[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 54.038575][ T23] audit: type=1800 audit(1571793708.298:25): pid=8402 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 54.085059][ T23] audit: type=1800 audit(1571793708.298:26): pid=8402 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 54.127882][ T23] audit: type=1800 audit(1571793708.298:27): pid=8402 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 '10.128.15.204' (ECDSA) to the list of known hosts. 2019/10/23 01:21:59 fuzzer started 2019/10/23 01:22:00 dialing manager at 10.128.0.26:45989 2019/10/23 01:22:00 syscalls: 2525 2019/10/23 01:22:00 code coverage: enabled 2019/10/23 01:22:00 comparison tracing: enabled 2019/10/23 01:22:00 extra coverage: extra coverage is not supported by the kernel 2019/10/23 01:22:00 setuid sandbox: enabled 2019/10/23 01:22:00 namespace sandbox: enabled 2019/10/23 01:22:00 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 01:22:00 fault injection: enabled 2019/10/23 01:22:00 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 01:22:00 net packet injection: enabled 2019/10/23 01:22:00 net device setup: enabled 2019/10/23 01:22:00 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 74.954522][ T1080] ------------[ cut here ]------------ [ 74.960061][ T1080] WARNING: CPU: 1 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 74.969089][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 74.975691][ T1080] CPU: 1 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 74.984273][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 74.994335][ T1080] Call Trace: [ 74.997650][ T1080] dump_stack+0x172/0x1f0 [ 75.002001][ T1080] ? collapse_file+0x1ef0/0x4170 [ 75.006946][ T1080] panic+0x2e3/0x75c [ 75.010845][ T1080] ? add_taint.cold+0x16/0x16 [ 75.015535][ T1080] ? printk+0xba/0xed [ 75.019534][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 75.025007][ T1080] ? __warn.cold+0x14/0x35 [ 75.029430][ T1080] ? __warn+0xd9/0x1d0 [ 75.033514][ T1080] ? collapse_file+0x1f9d/0x4170 [ 75.038469][ T1080] __warn.cold+0x2f/0x35 [ 75.042743][ T1080] ? report_bug.cold+0x63/0xb2 [ 75.047506][ T1080] ? collapse_file+0x1f9d/0x4170 [ 75.052458][ T1080] report_bug+0x289/0x300 [ 75.056844][ T1080] do_error_trap+0x11b/0x200 [ 75.061447][ T1080] do_invalid_op+0x37/0x50 [ 75.065888][ T1080] ? collapse_file+0x1f9d/0x4170 [ 75.070830][ T1080] invalid_op+0x23/0x30 [ 75.075012][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 75.080562][ 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 [ 75.101214][ T1080] RSP: 0018:ffff8880a7db7ad0 EFLAGS: 00010293 [ 75.107312][ T1080] RAX: ffff8880a7ee4440 RBX: ffff8880a7db7c88 RCX: ffffffff81b2b688 [ 75.115302][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 75.123285][ T1080] RBP: ffff8880a7db7cb0 R08: ffff8880a7ee4440 R09: fffff940004939c1 [ 75.131269][ T1080] R10: fffff940004939c0 R11: ffffea000249ce07 R12: 0000000000000001 [ 75.139258][ T1080] R13: ffffea0000279008 R14: 0000000000000000 R15: ffffea0002220000 [ 75.147269][ T1080] ? collapse_file+0x1c78/0x4170 [ 75.152253][ T1080] ? collapse_file+0x1f9d/0x4170 [ 75.157224][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 75.163402][ T1080] ? khugepaged+0x21d0/0x4360 [ 75.168178][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 75.176283][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 75.182017][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 75.188014][ T1080] khugepaged+0x2da9/0x4360 [ 75.192566][ T1080] ? __kasan_check_read+0x11/0x20 [ 75.197608][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 75.202642][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 75.207847][ T1080] ? finish_task_switch+0x147/0x750 [ 75.213055][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 75.218263][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 75.223570][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 75.229213][ T1080] ? lock_downgrade+0x920/0x920 [ 75.234070][ T1080] ? finish_wait+0x260/0x260 [ 75.238670][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 75.243963][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 75.249001][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 75.255270][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 75.260300][ T1080] ? __kasan_check_read+0x11/0x20 [ 75.265337][ T1080] kthread+0x361/0x430 [ 75.269515][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 75.275158][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 75.280891][ T1080] ret_from_fork+0x24/0x30 [ 75.286865][ T1080] Kernel Offset: disabled [ 75.291251][ T1080] Rebooting in 86400 seconds..