[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 62.192130][ T27] audit: type=1800 audit(1571805961.415:25): pid=8727 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 62.228611][ T27] audit: type=1800 audit(1571805961.415:26): pid=8727 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 62.268736][ T27] audit: type=1800 audit(1571805961.415:27): pid=8727 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 '10.128.1.55' (ECDSA) to the list of known hosts. 2019/10/23 04:46:12 fuzzer started 2019/10/23 04:46:14 dialing manager at 10.128.0.26:45337 2019/10/23 04:46:14 syscalls: 2525 2019/10/23 04:46:14 code coverage: enabled 2019/10/23 04:46:14 comparison tracing: enabled 2019/10/23 04:46:14 extra coverage: extra coverage is not supported by the kernel 2019/10/23 04:46:14 setuid sandbox: enabled 2019/10/23 04:46:14 namespace sandbox: enabled 2019/10/23 04:46:14 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 04:46:14 fault injection: enabled 2019/10/23 04:46:14 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 04:46:14 net packet injection: enabled 2019/10/23 04:46:14 net device setup: enabled 2019/10/23 04:46:14 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 84.162509][ T1080] ------------[ cut here ]------------ [ 84.168023][ T1080] WARNING: CPU: 0 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 84.177050][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 84.183645][ T1080] CPU: 0 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 84.192212][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 84.202441][ T1080] Call Trace: [ 84.205730][ T1080] dump_stack+0x172/0x1f0 [ 84.210046][ T1080] ? collapse_file+0x1ef0/0x4170 [ 84.214991][ T1080] panic+0x2e3/0x75c [ 84.218872][ T1080] ? add_taint.cold+0x16/0x16 [ 84.223538][ T1080] ? printk+0xba/0xed [ 84.227506][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 84.233052][ T1080] ? __warn.cold+0x14/0x35 [ 84.237458][ T1080] ? __warn+0xd9/0x1d0 [ 84.241514][ T1080] ? collapse_file+0x1f9d/0x4170 [ 84.246458][ T1080] __warn.cold+0x2f/0x35 [ 84.250690][ T1080] ? report_bug.cold+0x63/0xb2 [ 84.255449][ T1080] ? collapse_file+0x1f9d/0x4170 [ 84.260386][ T1080] report_bug+0x289/0x300 [ 84.264719][ T1080] do_error_trap+0x11b/0x200 [ 84.269310][ T1080] do_invalid_op+0x37/0x50 [ 84.273713][ T1080] ? collapse_file+0x1f9d/0x4170 [ 84.278653][ T1080] invalid_op+0x23/0x30 [ 84.282798][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 84.288329][ 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 [ 84.307924][ T1080] RSP: 0018:ffff8880a83f7ad0 EFLAGS: 00010293 [ 84.313988][ T1080] RAX: ffff8880a82de440 RBX: ffff8880a83f7c88 RCX: ffffffff81b2b688 [ 84.321961][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 84.329931][ T1080] RBP: ffff8880a83f7cb0 R08: ffff8880a82de440 R09: fffff9400047f6f1 [ 84.337904][ T1080] R10: fffff9400047f6f0 R11: ffffea00023fb787 R12: 0000000000000001 [ 84.345862][ T1080] R13: ffffea00022ff288 R14: 0000000000000000 R15: ffffea0002208000 [ 84.353842][ T1080] ? collapse_file+0x1c78/0x4170 [ 84.358763][ T1080] ? collapse_file+0x1f9d/0x4170 [ 84.363693][ T1080] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 84.369144][ T1080] ? khugepaged+0x21d0/0x4360 [ 84.373811][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 84.381897][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 84.387619][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 84.393607][ T1080] khugepaged+0x2da9/0x4360 [ 84.398120][ T1080] ? __kasan_check_read+0x11/0x20 [ 84.403162][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 84.408177][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 84.413363][ T1080] ? finish_task_switch+0x147/0x750 [ 84.418557][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 84.423769][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 84.429054][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 84.434674][ T1080] ? lock_downgrade+0x920/0x920 [ 84.439513][ T1080] ? finish_wait+0x260/0x260 [ 84.444089][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 84.449378][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 84.454391][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 84.460639][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 84.465662][ T1080] ? __kasan_check_read+0x11/0x20 [ 84.470679][ T1080] kthread+0x361/0x430 [ 84.474740][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 84.480365][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 84.486081][ T1080] ret_from_fork+0x24/0x30 [ 84.491930][ T1080] Kernel Offset: disabled [ 84.496471][ T1080] Rebooting in 86400 seconds..