[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 53.791131][ T27] audit: type=1800 audit(1571785762.617:25): pid=8466 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 53.812576][ T27] audit: type=1800 audit(1571785762.617:26): pid=8466 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 53.833110][ T27] audit: type=1800 audit(1571785762.617:27): pid=8466 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 '10.128.0.215' (ECDSA) to the list of known hosts. 2019/10/22 23:09:31 fuzzer started 2019/10/22 23:09:33 dialing manager at 10.128.0.26:45989 2019/10/22 23:09:33 syscalls: 2525 2019/10/22 23:09:33 code coverage: enabled 2019/10/22 23:09:33 comparison tracing: enabled 2019/10/22 23:09:33 extra coverage: extra coverage is not supported by the kernel 2019/10/22 23:09:33 setuid sandbox: enabled 2019/10/22 23:09:33 namespace sandbox: enabled 2019/10/22 23:09:33 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 23:09:33 fault injection: enabled 2019/10/22 23:09:33 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 23:09:33 net packet injection: enabled 2019/10/22 23:09:33 net device setup: enabled 2019/10/22 23:09:33 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 72.972510][ T1080] ------------[ cut here ]------------ [ 72.978060][ T1080] WARNING: CPU: 0 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 72.987082][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 72.993680][ T1080] CPU: 0 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 73.002255][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 73.012401][ T1080] Call Trace: [ 73.015698][ T1080] dump_stack+0x172/0x1f0 [ 73.020037][ T1080] ? collapse_file+0x1ef0/0x4170 [ 73.024977][ T1080] panic+0x2e3/0x75c [ 73.028878][ T1080] ? add_taint.cold+0x16/0x16 [ 73.033570][ T1080] ? printk+0xba/0xed [ 73.037559][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 73.043020][ T1080] ? __warn.cold+0x14/0x35 [ 73.047437][ T1080] ? __warn+0xd9/0x1d0 [ 73.051510][ T1080] ? collapse_file+0x1f9d/0x4170 [ 73.056447][ T1080] __warn.cold+0x2f/0x35 [ 73.060694][ T1080] ? report_bug.cold+0x63/0xb2 [ 73.065504][ T1080] ? collapse_file+0x1f9d/0x4170 [ 73.070446][ T1080] report_bug+0x289/0x300 [ 73.074780][ T1080] do_error_trap+0x11b/0x200 [ 73.079373][ T1080] do_invalid_op+0x37/0x50 [ 73.083796][ T1080] ? collapse_file+0x1f9d/0x4170 [ 73.088740][ T1080] invalid_op+0x23/0x30 [ 73.092895][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 73.098438][ 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 [ 73.118047][ T1080] RSP: 0018:ffff8880a7e67ad0 EFLAGS: 00010293 [ 73.124121][ T1080] RAX: ffff8880a7f36440 RBX: ffff8880a7e67c88 RCX: ffffffff81b2b688 [ 73.132094][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 73.140065][ T1080] RBP: ffff8880a7e67cb0 R08: ffff8880a7f36440 R09: fffff9400005d509 [ 73.148039][ T1080] R10: fffff9400005d508 R11: ffffea00002ea847 R12: 0000000000000001 [ 73.156011][ T1080] R13: ffffea00002e9648 R14: 0000000000000000 R15: ffffea0002228000 [ 73.163994][ T1080] ? collapse_file+0x1c78/0x4170 [ 73.168930][ T1080] ? collapse_file+0x1f9d/0x4170 [ 73.173877][ T1080] ? khugepaged+0x21d0/0x4360 [ 73.178556][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 73.186622][ T1080] ? rcu_preempt_deferred_qs_irqrestore+0x4ff/0xd60 [ 73.193223][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 73.198936][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 73.204909][ T1080] khugepaged+0x2da9/0x4360 [ 73.209413][ T1080] ? __kasan_check_read+0x11/0x20 [ 73.214441][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 73.219730][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 73.224928][ T1080] ? finish_task_switch+0x147/0x750 [ 73.230132][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 73.235340][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 73.240641][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 73.246274][ T1080] ? lock_downgrade+0x920/0x920 [ 73.251130][ T1080] ? finish_wait+0x260/0x260 [ 73.255727][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 73.261016][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 73.266048][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 73.272295][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 73.277326][ T1080] ? __kasan_check_read+0x11/0x20 [ 73.282358][ T1080] kthread+0x361/0x430 [ 73.286431][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 73.292065][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 73.297789][ T1080] ret_from_fork+0x24/0x30 [ 73.303621][ T1080] Kernel Offset: disabled [ 73.307998][ T1080] Rebooting in 86400 seconds..