[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 55.913819][ T27] audit: type=1800 audit(1571789035.598:25): pid=8416 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 55.959589][ T27] audit: type=1800 audit(1571789035.598:26): pid=8416 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 55.996981][ T27] audit: type=1800 audit(1571789035.598:27): pid=8416 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 '10.128.0.109' (ECDSA) to the list of known hosts. 2019/10/23 00:04:06 fuzzer started syzkaller login: [ 66.733145][ T1080] ------------[ cut here ]------------ [ 66.738668][ T1080] WARNING: CPU: 1 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 66.747692][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 66.754314][ T1080] CPU: 1 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 66.762934][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.772994][ T1080] Call Trace: [ 66.776289][ T1080] dump_stack+0x172/0x1f0 [ 66.780873][ T1080] ? collapse_file+0x1ef0/0x4170 [ 66.785803][ T1080] panic+0x2e3/0x75c [ 66.789699][ T1080] ? add_taint.cold+0x16/0x16 [ 66.794368][ T1080] ? printk+0xba/0xed [ 66.798423][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 66.803879][ T1080] ? __warn.cold+0x14/0x35 [ 66.808286][ T1080] ? __warn+0xd9/0x1d0 [ 66.812365][ T1080] ? collapse_file+0x1f9d/0x4170 [ 66.817296][ T1080] __warn.cold+0x2f/0x35 [ 66.821571][ T1080] ? report_bug.cold+0x63/0xb2 [ 66.826340][ T1080] ? collapse_file+0x1f9d/0x4170 [ 66.831276][ T1080] report_bug+0x289/0x300 [ 66.835603][ T1080] do_error_trap+0x11b/0x200 [ 66.840185][ T1080] do_invalid_op+0x37/0x50 [ 66.844586][ T1080] ? collapse_file+0x1f9d/0x4170 [ 66.849523][ T1080] invalid_op+0x23/0x30 [ 66.853676][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 66.859218][ 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 [ 66.878896][ T1080] RSP: 0018:ffff8880a7ee7ad0 EFLAGS: 00010293 [ 66.884962][ T1080] RAX: ffff8880a7ec6440 RBX: ffff8880a7ee7c88 RCX: ffffffff81b2b688 [ 66.892945][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 66.900912][ T1080] RBP: ffff8880a7ee7cb0 R08: ffff8880a7ec6440 R09: fffff9400005db89 [ 66.908889][ T1080] R10: fffff9400005db88 R11: ffffea00002edc47 R12: 0000000000000001 [ 66.916856][ T1080] R13: ffffea00023dc748 R14: 0000000000000000 R15: ffffea0002338000 [ 66.924838][ T1080] ? collapse_file+0x1c78/0x4170 [ 66.929845][ T1080] ? collapse_file+0x1f9d/0x4170 [ 66.934794][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 66.940948][ T1080] ? khugepaged+0x21d0/0x4360 [ 66.945629][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 66.953702][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 66.959427][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 66.965402][ T1080] khugepaged+0x2da9/0x4360 [ 66.969901][ T1080] ? __kasan_check_read+0x11/0x20 [ 66.974943][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 66.980055][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 66.985263][ T1080] ? finish_task_switch+0x147/0x750 [ 66.990455][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 66.995653][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 67.000935][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 67.006559][ T1080] ? lock_downgrade+0x920/0x920 [ 67.011403][ T1080] ? finish_wait+0x260/0x260 [ 67.016018][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 67.021296][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 67.026416][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 67.032657][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 67.037675][ T1080] ? __kasan_check_read+0x11/0x20 [ 67.042725][ T1080] kthread+0x361/0x430 [ 67.046804][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 67.052436][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 67.058409][ T1080] ret_from_fork+0x24/0x30 [ 67.064372][ T1080] Kernel Offset: disabled [ 67.068898][ T1080] Rebooting in 86400 seconds..