[ OK ] Reached target Login Prompts. [ 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 syzkaller login: [ 38.596050][ T6810] bash (6810) used greatest stack depth: 24592 bytes left Warning: Permanently added '10.128.0.149' (ECDSA) to the list of known hosts. [ 458.542069][ T6846] NILFS (loop0): broken superblock, retrying with spare superblock (blocksize = 1024) [ 458.553195][ T6846] NILFS (loop0): broken superblock, retrying with spare superblock (blocksize = 2048) [ 458.566479][ T6846] NILFS (loop0): mounting unchecked fs [ 458.582166][ T6846] NILFS (loop0): recovery complete [ 458.601774][ T6850] NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds [ 616.226949][ T1178] INFO: task syz-executor931:6845 blocked for more than 143 seconds. [ 616.235146][ T1178] Not tainted 5.9.0-rc8-syzkaller #0 [ 616.241191][ T1178] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 616.249942][ T1178] task:syz-executor931 state:D stack:28128 pid: 6845 ppid: 6839 flags:0x00004000 [ 616.259244][ T1178] Call Trace: [ 616.262638][ T1178] __schedule+0x9b9/0xd20 [ 616.267274][ T1178] ? schedule+0x188/0x220 [ 616.271666][ T1178] ? wb_wait_for_completion+0x105/0x200 [ 616.277418][ T1178] ? init_wait_entry+0xd0/0xd0 [ 616.282184][ T1178] ? sync_inodes_sb+0x1ec/0x9b0 [ 616.288128][ T1178] ? memset+0x1f/0x40 [ 616.292142][ T1178] ? I_BDEV+0x9/0x20 [ 616.296067][ T1178] ? __filemap_fdatawrite_range+0x228/0x350 [ 616.302068][ T1178] ? sync_filesystem+0x148/0x200 [ 616.307156][ T1178] ? generic_shutdown_super+0x6b/0x2a0 [ 616.312600][ T1178] ? kill_block_super+0x79/0xd0 [ 616.317522][ T1178] ? deactivate_locked_super+0xa7/0xf0 [ 616.323013][ T1178] ? cleanup_mnt+0x432/0x4e0 [ 616.327826][ T1178] ? task_work_run+0x137/0x1c0 [ 616.332637][ T1178] ? exit_to_user_mode_prepare+0x11a/0x1e0 [ 616.338555][ T1178] ? syscall_exit_to_user_mode+0x82/0x1d0 [ 616.344279][ T1178] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 616.350436][ T1178] [ 616.350436][ T1178] Showing all locks held in the system: [ 616.358332][ T1178] 2 locks held by kworker/u4:0/7: [ 616.363338][ T1178] #0: ffff88821ae2d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 [ 616.373963][ T1178] #1: ffffc90000cdfd80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 [ 616.385827][ T1178] 1 lock held by khungtaskd/1178: [ 616.390930][ T1178] #0: ffffffff896fe550 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 [ 616.400511][ T1178] 1 lock held by in:imklog/6529: [ 616.405453][ T1178] #0: ffff8880a9243630 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x253/0x2f0 [ 616.414855][ T1178] 2 locks held by syz-executor931/6845: [ 616.421023][ T1178] #0: ffff8880939060e0 (&type->s_umount_key#49){+.+.}-{3:3}, at: deactivate_super+0x96/0xd0 [ 616.431275][ T1178] #1: ffff8880a12aa730 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1d3/0x9b0 [ 616.441476][ T1178] [ 616.443795][ T1178] ============================================= [ 616.443795][ T1178] [ 616.452271][ T1178] NMI backtrace for cpu 0 [ 616.456598][ T1178] CPU: 0 PID: 1178 Comm: khungtaskd Not tainted 5.9.0-rc8-syzkaller #0 [ 616.464808][ T1178] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 616.474847][ T1178] Call Trace: [ 616.478239][ T1178] dump_stack+0x1d6/0x29e [ 616.482552][ T1178] nmi_cpu_backtrace+0x9f/0x180 [ 616.487444][ T1178] ? arch_trigger_cpumask_backtrace+0x10/0x10 [ 616.493499][ T1178] nmi_trigger_cpumask_backtrace+0x16a/0x280 [ 616.499523][ T1178] watchdog+0xd65/0xdb0 [ 616.503733][ T1178] kthread+0x37e/0x3a0 [ 616.507790][ T1178] ? hungtask_pm_notify+0x50/0x50 [ 616.512800][ T1178] ? kthread_blkcg+0xd0/0xd0 [ 616.517442][ T1178] ret_from_fork+0x1f/0x30 [ 616.522058][ T1178] Sending NMI from CPU 0 to CPUs 1: [ 616.527828][ C1] NMI backtrace for cpu 1 [ 616.527833][ C1] CPU: 1 PID: 6850 Comm: segctord Not tainted 5.9.0-rc8-syzkaller #0 [ 616.527837][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 616.527840][ C1] RIP: 0010:pagecache_get_page+0x123/0xe50 [ 616.527847][ C1] Code: 01 31 ff e8 9f 76 dd ff 48 89 e8 48 83 e0 01 0f 85 d2 01 00 00 48 89 df be 08 00 00 00 e8 b5 26 1d 00 31 f6 f0 48 0f ba 2b 00 <0f> 92 c3 40 0f 92 c6 31 ff e8 8f 74 dd ff 84 db 0f 85 8c 00 00 00 [ 616.527850][ C1] RSP: 0018:ffffc90005327730 EFLAGS: 00000246 [ 616.527856][ C1] RAX: 0000000000000001 RBX: ffffea0002573240 RCX: ffffffff81978c1b [ 616.527860][ C1] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffea0002573240 [ 616.527864][ C1] RBP: ffffea0002349008 R08: dffffc0000000000 R09: fffff940004ae649 [ 616.527867][ C1] R10: fffff940004ae649 R11: 0000000000000000 R12: 1ffffd40004ae649 [ 616.527871][ C1] R13: ffffea0002573248 R14: dffffc0000000000 R15: 0000000000000007 [ 616.527875][ C1] FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 [ 616.527878][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 616.527881][ C1] CR2: 00007f4286aaa000 CR3: 0000000093ca3000 CR4: 00000000001506e0 [ 616.527885][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 616.527888][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 616.527891][ C1] Call Trace: [ 616.527893][ C1] nilfs_grab_buffer+0x87/0x680 [ 616.527896][ C1] ? lock_is_held_type+0xb3/0xe0 [ 616.527899][ C1] nilfs_mdt_submit_block+0x81/0x6b0 [ 616.527901][ C1] ? lock_acquire+0x148/0x720 [ 616.527904][ C1] nilfs_mdt_read_block+0x46/0x3e0 [ 616.527907][ C1] nilfs_mdt_get_block+0x3f/0xa0 [ 616.527910][ C1] nilfs_sufile_set_segment_usage+0xdb/0x520 [ 616.527913][ C1] ? grow_dev_page+0x57d/0x690 [ 616.527916][ C1] nilfs_segctor_abort_construction+0x786/0xde0 [ 616.527919][ C1] nilfs_segctor_do_construct+0x714b/0x78a0 [ 616.527921][ C1] ? lock_is_held_type+0xb3/0xe0 [ 616.527924][ C1] nilfs_segctor_construct+0x14b/0x940 [ 616.527927][ C1] ? rcu_read_lock_sched_held+0x2f/0xa0 [ 616.527930][ C1] nilfs_segctor_thread+0x457/0x1040 [ 616.527932][ C1] kthread+0x37e/0x3a0 [ 616.527935][ C1] ? nilfs_construction_timeout+0x40/0x40 [ 616.527938][ C1] ? kthread_blkcg+0xd0/0xd0 [ 616.527940][ C1] ret_from_fork+0x1f/0x30 [ 616.528765][ T1178] Kernel panic - not syncing: hung_task: blocked tasks [ 616.763133][ T1178] CPU: 0 PID: 1178 Comm: khungtaskd Not tainted 5.9.0-rc8-syzkaller #0 [ 616.771344][ T1178] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 616.781375][ T1178] Call Trace: [ 616.784645][ T1178] dump_stack+0x1d6/0x29e [ 616.789041][ T1178] panic+0x2c0/0x800 [ 616.792940][ T1178] ? nmi_trigger_cpumask_backtrace+0x206/0x280 [ 616.799074][ T1178] watchdog+0xda5/0xdb0 [ 616.803208][ T1178] kthread+0x37e/0x3a0 [ 616.807248][ T1178] ? hungtask_pm_notify+0x50/0x50 [ 616.812261][ T1178] ? kthread_blkcg+0xd0/0xd0 [ 616.816832][ T1178] ret_from_fork+0x1f/0x30 [ 616.822482][ T1178] Kernel Offset: disabled [ 616.826801][ T1178] Rebooting in 86400 seconds..