[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 56.728502][ T27] audit: type=1800 audit(1571795406.550:25): pid=8387 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 56.775593][ T27] audit: type=1800 audit(1571795406.550:26): pid=8387 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 56.808403][ T27] audit: type=1800 audit(1571795406.560:27): pid=8387 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 '10.128.0.96' (ECDSA) to the list of known hosts. 2019/10/23 01:50:17 fuzzer started 2019/10/23 01:50:19 dialing manager at 10.128.0.26:45989 2019/10/23 01:50:19 syscalls: 2525 2019/10/23 01:50:19 code coverage: enabled 2019/10/23 01:50:19 comparison tracing: enabled 2019/10/23 01:50:19 extra coverage: extra coverage is not supported by the kernel 2019/10/23 01:50:19 setuid sandbox: enabled 2019/10/23 01:50:19 namespace sandbox: enabled 2019/10/23 01:50:19 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 01:50:19 fault injection: enabled 2019/10/23 01:50:19 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 01:50:19 net packet injection: enabled 2019/10/23 01:50:19 net device setup: enabled 2019/10/23 01:50:19 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 78.134216][ T1080] ------------[ cut here ]------------ [ 78.139748][ T1080] WARNING: CPU: 1 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 78.148787][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 78.155364][ T1080] CPU: 1 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 78.163922][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 78.173950][ T1080] Call Trace: [ 78.177266][ T1080] dump_stack+0x172/0x1f0 [ 78.181574][ T1080] ? collapse_file+0x1ef0/0x4170 [ 78.186486][ T1080] panic+0x2e3/0x75c [ 78.190356][ T1080] ? add_taint.cold+0x16/0x16 [ 78.195043][ T1080] ? printk+0xba/0xed [ 78.199001][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 78.204472][ T1080] ? __warn.cold+0x14/0x35 [ 78.208861][ T1080] ? __warn+0xd9/0x1d0 [ 78.212939][ T1080] ? collapse_file+0x1f9d/0x4170 [ 78.217850][ T1080] __warn.cold+0x2f/0x35 [ 78.222108][ T1080] ? report_bug.cold+0x63/0xb2 [ 78.226863][ T1080] ? collapse_file+0x1f9d/0x4170 [ 78.231779][ T1080] report_bug+0x289/0x300 [ 78.236088][ T1080] do_error_trap+0x11b/0x200 [ 78.240664][ T1080] do_invalid_op+0x37/0x50 [ 78.245056][ T1080] ? collapse_file+0x1f9d/0x4170 [ 78.249969][ T1080] invalid_op+0x23/0x30 [ 78.254112][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 78.259644][ 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 [ 78.279226][ T1080] RSP: 0018:ffff8880a7eefad0 EFLAGS: 00010293 [ 78.285270][ T1080] RAX: ffff8880a7d9a440 RBX: ffff8880a7eefc88 RCX: ffffffff81b2b688 [ 78.293218][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 78.301168][ T1080] RBP: ffff8880a7eefcb0 R08: ffff8880a7d9a440 R09: fffff94000490891 [ 78.309115][ T1080] R10: fffff94000490890 R11: ffffea0002484487 R12: 0000000000000001 [ 78.317064][ T1080] R13: ffffea0002322788 R14: 0000000000000000 R15: ffffea0002200000 [ 78.325052][ T1080] ? collapse_file+0x1c78/0x4170 [ 78.329962][ T1080] ? collapse_file+0x1f9d/0x4170 [ 78.334878][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 78.341019][ T1080] ? khugepaged+0x21d0/0x4360 [ 78.345675][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 78.353723][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 78.359421][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 78.365377][ T1080] khugepaged+0x2da9/0x4360 [ 78.369878][ T1080] ? __kasan_check_read+0x11/0x20 [ 78.374890][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 78.379900][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 78.385077][ T1080] ? finish_task_switch+0x147/0x750 [ 78.390276][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 78.395455][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 78.400735][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 78.406363][ T1080] ? lock_downgrade+0x920/0x920 [ 78.411204][ T1080] ? finish_wait+0x260/0x260 [ 78.415795][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 78.421065][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 78.426072][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 78.432291][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 78.437289][ T1080] ? __kasan_check_read+0x11/0x20 [ 78.442293][ T1080] kthread+0x361/0x430 [ 78.446361][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 78.451983][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 78.457733][ T1080] ret_from_fork+0x24/0x30 [ 78.463677][ T1080] Kernel Offset: disabled [ 78.468058][ T1080] Rebooting in 86400 seconds..