[ 55.217395][ T26] audit: type=1800 audit(1572213663.563:25): pid=8633 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 55.242623][ T26] audit: type=1800 audit(1572213663.563:26): pid=8633 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 55.310856][ T26] audit: type=1800 audit(1572213663.563:27): pid=8633 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 55.823629][ T8699] sshd (8699) used greatest stack depth: 22888 bytes left [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.1.34' (ECDSA) to the list of known hosts. syzkaller login: [ 214.521815][ T1076] INFO: task khugepaged:1084 blocked for more than 143 seconds. [ 214.529731][ T1076] Not tainted 5.4.0-rc4-next-20191025 #0 [ 214.535942][ T1076] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 214.544674][ T1076] khugepaged D27848 1084 2 0x80004000 [ 214.551010][ T1076] Call Trace: [ 214.554343][ T1076] __schedule+0x94a/0x1e70 [ 214.558779][ T1076] ? __sched_text_start+0x8/0x8 [ 214.564397][ T1076] ? blk_insert_cloned_request+0x530/0x530 [ 214.570228][ T1076] ? _raw_spin_unlock_irq+0x23/0x80 [ 214.575500][ T1076] ? __lock_page+0x3d9/0xab0 [ 214.580088][ T1076] ? _raw_spin_unlock_irq+0x23/0x80 [ 214.585378][ T1076] schedule+0xdc/0x2b0 [ 214.589691][ T1076] io_schedule+0x1c/0x70 [ 214.594787][ T1076] __lock_page+0x422/0xab0 [ 214.599311][ T1076] ? wait_on_page_bit+0xa60/0xa60 [ 214.604750][ T1076] ? page_cache_next_miss+0x340/0x340 [ 214.611924][ T1076] ? ___might_sleep+0x163/0x2c0 [ 214.616788][ T1076] ? __might_sleep+0x95/0x190 [ 214.621467][ T1076] mpage_prepare_extent_to_map+0xb3f/0xf90 [ 214.627372][ T1076] ? mpage_process_page_bufs+0x780/0x780 [ 214.633093][ T1076] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 214.639075][ T1076] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 214.645446][ T1076] ext4_writepages+0xb6a/0x2e70 [ 214.650320][ T1076] ? __this_cpu_preempt_check+0x2c/0x190 [ 214.656034][ T1076] ? ext4_mark_inode_dirty+0x9b0/0x9b0 [ 214.661506][ T1076] ? 0xffffffff81000000 [ 214.665745][ T1076] ? mark_lock+0xc2/0x1220 [ 214.670162][ T1076] ? prep_new_page+0x19f/0x200 [ 214.674998][ T1076] ? wbc_attach_and_unlock_inode+0x515/0x920 [ 214.680980][ T1076] ? find_held_lock+0x35/0x130 [ 214.685812][ T1076] ? wbc_attach_and_unlock_inode+0x515/0x920 [ 214.692029][ T1076] ? ext4_mark_inode_dirty+0x9b0/0x9b0 [ 214.697491][ T1076] do_writepages+0xfa/0x2a0 [ 214.702500][ T1076] ? do_writepages+0xfa/0x2a0 [ 214.707267][ T1076] ? lock_downgrade+0x920/0x920 [ 214.712165][ T1076] ? page_writeback_cpu_online+0x20/0x20 [ 214.717807][ T1076] ? __kasan_check_read+0x11/0x20 [ 214.723660][ T1076] ? do_raw_spin_unlock+0x57/0x270 [ 214.728947][ T1076] ? _raw_spin_unlock+0x28/0x40 [ 214.733849][ T1076] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 214.740117][ T1076] ? wbc_attach_and_unlock_inode+0x5bf/0x920 [ 214.746165][ T1076] __filemap_fdatawrite_range+0x2bc/0x3b0 [ 214.751923][ T1076] ? delete_from_page_cache_batch+0xfe0/0xfe0 [ 214.757999][ T1076] ? lockdep_hardirqs_on+0x421/0x5e0 [ 214.763341][ T1076] filemap_flush+0x24/0x30 [ 214.767862][ T1076] collapse_file+0x36b1/0x41a0 [ 214.772796][ T1076] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 214.778980][ T1076] ? khugepaged+0x21d0/0x4360 [ 214.783767][ T1076] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 214.792160][ T1076] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 214.798059][ T1076] ? khugepaged_find_target_node+0x142/0x180 [ 214.804206][ T1076] khugepaged+0x2da9/0x4360 [ 214.808730][ T1076] ? __kasan_check_read+0x11/0x20 [ 214.813856][ T1076] ? __lock_acquire+0x16f2/0x4a00 [ 214.818892][ T1076] ? _raw_spin_unlock_irq+0x23/0x80 [ 214.824281][ T1076] ? finish_task_switch+0x147/0x750 [ 214.829491][ T1076] ? _raw_spin_unlock_irq+0x23/0x80 [ 214.834758][ T1076] ? lockdep_hardirqs_on+0x421/0x5e0 [ 214.840167][ T1076] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 214.845864][ T1076] ? lock_downgrade+0x920/0x920 [ 214.850733][ T1076] ? finish_wait+0x260/0x260 [ 214.856138][ T1076] ? lockdep_hardirqs_on+0x421/0x5e0 [ 214.861434][ T1076] ? trace_hardirqs_on+0x67/0x240 [ 214.866531][ T1076] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 214.873060][ T1076] ? __kthread_parkme+0x108/0x1c0 [ 214.878081][ T1076] ? __kasan_check_read+0x11/0x20 [ 214.883269][ T1076] kthread+0x361/0x430 [ 214.887346][ T1076] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 214.893028][ T1076] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 214.899210][ T1076] ret_from_fork+0x24/0x30 [ 214.903768][ T1076] [ 214.903768][ T1076] Showing all locks held in the system: [ 214.914288][ T1076] 4 locks held by kworker/u4:3/305: [ 214.919475][ T1076] #0: ffff8880a83b4d28 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740 [ 214.929651][ T1076] #1: ffff8880a8d27dc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 [ 214.941181][ T1076] #2: ffff8882159a80d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110 [ 214.951377][ T1076] #3: ffff8882159aa990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 [ 214.961252][ T1076] 1 lock held by khungtaskd/1076: [ 214.966323][ T1076] #0: ffffffff88faba80 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 [ 214.975680][ T1076] 1 lock held by khugepaged/1084: [ 214.980732][ T1076] #0: ffff8882159aa990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 [ 214.991443][ T1076] 1 lock held by rsyslogd/8671: [ 214.996371][ T1076] 2 locks held by getty/8761: [ 215.001056][ T1076] #0: ffff8880a1d73090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 215.012168][ T1076] #1: ffffc90005f452e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 215.022339][ T1076] 2 locks held by getty/8762: [ 215.027009][ T1076] #0: ffff8880a791e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 215.036141][ T1076] #1: ffffc90005f512e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 215.046301][ T1076] 2 locks held by getty/8763: [ 215.050981][ T1076] #0: ffff8880a40aa090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 215.060015][ T1076] #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 215.069653][ T1076] 2 locks held by getty/8764: [ 215.074384][ T1076] #0: ffff88809fc7b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 215.083400][ T1076] #1: ffffc90005f4d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 215.093025][ T1076] 2 locks held by getty/8765: [ 215.097697][ T1076] #0: ffff88808f8d6090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 215.106709][ T1076] #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 215.117043][ T1076] 2 locks held by getty/8766: [ 215.121791][ T1076] #0: ffff8880a8e5a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 215.131432][ T1076] #1: ffffc90005f492e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 215.141088][ T1076] 2 locks held by getty/8767: [ 215.145819][ T1076] #0: ffff88809b2bf090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 215.154850][ T1076] #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 215.164469][ T1076] 1 lock held by syz-execprog/8783: [ 215.170200][ T1076] #0: ffff888090dbb3a8 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7e/0xb2 [ 215.179514][ T1076] [ 215.181885][ T1076] ============================================= [ 215.181885][ T1076] [ 215.190286][ T1076] NMI backtrace for cpu 1 [ 215.194685][ T1076] CPU: 1 PID: 1076 Comm: khungtaskd Not tainted 5.4.0-rc4-next-20191025 #0 [ 215.203275][ T1076] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 215.213325][ T1076] Call Trace: [ 215.216614][ T1076] dump_stack+0x172/0x1f0 [ 215.221018][ T1076] nmi_cpu_backtrace.cold+0x70/0xb2 [ 215.226206][ T1076] ? vprintk_func+0x86/0x189 [ 215.230810][ T1076] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 215.236435][ T1076] nmi_trigger_cpumask_backtrace+0x23b/0x28b [ 215.242418][ T1076] arch_trigger_cpumask_backtrace+0x14/0x20 [ 215.248317][ T1076] watchdog+0xc8f/0x1350 [ 215.252557][ T1076] kthread+0x361/0x430 [ 215.256671][ T1076] ? reset_hung_task_detector+0x30/0x30 [ 215.262205][ T1076] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 215.267927][ T1076] ret_from_fork+0x24/0x30 [ 215.272450][ T1076] Sending NMI from CPU 1 to CPUs 0: [ 215.277714][ C0] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 [ 215.279434][ T1076] Kernel panic - not syncing: hung_task: blocked tasks [ 215.292802][ T1076] CPU: 1 PID: 1076 Comm: khungtaskd Not tainted 5.4.0-rc4-next-20191025 #0 [ 215.301498][ T1076] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 215.311563][ T1076] Call Trace: [ 215.314847][ T1076] dump_stack+0x172/0x1f0 [ 215.319258][ T1076] panic+0x2e3/0x75c [ 215.323138][ T1076] ? add_taint.cold+0x16/0x16 [ 215.327810][ T1076] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 215.333433][ T1076] ? ___preempt_schedule+0x16/0x18 [ 215.338537][ T1076] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 215.344667][ T1076] ? nmi_trigger_cpumask_backtrace+0x24c/0x28b [ 215.350798][ T1076] ? nmi_trigger_cpumask_backtrace+0x256/0x28b [ 215.357075][ T1076] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 215.363229][ T1076] watchdog+0xca0/0x1350 [ 215.367913][ T1076] kthread+0x361/0x430 [ 215.371986][ T1076] ? reset_hung_task_detector+0x30/0x30 [ 215.377536][ T1076] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 215.383345][ T1076] ret_from_fork+0x24/0x30 [ 215.389272][ T1076] Kernel Offset: disabled [ 215.393605][ T1076] Rebooting in 86400 seconds..