[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 55.619169][ T27] audit: type=1800 audit(1571798223.535:25): pid=8338 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 55.663566][ T27] audit: type=1800 audit(1571798223.535:26): pid=8338 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 55.714095][ T27] audit: type=1800 audit(1571798223.535:27): pid=8338 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 '10.128.0.186' (ECDSA) to the list of known hosts. 2019/10/23 02:37:14 fuzzer started 2019/10/23 02:37:15 dialing manager at 10.128.0.26:45989 2019/10/23 02:37:15 syscalls: 2525 2019/10/23 02:37:15 code coverage: enabled 2019/10/23 02:37:15 comparison tracing: enabled 2019/10/23 02:37:15 extra coverage: extra coverage is not supported by the kernel 2019/10/23 02:37:15 setuid sandbox: enabled 2019/10/23 02:37:15 namespace sandbox: enabled 2019/10/23 02:37:15 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 02:37:15 fault injection: enabled 2019/10/23 02:37:15 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 02:37:15 net packet injection: enabled 2019/10/23 02:37:15 net device setup: enabled 2019/10/23 02:37:15 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 76.776179][ T1080] ------------[ cut here ]------------ [ 76.781692][ T1080] WARNING: CPU: 0 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 76.790704][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 76.797291][ T1080] CPU: 0 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 76.805937][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 76.815967][ T1080] Call Trace: [ 76.819240][ T1080] dump_stack+0x172/0x1f0 [ 76.823549][ T1080] ? collapse_file+0x1ef0/0x4170 [ 76.828516][ T1080] panic+0x2e3/0x75c [ 76.832392][ T1080] ? add_taint.cold+0x16/0x16 [ 76.837044][ T1080] ? printk+0xba/0xed [ 76.840998][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 76.846430][ T1080] ? __warn.cold+0x14/0x35 [ 76.850858][ T1080] ? __warn+0xd9/0x1d0 [ 76.854907][ T1080] ? collapse_file+0x1f9d/0x4170 [ 76.859818][ T1080] __warn.cold+0x2f/0x35 [ 76.864045][ T1080] ? report_bug.cold+0x63/0xb2 [ 76.868788][ T1080] ? collapse_file+0x1f9d/0x4170 [ 76.873704][ T1080] report_bug+0x289/0x300 [ 76.878043][ T1080] do_error_trap+0x11b/0x200 [ 76.882609][ T1080] do_invalid_op+0x37/0x50 [ 76.887000][ T1080] ? collapse_file+0x1f9d/0x4170 [ 76.891912][ T1080] invalid_op+0x23/0x30 [ 76.896055][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 76.901575][ 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 [ 76.921155][ T1080] RSP: 0018:ffff8880a7ef7ad0 EFLAGS: 00010293 [ 76.927197][ T1080] RAX: ffff8880a7de2440 RBX: ffff8880a7ef7c88 RCX: ffffffff81b2b688 [ 76.935142][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 76.943090][ T1080] RBP: ffff8880a7ef7cb0 R08: ffff8880a7de2440 R09: fffff9400047cb41 [ 76.951037][ T1080] R10: fffff9400047cb40 R11: ffffea00023e5a07 R12: 0000000000000001 [ 76.958982][ T1080] R13: ffffea00023a75c8 R14: 0000000000000000 R15: ffffea00021f0000 [ 76.966941][ T1080] ? collapse_file+0x1c78/0x4170 [ 76.971855][ T1080] ? collapse_file+0x1f9d/0x4170 [ 76.976772][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 76.982905][ T1080] ? khugepaged+0x21d0/0x4360 [ 76.987561][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 76.995637][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 77.001330][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 77.007286][ T1080] khugepaged+0x2da9/0x4360 [ 77.011767][ T1080] ? __kasan_check_read+0x11/0x20 [ 77.016880][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 77.021894][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 77.027069][ T1080] ? finish_task_switch+0x147/0x750 [ 77.032240][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 77.037414][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 77.042679][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 77.048293][ T1080] ? lock_downgrade+0x920/0x920 [ 77.053128][ T1080] ? finish_wait+0x260/0x260 [ 77.057696][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 77.062968][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 77.067984][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 77.074201][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 77.079199][ T1080] ? __kasan_check_read+0x11/0x20 [ 77.084200][ T1080] kthread+0x361/0x430 [ 77.088245][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 77.093863][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 77.099570][ T1080] ret_from_fork+0x24/0x30 [ 77.105213][ T1080] Kernel Offset: disabled [ 77.109602][ T1080] Rebooting in 86400 seconds..