[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 60.885978][ T27] audit: type=1800 audit(1571794379.318:25): pid=8453 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 60.907536][ T27] audit: type=1800 audit(1571794379.318:26): pid=8453 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 60.947436][ T27] audit: type=1800 audit(1571794379.318:27): pid=8453 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 '10.128.0.243' (ECDSA) to the list of known hosts. syzkaller login: [ 69.163821][ T1080] ------------[ cut here ]------------ [ 69.169335][ T1080] WARNING: CPU: 1 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 69.178349][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 69.184933][ T1080] CPU: 1 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 69.193509][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 69.203561][ T1080] Call Trace: [ 69.206854][ T1080] dump_stack+0x172/0x1f0 [ 69.211197][ T1080] ? collapse_file+0x1ef0/0x4170 [ 69.216137][ T1080] panic+0x2e3/0x75c [ 69.220037][ T1080] ? add_taint.cold+0x16/0x16 [ 69.224728][ T1080] ? printk+0xba/0xed [ 69.228713][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 69.234198][ T1080] ? __warn.cold+0x14/0x35 [ 69.238618][ T1080] ? __warn+0xd9/0x1d0 [ 69.242692][ T1080] ? collapse_file+0x1f9d/0x4170 [ 69.247631][ T1080] __warn.cold+0x2f/0x35 [ 69.251877][ T1080] ? report_bug.cold+0x63/0xb2 [ 69.256644][ T1080] ? collapse_file+0x1f9d/0x4170 2019/10/23 01:33:07 fuzzer started [ 69.261586][ T1080] report_bug+0x289/0x300 [ 69.265916][ T1080] do_error_trap+0x11b/0x200 [ 69.270497][ T1080] do_invalid_op+0x37/0x50 [ 69.274898][ T1080] ? collapse_file+0x1f9d/0x4170 [ 69.279821][ T1080] invalid_op+0x23/0x30 [ 69.283961][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 69.289492][ 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 [ 69.309090][ T1080] RSP: 0018:ffff8880a7f2fad0 EFLAGS: 00010293 [ 69.315149][ T1080] RAX: ffff8880a7f24440 RBX: ffff8880a7f2fc88 RCX: ffffffff81b2b688 [ 69.323099][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 69.331065][ T1080] RBP: ffff8880a7f2fcb0 R08: ffff8880a7f24440 R09: fffff940004445b1 [ 69.339026][ T1080] R10: fffff940004445b0 R11: ffffea0002222d87 R12: 0000000000000001 [ 69.346981][ T1080] R13: ffffea000227b148 R14: 0000000000000000 R15: ffffea0002360000 [ 69.354956][ T1080] ? collapse_file+0x1c78/0x4170 [ 69.359881][ T1080] ? collapse_file+0x1f9d/0x4170 [ 69.364828][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 69.370974][ T1080] ? khugepaged+0x21d0/0x4360 [ 69.375656][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 69.383733][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 69.389441][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 69.395423][ T1080] khugepaged+0x2da9/0x4360 [ 69.399925][ T1080] ? __kasan_check_read+0x11/0x20 [ 69.404946][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 69.409962][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 69.415157][ T1080] ? finish_task_switch+0x147/0x750 [ 69.420337][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 69.425621][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 69.430961][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 69.436589][ T1080] ? lock_downgrade+0x920/0x920 [ 69.441442][ T1080] ? finish_wait+0x260/0x260 [ 69.446018][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 69.451284][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 69.456290][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 69.462520][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 69.467534][ T1080] ? __kasan_check_read+0x11/0x20 [ 69.472549][ T1080] kthread+0x361/0x430 [ 69.476645][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 69.482287][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 69.488006][ T1080] ret_from_fork+0x24/0x30 [ 69.493738][ T1080] Kernel Offset: disabled [ 69.498105][ T1080] Rebooting in 86400 seconds..