[ 53.529133][ T23] audit: type=1800 audit(1572603495.365:25): pid=8445 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 53.549004][ T23] audit: type=1800 audit(1572603495.365:26): pid=8445 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 53.584477][ T23] audit: type=1800 audit(1572603495.375:27): pid=8445 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. [ 54.305388][ T8512] sshd (8512) 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 '10.128.15.204' (ECDSA) to the list of known hosts. syzkaller login: [ 233.575625][ T1079] INFO: task khugepaged:1086 blocked for more than 143 seconds. [ 233.583528][ T1079] Not tainted 5.4.0-rc5-next-20191031 #0 [ 233.590778][ T1079] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 233.599500][ T1079] khugepaged D27840 1086 2 0x80004000 [ 233.610292][ T1079] Call Trace: [ 233.613590][ T1079] __schedule+0x94a/0x1e70 [ 233.618057][ T1079] ? __sched_text_start+0x8/0x8 [ 233.623213][ T1079] ? blk_insert_cloned_request+0x530/0x530 [ 233.629070][ T1079] ? _raw_spin_unlock_irq+0x23/0x80 [ 233.634425][ T1079] ? __lock_page+0x3d9/0xab0 [ 233.639060][ T1079] ? _raw_spin_unlock_irq+0x23/0x80 [ 233.644495][ T1079] schedule+0xdc/0x2b0 [ 233.648609][ T1079] io_schedule+0x1c/0x70 [ 233.652990][ T1079] __lock_page+0x422/0xab0 [ 233.657451][ T1079] ? wait_on_page_bit+0xa60/0xa60 [ 233.662620][ T1079] ? page_cache_next_miss+0x340/0x340 [ 233.668044][ T1079] ? ___might_sleep+0x163/0x2c0 [ 233.673028][ T1079] ? __might_sleep+0x95/0x190 [ 233.677755][ T1079] mpage_prepare_extent_to_map+0xb3f/0xf90 [ 233.683796][ T1079] ? mpage_process_page_bufs+0x780/0x780 [ 233.689496][ T1079] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 233.695515][ T1079] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 233.701753][ T1079] ext4_writepages+0xb6a/0x2e70 [ 233.706630][ T1079] ? __this_cpu_preempt_check+0x2c/0x190 [ 233.712285][ T1079] ? ext4_mark_inode_dirty+0x9b0/0x9b0 [ 233.718521][ T1079] ? 0xffffffff81000000 [ 233.722683][ T1079] ? mark_lock+0xc2/0x1220 [ 233.727133][ T1079] ? prep_new_page+0x19f/0x200 [ 233.731915][ T1079] ? wbc_attach_and_unlock_inode+0x515/0x920 [ 233.737951][ T1079] ? find_held_lock+0x35/0x130 [ 233.742718][ T1079] ? wbc_attach_and_unlock_inode+0x515/0x920 [ 233.748750][ T1079] ? ext4_mark_inode_dirty+0x9b0/0x9b0 [ 233.754211][ T1079] do_writepages+0xfa/0x2a0 [ 233.758763][ T1079] ? do_writepages+0xfa/0x2a0 [ 233.763430][ T1079] ? lock_downgrade+0x920/0x920 [ 233.768325][ T1079] ? page_writeback_cpu_online+0x20/0x20 [ 233.773956][ T1079] ? __kasan_check_read+0x11/0x20 [ 233.779018][ T1079] ? do_raw_spin_unlock+0x57/0x270 [ 233.784147][ T1079] ? _raw_spin_unlock+0x28/0x40 [ 233.789042][ T1079] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 233.795300][ T1079] ? wbc_attach_and_unlock_inode+0x5bf/0x920 [ 233.801348][ T1079] __filemap_fdatawrite_range+0x2bc/0x3b0 [ 233.807105][ T1079] ? delete_from_page_cache_batch+0xfe0/0xfe0 [ 233.813174][ T1079] ? lockdep_hardirqs_on+0x421/0x5e0 [ 233.818672][ T1079] filemap_flush+0x24/0x30 [ 233.823094][ T1079] collapse_file+0x36b1/0x41a0 [ 233.831119][ T1079] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 233.837304][ T1079] ? khugepaged+0x21c0/0x4360 [ 233.841965][ T1079] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 233.850927][ T1079] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 233.856689][ T1079] ? khugepaged_find_target_node+0x142/0x180 [ 233.862674][ T1079] khugepaged+0x2da9/0x4360 [ 233.867232][ T1079] ? __kasan_check_read+0x11/0x20 [ 233.872250][ T1079] ? __lock_acquire+0x16f2/0x4a00 [ 233.877345][ T1079] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 233.882974][ T1079] ? lock_downgrade+0x920/0x920 [ 233.887860][ T1079] ? finish_wait+0x260/0x260 [ 233.892463][ T1079] ? lockdep_hardirqs_on+0x421/0x5e0 [ 233.897814][ T1079] ? trace_hardirqs_on+0x67/0x240 [ 233.902844][ T1079] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 233.909120][ T1079] ? __kthread_parkme+0x108/0x1c0 [ 233.914140][ T1079] ? __kasan_check_read+0x11/0x20 [ 233.919229][ T1079] kthread+0x361/0x430 [ 233.923304][ T1079] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 233.928995][ T1079] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 233.934719][ T1079] ret_from_fork+0x24/0x30 [ 233.939333][ T1079] [ 233.939333][ T1079] Showing all locks held in the system: [ 233.947083][ T1079] 4 locks held by kworker/u4:2/66: [ 233.952180][ T1079] #0: ffff8880a79c5528 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740 [ 233.962304][ T1079] #1: ffff8880a940fdc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 [ 233.973632][ T1079] #2: ffff88809b25a0d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110 [ 233.983875][ T1079] #3: ffff88809b25c990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 [ 233.993721][ T1079] 1 lock held by khungtaskd/1079: [ 233.998768][ T1079] #0: ffffffff88faba40 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 [ 234.008106][ T1079] 1 lock held by khugepaged/1086: [ 234.013119][ T1079] #0: ffff88809b25c990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 [ 234.023033][ T1079] 1 lock held by rsyslogd/8483: [ 234.027918][ T1079] #0: ffff888095e9e360 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 [ 234.036556][ T1079] 2 locks held by getty/8573: [ 234.041220][ T1079] #0: ffff8880995ec090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 234.050307][ T1079] #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 234.059901][ T1079] 2 locks held by getty/8574: [ 234.064569][ T1079] #0: ffff8880a29cd090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 234.073531][ T1079] #1: ffffc90005f2d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 234.083127][ T1079] 2 locks held by getty/8575: [ 234.087837][ T1079] #0: ffff8880a1109090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 234.096842][ T1079] #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 234.107187][ T1079] 2 locks held by getty/8576: [ 234.111847][ T1079] #0: ffff8880a7bfb090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 234.120834][ T1079] #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 234.130441][ T1079] 2 locks held by getty/8577: [ 234.135102][ T1079] #0: ffff888095c15090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 234.144110][ T1079] #1: ffffc90005f412e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 234.153710][ T1079] 2 locks held by getty/8578: [ 234.158429][ T1079] #0: ffff8880a4aa5090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 234.167407][ T1079] #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 234.177002][ T1079] 2 locks held by getty/8579: [ 234.181668][ T1079] #0: ffff8880a78e5090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 234.190646][ T1079] #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 234.200303][ T1079] 1 lock held by syz-execprog/8602: [ 234.205551][ T1079] #0: ffff8880a2d5e3a8 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7e/0xb2 [ 234.214771][ T1079] [ 234.217127][ T1079] ============================================= [ 234.217127][ T1079] [ 234.225570][ T1079] NMI backtrace for cpu 1 [ 234.229894][ T1079] CPU: 1 PID: 1079 Comm: khungtaskd Not tainted 5.4.0-rc5-next-20191031 #0 [ 234.238458][ T1079] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 234.248490][ T1079] Call Trace: [ 234.251816][ T1079] dump_stack+0x172/0x1f0 [ 234.256142][ T1079] nmi_cpu_backtrace.cold+0x70/0xb2 [ 234.261321][ T1079] ? vprintk_func+0x86/0x189 [ 234.265892][ T1079] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 234.271512][ T1079] nmi_trigger_cpumask_backtrace+0x23b/0x28b [ 234.277503][ T1079] arch_trigger_cpumask_backtrace+0x14/0x20 [ 234.283382][ T1079] watchdog+0xc8f/0x1350 [ 234.287613][ T1079] kthread+0x361/0x430 [ 234.291662][ T1079] ? reset_hung_task_detector+0x30/0x30 [ 234.297188][ T1079] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 234.302897][ T1079] ret_from_fork+0x24/0x30 [ 234.307423][ T1079] Sending NMI from CPU 1 to CPUs 0: [ 234.312758][ C0] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 [ 234.314477][ T1079] Kernel panic - not syncing: hung_task: blocked tasks [ 234.327840][ T1079] CPU: 1 PID: 1079 Comm: khungtaskd Not tainted 5.4.0-rc5-next-20191031 #0 [ 234.336416][ T1079] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 234.346455][ T1079] Call Trace: [ 234.349745][ T1079] dump_stack+0x172/0x1f0 [ 234.354128][ T1079] panic+0x2e3/0x75c [ 234.358037][ T1079] ? add_taint.cold+0x16/0x16 [ 234.362695][ T1079] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 234.368311][ T1079] ? ___preempt_schedule+0x16/0x18 [ 234.373403][ T1079] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 234.379534][ T1079] ? nmi_trigger_cpumask_backtrace+0x24c/0x28b [ 234.385680][ T1079] ? nmi_trigger_cpumask_backtrace+0x256/0x28b [ 234.391848][ T1079] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 234.397994][ T1079] watchdog+0xca0/0x1350 [ 234.402231][ T1079] kthread+0x361/0x430 [ 234.406284][ T1079] ? reset_hung_task_detector+0x30/0x30 [ 234.411814][ T1079] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 234.417531][ T1079] ret_from_fork+0x24/0x30 [ 234.423557][ T1079] Kernel Offset: disabled [ 234.427888][ T1079] Rebooting in 86400 seconds..