[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 58.991597][ T27] audit: type=1800 audit(1571798699.362:25): pid=8425 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 59.029799][ T27] audit: type=1800 audit(1571798699.362:26): pid=8425 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 59.061826][ T27] audit: type=1800 audit(1571798699.372:27): pid=8425 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 '10.128.1.44' (ECDSA) to the list of known hosts. 2019/10/23 02:45:09 fuzzer started 2019/10/23 02:45:11 dialing manager at 10.128.0.26:45989 2019/10/23 02:45:11 syscalls: 2525 2019/10/23 02:45:11 code coverage: enabled 2019/10/23 02:45:11 comparison tracing: enabled 2019/10/23 02:45:11 extra coverage: extra coverage is not supported by the kernel 2019/10/23 02:45:11 setuid sandbox: enabled 2019/10/23 02:45:11 namespace sandbox: enabled 2019/10/23 02:45:11 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 02:45:11 fault injection: enabled 2019/10/23 02:45:11 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 02:45:11 net packet injection: enabled 2019/10/23 02:45:11 net device setup: enabled 2019/10/23 02:45:11 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 79.263940][ T1080] ------------[ cut here ]------------ [ 79.269461][ T1080] WARNING: CPU: 1 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 79.278635][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 79.285223][ T1080] CPU: 1 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 79.293806][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 79.303848][ T1080] Call Trace: [ 79.307130][ T1080] dump_stack+0x172/0x1f0 [ 79.311441][ T1080] ? collapse_file+0x1ef0/0x4170 [ 79.316357][ T1080] panic+0x2e3/0x75c [ 79.320226][ T1080] ? add_taint.cold+0x16/0x16 [ 79.324945][ T1080] ? printk+0xba/0xed [ 79.328921][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 79.334359][ T1080] ? __warn.cold+0x14/0x35 [ 79.338749][ T1080] ? __warn+0xd9/0x1d0 [ 79.342799][ T1080] ? collapse_file+0x1f9d/0x4170 [ 79.347717][ T1080] __warn.cold+0x2f/0x35 [ 79.351940][ T1080] ? report_bug.cold+0x63/0xb2 [ 79.356681][ T1080] ? collapse_file+0x1f9d/0x4170 [ 79.361604][ T1080] report_bug+0x289/0x300 [ 79.365913][ T1080] do_error_trap+0x11b/0x200 [ 79.370483][ T1080] do_invalid_op+0x37/0x50 [ 79.374878][ T1080] ? collapse_file+0x1f9d/0x4170 [ 79.379802][ T1080] invalid_op+0x23/0x30 [ 79.383953][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 79.389474][ 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 [ 79.409061][ T1080] RSP: 0018:ffff8880a7f1fad0 EFLAGS: 00010293 [ 79.415121][ T1080] RAX: ffff8880a7f12440 RBX: ffff8880a7f1fc88 RCX: ffffffff81b2b688 [ 79.423070][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 79.431018][ T1080] RBP: ffff8880a7f1fcb0 R08: ffff8880a7f12440 R09: fffff9400046afa9 [ 79.438964][ T1080] R10: fffff9400046afa8 R11: ffffea0002357d47 R12: 0000000000000001 [ 79.446923][ T1080] R13: ffffea0002406888 R14: 0000000000000000 R15: ffffea00021f0000 [ 79.454894][ T1080] ? collapse_file+0x1c78/0x4170 [ 79.459811][ T1080] ? collapse_file+0x1f9d/0x4170 [ 79.464729][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 79.470870][ T1080] ? khugepaged+0x21d0/0x4360 [ 79.475555][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 79.483613][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 79.489309][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 79.495279][ T1080] khugepaged+0x2da9/0x4360 [ 79.499769][ T1080] ? __kasan_check_read+0x11/0x20 [ 79.504770][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 79.509773][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 79.514967][ T1080] ? finish_task_switch+0x147/0x750 [ 79.520147][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 79.525330][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 79.530599][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 79.536217][ T1080] ? lock_downgrade+0x920/0x920 [ 79.541048][ T1080] ? finish_wait+0x260/0x260 [ 79.545710][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 79.550972][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 79.555981][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 79.562194][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 79.567192][ T1080] ? __kasan_check_read+0x11/0x20 [ 79.572192][ T1080] kthread+0x361/0x430 [ 79.576237][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 79.581844][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 79.587537][ T1080] ret_from_fork+0x24/0x30 [ 79.593423][ T1080] Kernel Offset: disabled [ 79.597815][ T1080] Rebooting in 86400 seconds..