[ 57.979314][ T26] audit: type=1800 audit(1572197176.849:25): pid=8689 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 57.999518][ T26] audit: type=1800 audit(1572197176.859:26): pid=8689 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 58.062484][ T26] audit: type=1800 audit(1572197176.859:27): pid=8689 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [ 58.374234][ T8757] sshd (8757) used greatest stack depth: 22888 bytes left [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.15.204' (ECDSA) to the list of known hosts. syzkaller login: [ 238.011153][ T1077] INFO: task khugepaged:1084 blocked for more than 143 seconds. [ 238.019059][ T1077] Not tainted 5.4.0-rc4-next-20191025 #0 [ 238.025299][ T1077] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 238.034038][ T1077] khugepaged D27840 1084 2 0x80004000 [ 238.040408][ T1077] Call Trace: [ 238.043814][ T1077] __schedule+0x94a/0x1e70 [ 238.048334][ T1077] ? __sched_text_start+0x8/0x8 [ 238.053289][ T1077] ? blk_insert_cloned_request+0x530/0x530 [ 238.059275][ T1077] ? _raw_spin_unlock_irq+0x23/0x80 [ 238.064542][ T1077] ? __lock_page+0x3d9/0xab0 [ 238.069313][ T1077] ? _raw_spin_unlock_irq+0x23/0x80 [ 238.074608][ T1077] schedule+0xdc/0x2b0 [ 238.078699][ T1077] io_schedule+0x1c/0x70 [ 238.082999][ T1077] __lock_page+0x422/0xab0 [ 238.087433][ T1077] ? wait_on_page_bit+0xa60/0xa60 [ 238.092648][ T1077] ? page_cache_next_miss+0x340/0x340 [ 238.098036][ T1077] ? ___might_sleep+0x163/0x2c0 [ 238.104179][ T1077] ? __might_sleep+0x95/0x190 [ 238.108889][ T1077] mpage_prepare_extent_to_map+0xb3f/0xf90 [ 238.114834][ T1077] ? mpage_process_page_bufs+0x780/0x780 [ 238.120482][ T1077] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 238.127325][ T1077] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 238.133682][ T1077] ext4_writepages+0xb6a/0x2e70 [ 238.138622][ T1077] ? __this_cpu_preempt_check+0x2c/0x190 [ 238.144336][ T1077] ? ext4_mark_inode_dirty+0x9b0/0x9b0 [ 238.149805][ T1077] ? 0xffffffff81000000 [ 238.154112][ T1077] ? mark_lock+0xc2/0x1220 [ 238.158574][ T1077] ? prep_new_page+0x19f/0x200 [ 238.163399][ T1077] ? wbc_attach_and_unlock_inode+0x515/0x920 [ 238.169655][ T1077] ? find_held_lock+0x35/0x130 [ 238.174523][ T1077] ? wbc_attach_and_unlock_inode+0x515/0x920 [ 238.180519][ T1077] ? ext4_mark_inode_dirty+0x9b0/0x9b0 [ 238.186129][ T1077] do_writepages+0xfa/0x2a0 [ 238.190689][ T1077] ? do_writepages+0xfa/0x2a0 [ 238.195470][ T1077] ? lock_downgrade+0x920/0x920 [ 238.200390][ T1077] ? page_writeback_cpu_online+0x20/0x20 [ 238.206108][ T1077] ? __kasan_check_read+0x11/0x20 [ 238.211207][ T1077] ? do_raw_spin_unlock+0x57/0x270 [ 238.216345][ T1077] ? _raw_spin_unlock+0x28/0x40 [ 238.221252][ T1077] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 238.227500][ T1077] ? wbc_attach_and_unlock_inode+0x5bf/0x920 [ 238.233559][ T1077] __filemap_fdatawrite_range+0x2bc/0x3b0 [ 238.239306][ T1077] ? delete_from_page_cache_batch+0xfe0/0xfe0 [ 238.245451][ T1077] ? lockdep_hardirqs_on+0x421/0x5e0 [ 238.250758][ T1077] filemap_flush+0x24/0x30 [ 238.255974][ T1077] collapse_file+0x36b1/0x41a0 [ 238.260758][ T1077] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 238.267005][ T1077] ? khugepaged+0x21d0/0x4360 [ 238.271778][ T1077] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 238.279897][ T1077] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 238.285812][ T1077] ? khugepaged_find_target_node+0x142/0x180 [ 238.291851][ T1077] khugepaged+0x2da9/0x4360 [ 238.296354][ T1077] ? __kasan_check_read+0x11/0x20 [ 238.301558][ T1077] ? __lock_acquire+0x16f2/0x4a00 [ 238.306624][ T1077] ? _raw_spin_unlock_irq+0x23/0x80 [ 238.311899][ T1077] ? finish_task_switch+0x147/0x750 [ 238.317104][ T1077] ? _raw_spin_unlock_irq+0x23/0x80 [ 238.322388][ T1077] ? lockdep_hardirqs_on+0x421/0x5e0 [ 238.327717][ T1077] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 238.333657][ T1077] ? lock_downgrade+0x920/0x920 [ 238.338523][ T1077] ? finish_wait+0x260/0x260 [ 238.343373][ T1077] ? lockdep_hardirqs_on+0x421/0x5e0 [ 238.348665][ T1077] ? trace_hardirqs_on+0x67/0x240 [ 238.353789][ T1077] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 238.360031][ T1077] ? __kthread_parkme+0x108/0x1c0 [ 238.365127][ T1077] ? __kasan_check_read+0x11/0x20 [ 238.370163][ T1077] kthread+0x361/0x430 [ 238.374303][ T1077] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 238.380025][ T1077] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 238.386548][ T1077] ret_from_fork+0x24/0x30 [ 238.391244][ T1077] [ 238.391244][ T1077] Showing all locks held in the system: [ 238.398982][ T1077] 4 locks held by kworker/u4:1/21: [ 238.404134][ T1077] #0: ffff8880a79d4928 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740 [ 238.414383][ T1077] #1: ffff8880a9a07dc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 [ 238.425735][ T1077] #2: ffff8882158160d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110 [ 238.435285][ T1077] #3: ffff888215818990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 [ 238.445357][ T1077] 1 lock held by khungtaskd/1077: [ 238.450386][ T1077] #0: ffffffff88faba80 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 [ 238.459769][ T1077] 1 lock held by khugepaged/1084: [ 238.464974][ T1077] #0: ffff888215818990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 [ 238.474898][ T1077] 1 lock held by rsyslogd/8727: [ 238.479744][ T1077] #0: ffff8880996093e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 [ 238.488513][ T1077] 2 locks held by getty/8817: [ 238.493231][ T1077] #0: ffff88808f466090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 238.502575][ T1077] #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 238.513015][ T1077] 2 locks held by getty/8818: [ 238.517677][ T1077] #0: ffff8880a098b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 238.526683][ T1077] #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 238.536435][ T1077] 2 locks held by getty/8819: [ 238.541150][ T1077] #0: ffff8880a49c8090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 238.550227][ T1077] #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 238.559876][ T1077] 2 locks held by getty/8820: [ 238.564720][ T1077] #0: ffff888091e50090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 238.573760][ T1077] #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 238.583511][ T1077] 2 locks held by getty/8821: [ 238.588173][ T1077] #0: ffff88809c946090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 238.597831][ T1077] #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 238.607742][ T1077] 2 locks held by getty/8822: [ 238.612482][ T1077] #0: ffff8880a94e8090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 238.621503][ T1077] #1: ffffc90005f1d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 238.631148][ T1077] 2 locks held by getty/8823: [ 238.635829][ T1077] #0: ffff8880a450a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 238.645580][ T1077] #1: ffffc90005ef12e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 238.655372][ T1077] 1 lock held by syz-execprog/8843: [ 238.660663][ T1077] #0: ffff88809090f428 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7e/0xb2 [ 238.669922][ T1077] [ 238.672308][ T1077] ============================================= [ 238.672308][ T1077] [ 238.680732][ T1077] NMI backtrace for cpu 0 [ 238.685108][ T1077] CPU: 0 PID: 1077 Comm: khungtaskd Not tainted 5.4.0-rc4-next-20191025 #0 [ 238.693695][ T1077] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 238.703752][ T1077] Call Trace: [ 238.707039][ T1077] dump_stack+0x172/0x1f0 [ 238.711370][ T1077] nmi_cpu_backtrace.cold+0x70/0xb2 [ 238.716996][ T1077] ? vprintk_func+0x86/0x189 [ 238.721587][ T1077] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 238.727228][ T1077] nmi_trigger_cpumask_backtrace+0x23b/0x28b [ 238.733395][ T1077] arch_trigger_cpumask_backtrace+0x14/0x20 [ 238.739285][ T1077] watchdog+0xc8f/0x1350 [ 238.743638][ T1077] kthread+0x361/0x430 [ 238.747710][ T1077] ? reset_hung_task_detector+0x30/0x30 [ 238.753258][ T1077] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 238.758981][ T1077] ret_from_fork+0x24/0x30 [ 238.763502][ T1077] Sending NMI from CPU 0 to CPUs 1: [ 238.768756][ C1] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 [ 238.769710][ T1077] Kernel panic - not syncing: hung_task: blocked tasks [ 238.783835][ T1077] CPU: 0 PID: 1077 Comm: khungtaskd Not tainted 5.4.0-rc4-next-20191025 #0 [ 238.792409][ T1077] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 238.802450][ T1077] Call Trace: [ 238.805767][ T1077] dump_stack+0x172/0x1f0 [ 238.810098][ T1077] panic+0x2e3/0x75c [ 238.814007][ T1077] ? add_taint.cold+0x16/0x16 [ 238.818691][ T1077] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 238.824407][ T1077] ? printk_safe_flush+0xf2/0x140 [ 238.829482][ T1077] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 238.835733][ T1077] ? nmi_trigger_cpumask_backtrace+0x224/0x28b [ 238.841951][ T1077] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 238.848121][ T1077] watchdog+0xca0/0x1350 [ 238.852613][ T1077] kthread+0x361/0x430 [ 238.856725][ T1077] ? reset_hung_task_detector+0x30/0x30 [ 238.862266][ T1077] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 238.867986][ T1077] ret_from_fork+0x24/0x30 [ 238.874024][ T1077] Kernel Offset: disabled [ 238.878362][ T1077] Rebooting in 86400 seconds..