[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 59.236845][ T27] audit: type=1800 audit(1571797695.357:25): pid=8407 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 59.281380][ T27] audit: type=1800 audit(1571797695.357:26): pid=8407 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 59.323316][ T27] audit: type=1800 audit(1571797695.367:27): pid=8407 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 '10.128.0.156' (ECDSA) to the list of known hosts. 2019/10/23 02:28:27 fuzzer started 2019/10/23 02:28:29 dialing manager at 10.128.0.26:45989 2019/10/23 02:28:29 syscalls: 2525 2019/10/23 02:28:29 code coverage: enabled 2019/10/23 02:28:29 comparison tracing: enabled 2019/10/23 02:28:29 extra coverage: extra coverage is not supported by the kernel 2019/10/23 02:28:29 setuid sandbox: enabled 2019/10/23 02:28:29 namespace sandbox: enabled 2019/10/23 02:28:29 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 02:28:29 fault injection: enabled 2019/10/23 02:28:29 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 02:28:29 net packet injection: enabled 2019/10/23 02:28:29 net device setup: enabled 2019/10/23 02:28:29 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 81.897783][ T1080] ------------[ cut here ]------------ [ 81.903478][ T1080] WARNING: CPU: 0 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 81.912690][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 81.919368][ T1080] CPU: 0 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 81.927932][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 81.937979][ T1080] Call Trace: [ 81.941255][ T1080] dump_stack+0x172/0x1f0 [ 81.945567][ T1080] ? collapse_file+0x1ef0/0x4170 [ 81.950483][ T1080] panic+0x2e3/0x75c [ 81.954369][ T1080] ? add_taint.cold+0x16/0x16 [ 81.959026][ T1080] ? printk+0xba/0xed [ 81.962983][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 81.968414][ T1080] ? __warn.cold+0x14/0x35 [ 81.972806][ T1080] ? __warn+0xd9/0x1d0 [ 81.976866][ T1080] ? collapse_file+0x1f9d/0x4170 [ 81.981782][ T1080] __warn.cold+0x2f/0x35 [ 81.986000][ T1080] ? report_bug.cold+0x63/0xb2 [ 81.990736][ T1080] ? collapse_file+0x1f9d/0x4170 [ 81.995651][ T1080] report_bug+0x289/0x300 [ 81.999969][ T1080] do_error_trap+0x11b/0x200 [ 82.004534][ T1080] do_invalid_op+0x37/0x50 [ 82.008922][ T1080] ? collapse_file+0x1f9d/0x4170 [ 82.013845][ T1080] invalid_op+0x23/0x30 [ 82.017975][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 82.023493][ 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 [ 82.043067][ T1080] RSP: 0018:ffff8880a7dafad0 EFLAGS: 00010293 [ 82.049106][ T1080] RAX: ffff8880a7da0440 RBX: ffff8880a7dafc88 RCX: ffffffff81b2b688 [ 82.057062][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 82.065008][ T1080] RBP: ffff8880a7dafcb0 R08: ffff8880a7da0440 R09: fffff94000465ab1 [ 82.072954][ T1080] R10: fffff94000465ab0 R11: ffffea000232d587 R12: 0000000000000001 [ 82.080906][ T1080] R13: ffffea00023bf208 R14: 0000000000000000 R15: ffffea00021d0000 [ 82.088865][ T1080] ? collapse_file+0x1c78/0x4170 [ 82.093787][ T1080] ? collapse_file+0x1f9d/0x4170 [ 82.098708][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 82.104841][ T1080] ? khugepaged+0x21d0/0x4360 [ 82.109518][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 82.117580][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 82.123285][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 82.129246][ T1080] khugepaged+0x2da9/0x4360 [ 82.133732][ T1080] ? __kasan_check_read+0x11/0x20 [ 82.138747][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 82.143752][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 82.148941][ T1080] ? finish_task_switch+0x147/0x750 [ 82.154112][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 82.159285][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 82.164554][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 82.170162][ T1080] ? lock_downgrade+0x920/0x920 [ 82.175105][ T1080] ? finish_wait+0x260/0x260 [ 82.179683][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 82.184942][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 82.189944][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 82.196164][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 82.201165][ T1080] ? __kasan_check_read+0x11/0x20 [ 82.206162][ T1080] kthread+0x361/0x430 [ 82.210217][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 82.215821][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 82.221527][ T1080] ret_from_fork+0x24/0x30 [ 82.227465][ T1080] Kernel Offset: disabled [ 82.231843][ T1080] Rebooting in 86400 seconds..