[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 55.142501][ T26] audit: type=1800 audit(1571801516.871:25): pid=8401 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 55.181265][ T26] audit: type=1800 audit(1571801516.871:26): pid=8401 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 55.213253][ T26] audit: type=1800 audit(1571801516.881:27): pid=8401 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. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.115' (ECDSA) to the list of known hosts. 2019/10/23 03:32:04 fuzzer started syzkaller login: [ 62.748419][ T1080] ------------[ cut here ]------------ [ 62.753946][ T1080] WARNING: CPU: 1 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 62.763058][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 62.769655][ T1080] CPU: 1 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 62.778240][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.788303][ T1080] Call Trace: [ 62.791613][ T1080] dump_stack+0x172/0x1f0 [ 62.796063][ T1080] ? collapse_file+0x1ef0/0x4170 [ 62.801037][ T1080] panic+0x2e3/0x75c [ 62.804933][ T1080] ? add_taint.cold+0x16/0x16 [ 62.809607][ T1080] ? printk+0xba/0xed [ 62.813575][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 62.819039][ T1080] ? __warn.cold+0x14/0x35 [ 62.823453][ T1080] ? __warn+0xd9/0x1d0 [ 62.827538][ T1080] ? collapse_file+0x1f9d/0x4170 [ 62.832494][ T1080] __warn.cold+0x2f/0x35 [ 62.836739][ T1080] ? report_bug.cold+0x63/0xb2 [ 62.841491][ T1080] ? collapse_file+0x1f9d/0x4170 [ 62.846410][ T1080] report_bug+0x289/0x300 [ 62.850725][ T1080] do_error_trap+0x11b/0x200 [ 62.855296][ T1080] do_invalid_op+0x37/0x50 [ 62.859702][ T1080] ? collapse_file+0x1f9d/0x4170 [ 62.864636][ T1080] invalid_op+0x23/0x30 [ 62.868780][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 62.874372][ T1080] Code: a1 c0 ff 31 c9 ba 01 00 00 00 4c 89 fe 48 8b bd c0 fe ff ff e8 e4 e9 ec ff e9 b4 fd ff ff 4c 8b bd 88 fe ff ff e8 93 a1 c0 ff <0f> 0b 4c 8b a3 50 ff ff ff c7 85 80 fe ff ff 00 00 00 00 e9 05 f6 [ 62.894938][ T1080] RSP: 0018:ffff8880a7e77ad0 EFLAGS: 00010293 [ 62.900998][ T1080] RAX: ffff8880a7d80440 RBX: ffff8880a7e77c88 RCX: ffffffff81b2b688 [ 62.908962][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 62.916945][ T1080] RBP: ffff8880a7e77cb0 R08: ffff8880a7d80440 R09: fffff9400047fd99 [ 62.924898][ T1080] R10: fffff9400047fd98 R11: ffffea00023fecc7 R12: 0000000000000001 [ 62.932860][ T1080] R13: ffffea0002325e88 R14: 0000000000000000 R15: ffffea0002420000 [ 62.940824][ T1080] ? collapse_file+0x1c78/0x4170 [ 62.945743][ T1080] ? collapse_file+0x1f9d/0x4170 [ 62.950671][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 62.956825][ T1080] ? khugepaged+0x21d0/0x4360 [ 62.961508][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 62.969584][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 62.975313][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 62.981281][ T1080] khugepaged+0x2da9/0x4360 [ 62.985770][ T1080] ? __kasan_check_read+0x11/0x20 [ 62.990776][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 62.995964][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 63.001174][ T1080] ? finish_task_switch+0x147/0x750 [ 63.006361][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 63.011631][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 63.016914][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 63.022536][ T1080] ? lock_downgrade+0x920/0x920 [ 63.027393][ T1080] ? finish_wait+0x260/0x260 [ 63.031991][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 63.037265][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 63.042278][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 63.048505][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 63.053515][ T1080] ? __kasan_check_read+0x11/0x20 [ 63.058555][ T1080] kthread+0x361/0x430 [ 63.062612][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 63.068305][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 63.074014][ T1080] ret_from_fork+0x24/0x30 [ 63.079850][ T1080] Kernel Offset: disabled [ 63.084243][ T1080] Rebooting in 86400 seconds..