[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 52.754034][ T27] audit: type=1800 audit(1571787492.000:25): pid=8451 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 52.775309][ T27] audit: type=1800 audit(1571787492.000:26): pid=8451 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 52.796945][ T27] audit: type=1800 audit(1571787492.000:27): pid=8451 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 '10.128.0.107' (ECDSA) to the list of known hosts. 2019/10/22 23:38:20 fuzzer started 2019/10/22 23:38:22 dialing manager at 10.128.0.26:45989 2019/10/22 23:38:22 syscalls: 2525 2019/10/22 23:38:22 code coverage: enabled 2019/10/22 23:38:22 comparison tracing: enabled 2019/10/22 23:38:22 extra coverage: extra coverage is not supported by the kernel 2019/10/22 23:38:22 setuid sandbox: enabled 2019/10/22 23:38:22 namespace sandbox: enabled 2019/10/22 23:38:22 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 23:38:22 fault injection: enabled 2019/10/22 23:38:22 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 23:38:22 net packet injection: enabled 2019/10/22 23:38:22 net device setup: enabled 2019/10/22 23:38:22 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 71.750845][ T1079] ------------[ cut here ]------------ [ 71.756391][ T1079] WARNING: CPU: 0 PID: 1079 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 71.765432][ T1079] Kernel panic - not syncing: panic_on_warn set ... [ 71.772055][ T1079] CPU: 0 PID: 1079 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 71.780799][ T1079] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.790862][ T1079] Call Trace: [ 71.794159][ T1079] dump_stack+0x172/0x1f0 [ 71.798492][ T1079] ? collapse_file+0x1ef0/0x4170 [ 71.803436][ T1079] panic+0x2e3/0x75c [ 71.807334][ T1079] ? add_taint.cold+0x16/0x16 [ 71.812023][ T1079] ? printk+0xba/0xed [ 71.816010][ T1079] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 71.821473][ T1079] ? __warn.cold+0x14/0x35 [ 71.825894][ T1079] ? __warn+0xd9/0x1d0 [ 71.829973][ T1079] ? collapse_file+0x1f9d/0x4170 [ 71.834912][ T1079] __warn.cold+0x2f/0x35 [ 71.839161][ T1079] ? report_bug.cold+0x63/0xb2 [ 71.843931][ T1079] ? collapse_file+0x1f9d/0x4170 [ 71.849745][ T1079] report_bug+0x289/0x300 [ 71.854084][ T1079] do_error_trap+0x11b/0x200 [ 71.858681][ T1079] do_invalid_op+0x37/0x50 [ 71.863106][ T1079] ? collapse_file+0x1f9d/0x4170 [ 71.868051][ T1079] invalid_op+0x23/0x30 [ 71.872218][ T1079] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 71.877764][ 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 [ 71.897485][ T1079] RSP: 0018:ffff8880a7d6fad0 EFLAGS: 00010293 [ 71.903571][ T1079] RAX: ffff8880a7ed6400 RBX: ffff8880a7d6fc88 RCX: ffffffff81b2b688 [ 71.911550][ T1079] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 71.919530][ T1079] RBP: ffff8880a7d6fcb0 R08: ffff8880a7ed6400 R09: fffff9400005c951 [ 71.927512][ T1079] R10: fffff9400005c950 R11: ffffea00002e4a87 R12: 0000000000000001 [ 71.935497][ T1079] R13: ffffea0002394448 R14: 0000000000000000 R15: ffffea0002220000 [ 71.943528][ T1079] ? collapse_file+0x1c78/0x4170 [ 71.948486][ T1079] ? collapse_file+0x1f9d/0x4170 [ 71.953553][ T1079] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 71.959730][ T1079] ? khugepaged+0x21d0/0x4360 [ 71.964426][ T1079] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 71.972522][ T1079] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 71.978250][ T1079] ? khugepaged_find_target_node+0x142/0x180 [ 71.984243][ T1079] khugepaged+0x2da9/0x4360 [ 71.988762][ T1079] ? __kasan_check_read+0x11/0x20 [ 71.993885][ T1079] ? __lock_acquire+0x16f2/0x4a00 [ 71.998924][ T1079] ? _raw_spin_unlock_irq+0x23/0x80 [ 72.004150][ T1079] ? finish_task_switch+0x147/0x750 [ 72.009357][ T1079] ? _raw_spin_unlock_irq+0x23/0x80 [ 72.014571][ T1079] ? lockdep_hardirqs_on+0x421/0x5e0 [ 72.019882][ T1079] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 72.025544][ T1079] ? lock_downgrade+0x920/0x920 [ 72.030409][ T1079] ? finish_wait+0x260/0x260 [ 72.035022][ T1079] ? lockdep_hardirqs_on+0x421/0x5e0 [ 72.040320][ T1079] ? trace_hardirqs_on+0x67/0x240 [ 72.045387][ T1079] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 72.051662][ T1079] ? __kthread_parkme+0x108/0x1c0 [ 72.056693][ T1079] ? __kasan_check_read+0x11/0x20 [ 72.061731][ T1079] kthread+0x361/0x430 [ 72.065810][ T1079] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 72.071449][ T1079] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 72.077180][ T1079] ret_from_fork+0x24/0x30 [ 72.083188][ T1079] Kernel Offset: disabled [ 72.087585][ T1079] Rebooting in 86400 seconds..