[ 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 '10.128.10.9' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 857.990881] INFO: task syz-executor714:7983 blocked for more than 140 seconds. [ 857.998472] Not tainted 4.14.237-syzkaller #0 [ 858.004553] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 858.012602] syz-executor714 D27840 7983 7981 0x00000004 [ 858.018531] Call Trace: [ 858.021368] __schedule+0x88b/0x1de0 [ 858.025100] ? lock_acquire+0x170/0x3f0 [ 858.029061] ? io_schedule_timeout+0x140/0x140 [ 858.033694] ? _raw_spin_unlock+0x29/0x40 [ 858.037842] ? fuse_writepage_locked+0xe80/0xe80 [ 858.042637] schedule+0x8d/0x1b0 [ 858.046001] fuse_wait_on_page_writeback.isra.0+0xdc/0x120 [ 858.051869] ? fuse_do_ioctl+0x1570/0x1570 [ 858.056113] ? end_page_writeback+0xe3/0x1c0 [ 858.060504] ? wait_woken+0x230/0x230 [ 858.064382] fuse_launder_page+0xa2/0xd0 [ 858.068456] invalidate_inode_pages2_range+0x547/0xc00 [ 858.073810] ? clear_shadow_entry+0x160/0x160 [ 858.078299] ? fuse_range_is_writeback+0x1f0/0x1f0 [ 858.083264] ? fuse_file_alloc+0x1ca/0x260 [ 858.087496] ? _raw_spin_unlock+0x29/0x40 [ 858.091694] ? fuse_do_open+0x18e/0x460 [ 858.095667] fuse_finish_open+0x262/0x500 [ 858.099794] fuse_open_common+0x1fc/0x250 [ 858.103975] do_dentry_open+0x44b/0xec0 [ 858.108032] ? fuse_open_common+0x250/0x250 [ 858.112396] ? __inode_permission+0xcd/0x2f0 [ 858.116986] vfs_open+0x105/0x220 [ 858.120449] path_openat+0x628/0x2970 [ 858.124289] ? path_lookupat+0x780/0x780 [ 858.128348] ? trace_hardirqs_on+0x10/0x10 [ 858.132628] do_filp_open+0x179/0x3c0 [ 858.136464] ? may_open_dev+0xe0/0xe0 [ 858.140264] ? lock_downgrade+0x740/0x740 [ 858.144443] ? do_raw_spin_unlock+0x164/0x220 [ 858.148934] ? _raw_spin_unlock+0x29/0x40 [ 858.153571] ? __alloc_fd+0x1be/0x490 [ 858.157380] do_sys_open+0x296/0x410 [ 858.161137] ? filp_open+0x60/0x60 [ 858.164906] ? do_syscall_64+0x4c/0x640 [ 858.168912] ? do_sys_open+0x410/0x410 [ 858.172864] do_syscall_64+0x1d5/0x640 [ 858.176750] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 858.182141] RIP: 0033:0x446399 [ 858.185321] RSP: 002b:00007fe6a31ee2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 858.193166] RAX: ffffffffffffffda RBX: 00000000004d34e0 RCX: 0000000000446399 [ 858.200622] RDX: 0000000000000000 RSI: 0000000000080380 RDI: 0000000020000100 [ 858.207921] RBP: 00000000004a3164 R08: 0000000000000000 R09: 0000000000000000 [ 858.215396] R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e [ 858.222866] R13: 000000000049f158 R14: 00000000004a1160 R15: 00000000004d34e8 [ 858.230248] [ 858.230248] Showing all locks held in the system: [ 858.236833] 1 lock held by khungtaskd/1533: [ 858.241329] #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a [ 858.251527] 2 locks held by syz-executor714/7983: [ 858.256453] #0: (sb_writers#10){.+.+}, at: [] mnt_want_write+0x3a/0xb0 [ 858.264932] #1: (&sb->s_type->i_mutex_key#17){+.+.}, at: [] fuse_open_common+0x177/0x250 [ 858.275384] [ 858.277091] ============================================= [ 858.277091] [ 858.285882] NMI backtrace for cpu 1 [ 858.289560] CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.237-syzkaller #0 [ 858.296997] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 858.306340] Call Trace: [ 858.308927] dump_stack+0x1b2/0x281 [ 858.312536] nmi_cpu_backtrace.cold+0x57/0x93 [ 858.317034] ? irq_force_complete_move+0x350/0x350 [ 858.321946] nmi_trigger_cpumask_backtrace+0x13a/0x180 [ 858.327203] watchdog+0x5b9/0xb40 [ 858.330794] ? hungtask_pm_notify+0x50/0x50 [ 858.335115] kthread+0x30d/0x420 [ 858.338463] ? kthread_create_on_node+0xd0/0xd0 [ 858.343813] ret_from_fork+0x24/0x30 [ 858.347636] Sending NMI from CPU 1 to CPUs 0: [ 858.352241] NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff8722cade [ 858.353195] Kernel panic - not syncing: hung_task: blocked tasks [ 858.365833] CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.237-syzkaller #0 [ 858.373369] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 858.384073] Call Trace: [ 858.387103] dump_stack+0x1b2/0x281 [ 858.391171] panic+0x1f9/0x42d [ 858.394366] ? add_taint.cold+0x16/0x16 [ 858.398778] watchdog+0x5ca/0xb40 [ 858.402408] ? hungtask_pm_notify+0x50/0x50 [ 858.406715] kthread+0x30d/0x420 [ 858.410074] ? kthread_create_on_node+0xd0/0xd0 [ 858.414723] ret_from_fork+0x24/0x30 [ 858.419388] Kernel Offset: disabled [ 858.423203] Rebooting in 86400 seconds..