[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 54.490026][ T23] audit: type=1800 audit(1571644789.060:25): pid=8661 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 54.526559][ T23] audit: type=1800 audit(1571644789.060:26): pid=8661 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 54.566730][ T23] audit: type=1800 audit(1571644789.070:27): pid=8661 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 '10.128.0.229' (ECDSA) to the list of known hosts. 2019/10/21 07:59:58 fuzzer started 2019/10/21 08:00:00 dialing manager at 10.128.0.26:40119 2019/10/21 08:00:01 syscalls: 2525 2019/10/21 08:00:01 code coverage: enabled 2019/10/21 08:00:01 comparison tracing: enabled 2019/10/21 08:00:01 extra coverage: extra coverage is not supported by the kernel 2019/10/21 08:00:01 setuid sandbox: enabled 2019/10/21 08:00:01 namespace sandbox: enabled 2019/10/21 08:00:01 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/21 08:00:01 fault injection: enabled 2019/10/21 08:00:01 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/21 08:00:01 net packet injection: enabled 2019/10/21 08:00:01 net device setup: enabled 2019/10/21 08:00:01 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 74.393133][ T1080] ------------[ cut here ]------------ [ 74.398786][ T1080] WARNING: CPU: 0 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 74.407792][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 74.414361][ T1080] CPU: 0 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191021 #0 [ 74.422919][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 74.432976][ T1080] Call Trace: [ 74.436265][ T1080] dump_stack+0x172/0x1f0 [ 74.440601][ T1080] ? collapse_file+0x1ee0/0x4170 [ 74.445533][ T1080] panic+0x2e3/0x75c [ 74.449409][ T1080] ? add_taint.cold+0x16/0x16 [ 74.454062][ T1080] ? printk+0xba/0xed [ 74.458021][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 74.463472][ T1080] ? __warn.cold+0x14/0x35 [ 74.467869][ T1080] ? __warn+0xd9/0x1d0 [ 74.471915][ T1080] ? collapse_file+0x1f9d/0x4170 [ 74.476843][ T1080] __warn.cold+0x2f/0x35 [ 74.481080][ T1080] ? report_bug.cold+0x63/0xb2 [ 74.485820][ T1080] ? collapse_file+0x1f9d/0x4170 [ 74.490735][ T1080] report_bug+0x289/0x300 [ 74.495060][ T1080] do_error_trap+0x11b/0x200 [ 74.499630][ T1080] do_invalid_op+0x37/0x50 [ 74.504020][ T1080] ? collapse_file+0x1f9d/0x4170 [ 74.508959][ T1080] invalid_op+0x23/0x30 [ 74.513105][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 74.518633][ 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 [ 74.538273][ T1080] RSP: 0018:ffff8880a7e57ad0 EFLAGS: 00010293 [ 74.544334][ T1080] RAX: ffff8880a7e74440 RBX: ffff8880a7e57c88 RCX: ffffffff81b2a998 [ 74.552325][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2acbd RDI: 0000000000000001 [ 74.560291][ T1080] RBP: ffff8880a7e57cb0 R08: ffff8880a7e74440 R09: fffff940004730b1 [ 74.568255][ T1080] R10: fffff940004730b0 R11: ffffea0002398587 R12: 0000000000000001 [ 74.576218][ T1080] R13: ffffea0002ffa848 R14: 0000000000000000 R15: ffffea0002230000 [ 74.584177][ T1080] ? collapse_file+0x1c78/0x4170 [ 74.589090][ T1080] ? collapse_file+0x1f9d/0x4170 [ 74.594011][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 74.600151][ T1080] ? khugepaged+0x21c0/0x4360 [ 74.604832][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 74.612900][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 74.618649][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 74.624618][ T1080] khugepaged+0x2da9/0x4360 [ 74.629117][ T1080] ? __kasan_check_read+0x11/0x20 [ 74.634207][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 74.639245][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 74.644424][ T1080] ? finish_task_switch+0x147/0x750 [ 74.649612][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 74.654788][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 74.660064][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 74.665772][ T1080] ? lock_downgrade+0x920/0x920 [ 74.670603][ T1080] ? finish_wait+0x260/0x260 [ 74.675172][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 74.680437][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 74.685446][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 74.691663][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 74.696663][ T1080] ? __kasan_check_read+0x11/0x20 [ 74.701682][ T1080] kthread+0x361/0x430 [ 74.705729][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 74.711425][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 74.717136][ T1080] ret_from_fork+0x24/0x30 [ 74.723277][ T1080] Kernel Offset: disabled [ 74.727684][ T1080] Rebooting in 86400 seconds..