[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 55.078360][ T27] audit: type=1800 audit(1571800992.846:25): pid=8406 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 55.100076][ T27] audit: type=1800 audit(1571800992.856:26): pid=8406 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 55.137263][ T27] audit: type=1800 audit(1571800992.856:27): pid=8406 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 '10.128.15.216' (ECDSA) to the list of known hosts. 2019/10/23 03:23:22 fuzzer started 2019/10/23 03:23:25 dialing manager at 10.128.0.26:45989 2019/10/23 03:23:25 syscalls: 2525 2019/10/23 03:23:25 code coverage: enabled 2019/10/23 03:23:25 comparison tracing: enabled 2019/10/23 03:23:25 extra coverage: extra coverage is not supported by the kernel 2019/10/23 03:23:25 setuid sandbox: enabled 2019/10/23 03:23:25 namespace sandbox: enabled 2019/10/23 03:23:25 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 03:23:25 fault injection: enabled 2019/10/23 03:23:25 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 03:23:25 net packet injection: enabled 2019/10/23 03:23:25 net device setup: enabled 2019/10/23 03:23:25 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 75.013353][ T1079] ------------[ cut here ]------------ [ 75.018895][ T1079] WARNING: CPU: 1 PID: 1079 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 75.028037][ T1079] Kernel panic - not syncing: panic_on_warn set ... [ 75.034611][ T1079] CPU: 1 PID: 1079 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 75.043227][ T1079] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 75.053271][ T1079] Call Trace: [ 75.056564][ T1079] dump_stack+0x172/0x1f0 [ 75.060876][ T1079] ? collapse_file+0x1ef0/0x4170 [ 75.065807][ T1079] panic+0x2e3/0x75c [ 75.069698][ T1079] ? add_taint.cold+0x16/0x16 [ 75.074375][ T1079] ? printk+0xba/0xed [ 75.078334][ T1079] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 75.083786][ T1079] ? __warn.cold+0x14/0x35 [ 75.088201][ T1079] ? __warn+0xd9/0x1d0 [ 75.092250][ T1079] ? collapse_file+0x1f9d/0x4170 [ 75.097190][ T1079] __warn.cold+0x2f/0x35 [ 75.101425][ T1079] ? report_bug.cold+0x63/0xb2 [ 75.106165][ T1079] ? collapse_file+0x1f9d/0x4170 [ 75.111081][ T1079] report_bug+0x289/0x300 [ 75.115400][ T1079] do_error_trap+0x11b/0x200 [ 75.119968][ T1079] do_invalid_op+0x37/0x50 [ 75.124478][ T1079] ? collapse_file+0x1f9d/0x4170 [ 75.129443][ T1079] invalid_op+0x23/0x30 [ 75.133643][ T1079] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 75.139172][ T1079] 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 [ 75.158792][ T1079] RSP: 0018:ffff8880a7f17ad0 EFLAGS: 00010293 [ 75.164838][ T1079] RAX: ffff8880a7ed6400 RBX: ffff8880a7f17c88 RCX: ffffffff81b2b688 [ 75.172788][ T1079] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 75.180752][ T1079] RBP: ffff8880a7f17cb0 R08: ffff8880a7ed6400 R09: fffff940004804e9 [ 75.188716][ T1079] R10: fffff940004804e8 R11: ffffea0002402747 R12: 0000000000000001 [ 75.196759][ T1079] R13: ffffea00024457c8 R14: 0000000000000000 R15: ffffea0002248000 [ 75.204743][ T1079] ? collapse_file+0x1c78/0x4170 [ 75.209678][ T1079] ? collapse_file+0x1f9d/0x4170 [ 75.214599][ T1079] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 75.220751][ T1079] ? khugepaged+0x21d0/0x4360 [ 75.225415][ T1079] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 75.233578][ T1079] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 75.239275][ T1079] ? khugepaged_find_target_node+0x142/0x180 [ 75.245232][ T1079] khugepaged+0x2da9/0x4360 [ 75.249727][ T1079] ? __kasan_check_read+0x11/0x20 [ 75.254749][ T1079] ? __lock_acquire+0x16f2/0x4a00 [ 75.259754][ T1079] ? _raw_spin_unlock_irq+0x23/0x80 [ 75.264929][ T1079] ? finish_task_switch+0x147/0x750 [ 75.270105][ T1079] ? _raw_spin_unlock_irq+0x23/0x80 [ 75.275288][ T1079] ? lockdep_hardirqs_on+0x421/0x5e0 [ 75.280671][ T1079] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 75.286309][ T1079] ? lock_downgrade+0x920/0x920 [ 75.291151][ T1079] ? finish_wait+0x260/0x260 [ 75.295738][ T1079] ? lockdep_hardirqs_on+0x421/0x5e0 [ 75.301018][ T1079] ? trace_hardirqs_on+0x67/0x240 [ 75.306022][ T1079] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 75.312240][ T1079] ? __kthread_parkme+0x108/0x1c0 [ 75.317240][ T1079] ? __kasan_check_read+0x11/0x20 [ 75.322242][ T1079] kthread+0x361/0x430 [ 75.326313][ T1079] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 75.331950][ T1079] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 75.337664][ T1079] ret_from_fork+0x24/0x30 [ 75.343796][ T1079] Kernel Offset: disabled [ 75.348198][ T1079] Rebooting in 86400 seconds..