[ 54.769708][ T23] audit: type=1800 audit(1572459591.688:25): pid=8575 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0
[ 54.794782][ T23] audit: type=1800 audit(1572459591.688:26): pid=8575 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0
[ 54.840647][ T23] audit: type=1800 audit(1572459591.698:27): pid=8575 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[1G[[32m ok [39;49m8[?25h[?0c.
[ 55.247711][ T8642] sshd (8642) used greatest stack depth: 22888 bytes left
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
Debian GNU/Linux 7 syzkaller ttyS0
Warning: Permanently added '10.128.10.55' (ECDSA) to the list of known hosts.
syzkaller login: [ 214.534630][ T1078] INFO: task khugepaged:1085 blocked for more than 143 seconds.
[ 214.542450][ T1078] Not tainted 5.4.0-rc5-next-20191030 #0
[ 214.549425][ T1078] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 214.558210][ T1078] khugepaged D27840 1085 2 0x80004000
[ 214.564601][ T1078] Call Trace:
[ 214.567899][ T1078] __schedule+0x94a/0x1e70
[ 214.572336][ T1078] ? __sched_text_start+0x8/0x8
[ 214.577253][ T1078] ? blk_insert_cloned_request+0x530/0x530
[ 214.583100][ T1078] ? _raw_spin_unlock_irq+0x23/0x80
[ 214.588354][ T1078] ? __lock_page+0x3d9/0xab0
[ 214.592984][ T1078] ? _raw_spin_unlock_irq+0x23/0x80
[ 214.598258][ T1078] schedule+0xdc/0x2b0
[ 214.602348][ T1078] io_schedule+0x1c/0x70
[ 214.606655][ T1078] __lock_page+0x422/0xab0
[ 214.611095][ T1078] ? wait_on_page_bit+0xa60/0xa60
[ 214.616554][ T1078] ? page_cache_next_miss+0x340/0x340
[ 214.621951][ T1078] ? ___might_sleep+0x163/0x2c0
[ 214.626860][ T1078] ? __might_sleep+0x95/0x190
[ 214.631546][ T1078] mpage_prepare_extent_to_map+0xb3f/0xf90
[ 214.637475][ T1078] ? mpage_process_page_bufs+0x780/0x780
[ 214.643125][ T1078] ? rcu_read_lock_any_held.part.0+0x50/0x50
[ 214.649286][ T1078] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[ 214.655591][ T1078] ext4_writepages+0xb6a/0x2e70
[ 214.660489][ T1078] ? __this_cpu_preempt_check+0x2c/0x190
[ 214.666190][ T1078] ? ext4_mark_inode_dirty+0x9b0/0x9b0
[ 214.671655][ T1078] ? 0xffffffff81000000
[ 214.676637][ T1078] ? mark_lock+0xc2/0x1220
[ 214.681087][ T1078] ? prep_new_page+0x19f/0x200
[ 214.685906][ T1078] ? wbc_attach_and_unlock_inode+0x515/0x920
[ 214.691901][ T1078] ? find_held_lock+0x35/0x130
[ 214.696716][ T1078] ? wbc_attach_and_unlock_inode+0x515/0x920
[ 214.702710][ T1078] ? ext4_mark_inode_dirty+0x9b0/0x9b0
[ 214.708227][ T1078] do_writepages+0xfa/0x2a0
[ 214.712747][ T1078] ? do_writepages+0xfa/0x2a0
[ 214.717487][ T1078] ? lock_downgrade+0x920/0x920
[ 214.722510][ T1078] ? page_writeback_cpu_online+0x20/0x20
[ 214.728225][ T1078] ? __kasan_check_read+0x11/0x20
[ 214.733299][ T1078] ? do_raw_spin_unlock+0x57/0x270
[ 214.738491][ T1078] ? _raw_spin_unlock+0x28/0x40
[ 214.743358][ T1078] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[ 214.749712][ T1078] ? wbc_attach_and_unlock_inode+0x5bf/0x920
[ 214.755769][ T1078] __filemap_fdatawrite_range+0x2bc/0x3b0
[ 214.761558][ T1078] ? delete_from_page_cache_batch+0xfe0/0xfe0
[ 214.767750][ T1078] ? lockdep_hardirqs_on+0x421/0x5e0
[ 214.773043][ T1078] filemap_flush+0x24/0x30
[ 214.777515][ T1078] collapse_file+0x36b1/0x41a0
[ 214.782290][ T1078] ? rcu_lockdep_current_cpu_online+0xe3/0x130
[ 214.788682][ T1078] ? khugepaged+0x2230/0x4360
[ 214.793384][ T1078] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370
[ 214.801570][ T1078] ? __sanitizer_cov_trace_cmp4+0x16/0x20
[ 214.808025][ T1078] ? khugepaged_find_target_node+0x142/0x180
[ 214.814135][ T1078] khugepaged+0x2da9/0x4360
[ 214.818740][ T1078] ? __kasan_check_read+0x11/0x20
[ 214.823962][ T1078] ? __lock_acquire+0x16f2/0x4a00
[ 214.829047][ T1078] ? _raw_spin_unlock_irq+0x23/0x80
[ 214.834268][ T1078] ? finish_task_switch+0x147/0x750
[ 214.839529][ T1078] ? _raw_spin_unlock_irq+0x23/0x80
[ 214.844808][ T1078] ? lockdep_hardirqs_on+0x421/0x5e0
[ 214.850094][ T1078] ? collapse_pte_mapped_thp+0xbe0/0xbe0
[ 214.855779][ T1078] ? lock_downgrade+0x920/0x920
[ 214.860662][ T1078] ? finish_wait+0x260/0x260
[ 214.865292][ T1078] ? lockdep_hardirqs_on+0x421/0x5e0
[ 214.870575][ T1078] ? trace_hardirqs_on+0x67/0x240
[ 214.875659][ T1078] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20
[ 214.881912][ T1078] ? __kthread_parkme+0x108/0x1c0
[ 214.886997][ T1078] ? __kasan_check_read+0x11/0x20
[ 214.892061][ T1078] kthread+0x361/0x430
[ 214.896193][ T1078] ? collapse_pte_mapped_thp+0xbe0/0xbe0
[ 214.901848][ T1078] ? kthread_mod_delayed_work+0x1f0/0x1f0
[ 214.907613][ T1078] ret_from_fork+0x24/0x30
[ 214.912131][ T1078]
[ 214.912131][ T1078] Showing all locks held in the system:
[ 214.919937][ T1078] 4 locks held by kworker/u4:2/24:
[ 214.925086][ T1078] #0: ffff8880a786d928 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740
[ 214.935944][ T1078] #1: ffff8880a9a87dc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740
[ 214.947327][ T1078] #2: ffff88809b0c40d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110
[ 214.956946][ T1078] #3: ffff88809b0c6990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0
[ 214.966822][ T1078] 1 lock held by khungtaskd/1078:
[ 214.971843][ T1078] #0: ffffffff88faba40 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279
[ 214.981214][ T1078] 1 lock held by khugepaged/1085:
[ 214.986284][ T1078] #0: ffff88809b0c6990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0
[ 214.996205][ T1078] 1 lock held by rsyslogd/8613:
[ 215.001137][ T1078] #0: ffff88809aa5f360 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110
[ 215.009792][ T1078] 2 locks held by getty/8703:
[ 215.014461][ T1078] #0: ffff8880979e7090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
[ 215.023483][ T1078] #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0
[ 215.033089][ T1078] 2 locks held by getty/8704:
[ 215.037805][ T1078] #0: ffff8880984cf090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
[ 215.046818][ T1078] #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0
[ 215.056550][ T1078] 2 locks held by getty/8705:
[ 215.061327][ T1078] #0: ffff888099c8f090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
[ 215.071063][ T1078] #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0
[ 215.080700][ T1078] 2 locks held by getty/8706:
[ 215.085417][ T1078] #0: ffff88809ad8c090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
[ 215.094399][ T1078] #1: ffffc90005f092e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0
[ 215.104044][ T1078] 2 locks held by getty/8707:
[ 215.108764][ T1078] #0: ffff888099ff1090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
[ 215.117796][ T1078] #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0
[ 215.127409][ T1078] 2 locks held by getty/8708:
[ 215.132075][ T1078] #0: ffff8880a8398090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
[ 215.141228][ T1078] #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0
[ 215.150872][ T1078] 2 locks held by getty/8709:
[ 215.155674][ T1078] #0: ffff888092bb1090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
[ 215.164668][ T1078] #1: ffffc90005ef12e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0
[ 215.174225][ T1078] 1 lock held by syz-execprog/8732:
[ 215.179464][ T1078] #0: ffff8880a65ff368 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7e/0xb2
[ 215.189425][ T1078]
[ 215.191755][ T1078] =============================================
[ 215.191755][ T1078]
[ 215.200938][ T1078] NMI backtrace for cpu 1
[ 215.205350][ T1078] CPU: 1 PID: 1078 Comm: khungtaskd Not tainted 5.4.0-rc5-next-20191030 #0
[ 215.213946][ T1078] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 215.224028][ T1078] Call Trace:
[ 215.227318][ T1078] dump_stack+0x172/0x1f0
[ 215.231694][ T1078] nmi_cpu_backtrace.cold+0x70/0xb2
[ 215.236888][ T1078] ? vprintk_func+0x86/0x189
[ 215.241470][ T1078] ? lapic_can_unplug_cpu.cold+0x3a/0x3a
[ 215.247119][ T1078] nmi_trigger_cpumask_backtrace+0x23b/0x28b
[ 215.253102][ T1078] arch_trigger_cpumask_backtrace+0x14/0x20
[ 215.258987][ T1078] watchdog+0xc8f/0x1350
[ 215.263225][ T1078] kthread+0x361/0x430
[ 215.267280][ T1078] ? reset_hung_task_detector+0x30/0x30
[ 215.272813][ T1078] ? kthread_mod_delayed_work+0x1f0/0x1f0
[ 215.278608][ T1078] ret_from_fork+0x24/0x30
[ 215.283109][ T1078] Sending NMI from CPU 1 to CPUs 0:
[ 215.288618][ C0] NMI backtrace for cpu 0
[ 215.288624][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc5-next-20191030 #0
[ 215.288629][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 215.288633][ C0] RIP: 0010:arch_cpu_idle_enter+0x0/0x20
[ 215.288642][ C0] Code: e8 a5 49 85 00 48 8b 74 24 20 e9 f3 f1 ff ff 4c 89 ff e8 93 49 85 00 e9 16 f0 ff ff 4c 89 ff e8 86 49 85 00 e9 e2 ef ff ff 90 <55> 31 ff 48 89 e5 e8 15 0c 06 00 e8 30 cd fe ff 5d c3 0f 1f 40 00
[ 215.288646][ C0] RSP: 0018:ffffffff88e07d48 EFLAGS: 00000047
[ 215.288653][ C0] RAX: 0000000000000001 RBX: ffffffff88e7a1c0 RCX: ffffffff81517c07
[ 215.288657][ C0] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff89c80640
[ 215.288661][ C0] RBP: ffffffff88e07e10 R08: 1ffffffff13900c8 R09: fffffbfff13900c9
[ 215.288666][ C0] R10: fffffbfff13900c8 R11: ffffffff89c80647 R12: dffffc0000000000
[ 215.288670][ C0] R13: ffffffff89c80640 R14: ffffffff88e7a1c0 R15: 0000000000000000
[ 215.288675][ C0] FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
[ 215.288679][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 215.288683][ C0] CR2: ffffffffff600400 CR3: 00000000a390a000 CR4: 00000000001406f0
[ 215.288688][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 215.288692][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 215.288695][ C0] Call Trace:
[ 215.288698][ C0] ? do_idle+0x14a/0x6e0
[ 215.288701][ C0] ? __this_cpu_preempt_check+0x35/0x190
[ 215.288704][ C0] ? arch_cpu_idle_exit+0x80/0x80
[ 215.288707][ C0] cpu_startup_entry+0x1b/0x20
[ 215.288710][ C0] rest_init+0x23b/0x371
[ 215.288713][ C0] arch_call_rest_init+0xe/0x1b
[ 215.288716][ C0] start_kernel+0x904/0x943
[ 215.288719][ C0] ? mem_encrypt_init+0xb/0xb
[ 215.288723][ C0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[ 215.288726][ C0] ? x86_family+0x41/0x50
[ 215.288729][ C0] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20
[ 215.288732][ C0] x86_64_start_reservations+0x29/0x2b
[ 215.288736][ C0] x86_64_start_kernel+0x77/0x7b
[ 215.288739][ C0] secondary_startup_64+0xa4/0xb0
[ 215.289342][ T1078] Kernel panic - not syncing: hung_task: blocked tasks
[ 215.501872][ T1078] CPU: 1 PID: 1078 Comm: khungtaskd Not tainted 5.4.0-rc5-next-20191030 #0
[ 215.510445][ T1078] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 215.520506][ T1078] Call Trace:
[ 215.523802][ T1078] dump_stack+0x172/0x1f0
[ 215.528126][ T1078] panic+0x2e3/0x75c
[ 215.532004][ T1078] ? add_taint.cold+0x16/0x16
[ 215.536684][ T1078] ? __sanitizer_cov_trace_cmp4+0x16/0x20
[ 215.542760][ T1078] ? printk_safe_flush+0xf2/0x140
[ 215.547768][ T1078] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[ 215.554003][ T1078] ? nmi_trigger_cpumask_backtrace+0x224/0x28b
[ 215.560161][ T1078] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b
[ 215.566315][ T1078] watchdog+0xca0/0x1350
[ 215.570549][ T1078] kthread+0x361/0x430
[ 215.574624][ T1078] ? reset_hung_task_detector+0x30/0x30
[ 215.580156][ T1078] ? kthread_mod_delayed_work+0x1f0/0x1f0
[ 215.585868][ T1078] ret_from_fork+0x24/0x30
[ 215.591777][ T1078] Kernel Offset: disabled
[ 215.596116][ T1078] Rebooting in 86400 seconds..