135045] RSP: 002b:00007ffc0592c408 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 1002.143017] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 000000000043ffb9 [ 1002.150355] RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 [ 1002.157898] RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d [ 1002.165208] R10: 000000000000000d R11: 0000000000000246 R12: 00000000000b7f00 [ 1002.172483] R13: 00007ffc0592c430 R14: 00007ffc0592c41c R15: 00007ffc0592c420 [ 1002.179817] INFO: task syz-executor048:8118 blocked for more than 140 seconds. [ 1002.187222] Not tainted 4.14.218-syzkaller #0 [ 1002.192236] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1002.200256] syz-executor048 D28912 8118 7982 0x00000004 [ 1002.205973] Call Trace: [ 1002.208558] __schedule+0x88b/0x1de0 [ 1002.212254] ? io_schedule_timeout+0x140/0x140 [ 1002.216933] ? lock_downgrade+0x740/0x740 [ 1002.221095] schedule+0x8d/0x1b0 [ 1002.224498] schedule_preempt_disabled+0xf/0x20 [ 1002.229174] __mutex_lock+0x669/0x1310 [ 1002.233046] ? loop_control_ioctl+0x67/0x3f0 [ 1002.237491] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 1002.242937] ? __lock_acquire+0x5fc/0x3f20 [ 1002.248528] ? do_wp_page+0x24d/0x1db0 [ 1002.252424] ? finish_mkwrite_fault+0x5e0/0x5e0 [ 1002.257143] loop_control_ioctl+0x67/0x3f0 [ 1002.261461] ? loop_lookup+0x190/0x190 [ 1002.265487] ? vm_insert_page+0x7c0/0x7c0 [ 1002.269646] ? loop_lookup+0x190/0x190 [ 1002.273566] do_vfs_ioctl+0x75a/0xff0 [ 1002.277363] ? ioctl_preallocate+0x1a0/0x1a0 [ 1002.281753] ? lock_downgrade+0x740/0x740 [ 1002.286043] ? security_file_ioctl+0x83/0xb0 [ 1002.290456] SyS_ioctl+0x7f/0xb0 [ 1002.293855] ? do_vfs_ioctl+0xff0/0xff0 [ 1002.297824] do_syscall_64+0x1d5/0x640 [ 1002.301694] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 1002.306915] RIP: 0033:0x43ffb9 [ 1002.310117] RSP: 002b:00007ffc0592c408 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 1002.318112] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 000000000043ffb9 [ 1002.325790] RDX: 0000000000000000 RSI: 0000000000004c82 RDI: 0000000000000003 [ 1002.333457] RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d [ 1002.340722] R10: 00007ffc0592be80 R11: 0000000000000246 R12: 00000000000b7f19 [ 1002.348198] R13: 00007ffc0592c430 R14: 00007ffc0592c41c R15: 00007ffc0592c420 [ 1002.355556] INFO: task syz-executor048:8123 blocked for more than 140 seconds. [ 1002.363453] Not tainted 4.14.218-syzkaller #0 [ 1002.368464] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1002.376640] syz-executor048 D28912 8123 7985 0x00000004 [ 1002.382268] Call Trace: [ 1002.384890] __schedule+0x88b/0x1de0 [ 1002.388611] ? wp_page_copy+0xc31/0x25c0 [ 1002.392659] ? io_schedule_timeout+0x140/0x140 [ 1002.397282] ? lock_downgrade+0x740/0x740 [ 1002.401517] schedule+0x8d/0x1b0 [ 1002.404929] schedule_preempt_disabled+0xf/0x20 [ 1002.409852] __mutex_lock+0x669/0x1310 [ 1002.414057] ? loop_control_ioctl+0x67/0x3f0 [ 1002.418576] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 1002.424424] ? __lock_acquire+0x5fc/0x3f20 [ 1002.428880] ? do_wp_page+0x24d/0x1db0 [ 1002.432769] ? finish_mkwrite_fault+0x5e0/0x5e0 [ 1002.437773] loop_control_ioctl+0x67/0x3f0 [ 1002.442002] ? loop_lookup+0x190/0x190 [ 1002.445960] ? vm_insert_page+0x7c0/0x7c0 [ 1002.450337] ? loop_lookup+0x190/0x190 [ 1002.454409] do_vfs_ioctl+0x75a/0xff0 [ 1002.458500] ? ioctl_preallocate+0x1a0/0x1a0 [ 1002.462905] ? lock_downgrade+0x740/0x740 [ 1002.467380] ? security_file_ioctl+0x83/0xb0 [ 1002.471813] SyS_ioctl+0x7f/0xb0 [ 1002.475232] ? do_vfs_ioctl+0xff0/0xff0 [ 1002.479210] do_syscall_64+0x1d5/0x640 [ 1002.483235] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 1002.488541] RIP: 0033:0x43ffb9 [ 1002.491711] RSP: 002b:00007ffc0592c408 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 1002.499456] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 000000000043ffb9 [ 1002.507039] RDX: 0000000000000000 RSI: 0000000000004c82 RDI: 0000000000000003 [ 1002.514385] RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d [ 1002.521860] R10: 00007ffc0592be80 R11: 0000000000000246 R12: 00000000000b7f19 [ 1002.529408] R13: 00007ffc0592c430 R14: 00007ffc0592c41c R15: 00007ffc0592c420 [ 1002.536883] INFO: task syz-executor048:8125 blocked for more than 140 seconds. [ 1002.544380] Not tainted 4.14.218-syzkaller #0 [ 1002.549650] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1002.557738] syz-executor048 D28912 8125 7983 0x00000004 [ 1002.563409] Call Trace: [ 1002.566009] __schedule+0x88b/0x1de0 [ 1002.569809] ? wp_page_copy+0xc31/0x25c0 [ 1002.574021] ? io_schedule_timeout+0x140/0x140 [ 1002.578616] ? lock_downgrade+0x740/0x740 [ 1002.583670] schedule+0x8d/0x1b0 [ 1002.587239] schedule_preempt_disabled+0xf/0x20 [ 1002.591898] __mutex_lock+0x669/0x1310 [ 1002.595837] ? loop_control_ioctl+0x67/0x3f0 [ 1002.600272] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 1002.606100] ? __lock_acquire+0x5fc/0x3f20 [ 1002.610337] ? do_wp_page+0x24d/0x1db0 [ 1002.614278] ? finish_mkwrite_fault+0x5e0/0x5e0 [ 1002.619066] loop_control_ioctl+0x67/0x3f0 [ 1002.623605] ? loop_lookup+0x190/0x190 [ 1002.627847] ? vm_insert_page+0x7c0/0x7c0 [ 1002.632065] ? loop_lookup+0x190/0x190 [ 1002.636169] do_vfs_ioctl+0x75a/0xff0 [ 1002.640149] ? ioctl_preallocate+0x1a0/0x1a0 [ 1002.644609] ? lock_downgrade+0x740/0x740 [ 1002.648942] ? security_file_ioctl+0x83/0xb0 [ 1002.653388] SyS_ioctl+0x7f/0xb0 [ 1002.657190] ? do_vfs_ioctl+0xff0/0xff0 [ 1002.661581] do_syscall_64+0x1d5/0x640 [ 1002.665508] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 1002.670694] RIP: 0033:0x43ffb9 [ 1002.673933] RSP: 002b:00007ffc0592c408 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 1002.681650] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 000000000043ffb9 [ 1002.688982] RDX: 0000000000000000 RSI: 0000000000004c82 RDI: 0000000000000003 [ 1002.696301] RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d [ 1002.703697] R10: 00007ffc0592be80 R11: 0000000000000246 R12: 00000000000b7f1b [ 1002.710966] R13: 00007ffc0592c430 R14: 00007ffc0592c41c R15: 00007ffc0592c420 [ 1002.718310] [ 1002.718310] Showing all locks held in the system: [ 1002.724865] 1 lock held by khungtaskd/1527: [ 1002.729461] #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a [ 1002.738584] 2 locks held by systemd-udevd/8090: [ 1002.743324] #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 [ 1002.752005] #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 [ 1002.760146] 2 locks held by syz-executor048/8111: [ 1002.765410] #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1cd0 [ 1002.774243] #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 [ 1002.783249] 2 locks held by syz-executor048/8113: [ 1002.788071] #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 [ 1002.797287] #1: (&lo->lo_ctl_mutex){+.+.}, at: [] loop_control_ioctl+0x181/0x3f0 [ 1002.806622] 1 lock held by syz-executor048/8116: [ 1002.811363] #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 [ 1002.820616] 1 lock held by syz-executor048/8118: [ 1002.825424] #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 [ 1002.834631] 1 lock held by syz-executor048/8123: [ 1002.839375] #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 [ 1002.848618] 1 lock held by syz-executor048/8125: [ 1002.853487] #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 [ 1002.862696] [ 1002.864374] ============================================= [ 1002.864374] [ 1002.871528] NMI backtrace for cpu 0 [ 1002.871538] CPU: 0 PID: 1527 Comm: khungtaskd Not tainted 4.14.218-syzkaller #0 [ 1002.871542] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 1002.871545] Call Trace: [ 1002.871560] dump_stack+0x1b2/0x281 [ 1002.871571] nmi_cpu_backtrace.cold+0x57/0x93 [ 1002.871580] ? irq_force_complete_move+0x350/0x350 [ 1002.871589] nmi_trigger_cpumask_backtrace+0x13a/0x180 [ 1002.871598] watchdog+0x5b9/0xb40 [ 1002.871607] ? hungtask_pm_notify+0x50/0x50 [ 1002.871616] kthread+0x30d/0x420 [ 1002.871623] ? kthread_create_on_node+0xd0/0xd0 [ 1002.871632] ret_from_fork+0x24/0x30 [ 1002.871647] Sending NMI from CPU 0 to CPUs 1: [ 1002.938849] NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff8720d24e [ 1002.946566] Kernel panic - not syncing: hung_task: blocked tasks [ 1002.952707] CPU: 1 PID: 1527 Comm: khungtaskd Not tainted 4.14.218-syzkaller #0 [ 1002.960267] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 1002.969616] Call Trace: [ 1002.972189] dump_stack+0x1b2/0x281 [ 1002.975798] panic+0x1f9/0x42d [ 1002.978969] ? add_taint.cold+0x16/0x16 [ 1002.982923] watchdog+0x5ca/0xb40 [ 1002.986356] ? hungtask_pm_notify+0x50/0x50 [ 1002.990671] kthread+0x30d/0x420 [ 1002.994027] ? kthread_create_on_node+0xd0/0xd0 [ 1002.998717] ret_from_fork+0x24/0x30 [ 1003.003697] Kernel Offset: disabled [ 1003.007363] Rebooting in 86400 seconds..