[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 57.967885][ T27] audit: type=1800 audit(1571792677.310:25): pid=8449 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 58.008291][ T27] audit: type=1800 audit(1571792677.320:26): pid=8449 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 58.045860][ T27] audit: type=1800 audit(1571792677.320:27): pid=8449 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 '10.128.0.157' (ECDSA) to the list of known hosts. 2019/10/23 01:04:46 fuzzer started syzkaller login: [ 67.218763][ T1081] ------------[ cut here ]------------ [ 67.224284][ T1081] WARNING: CPU: 1 PID: 1081 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 67.233303][ T1081] Kernel panic - not syncing: panic_on_warn set ... [ 67.239898][ T1081] CPU: 1 PID: 1081 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 67.248484][ T1081] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.258572][ T1081] Call Trace: [ 67.261863][ T1081] dump_stack+0x172/0x1f0 [ 67.266185][ T1081] ? collapse_file+0x1ef0/0x4170 [ 67.271121][ T1081] panic+0x2e3/0x75c [ 67.275022][ T1081] ? add_taint.cold+0x16/0x16 [ 67.279710][ T1081] ? printk+0xba/0xed [ 67.283692][ T1081] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 67.289159][ T1081] ? __warn.cold+0x14/0x35 [ 67.293576][ T1081] ? __warn+0xd9/0x1d0 [ 67.297655][ T1081] ? collapse_file+0x1f9d/0x4170 [ 67.302600][ T1081] __warn.cold+0x2f/0x35 [ 67.306848][ T1081] ? report_bug.cold+0x63/0xb2 [ 67.311620][ T1081] ? collapse_file+0x1f9d/0x4170 [ 67.316627][ T1081] report_bug+0x289/0x300 [ 67.320967][ T1081] do_error_trap+0x11b/0x200 [ 67.325570][ T1081] do_invalid_op+0x37/0x50 [ 67.329995][ T1081] ? collapse_file+0x1f9d/0x4170 [ 67.334923][ T1081] invalid_op+0x23/0x30 [ 67.339072][ T1081] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 67.344610][ T1081] 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 [ 67.364552][ T1081] RSP: 0018:ffff8880a7d17ad0 EFLAGS: 00010293 [ 67.370810][ T1081] RAX: ffff8880a7dd2480 RBX: ffff8880a7d17c88 RCX: ffffffff81b2b688 [ 67.378767][ T1081] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 67.386756][ T1081] RBP: ffff8880a7d17cb0 R08: ffff8880a7dd2480 R09: fffff94000464001 [ 67.394713][ T1081] R10: fffff94000464000 R11: ffffea0002320007 R12: 0000000000000001 [ 67.402675][ T1081] R13: ffffea00023473c8 R14: 0000000000000000 R15: ffffea00023f0000 [ 67.410655][ T1081] ? collapse_file+0x1c78/0x4170 [ 67.415572][ T1081] ? collapse_file+0x1f9d/0x4170 [ 67.420507][ T1081] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 67.426684][ T1081] ? khugepaged+0x21d0/0x4360 [ 67.431361][ T1081] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 67.439432][ T1081] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 67.445139][ T1081] ? khugepaged_find_target_node+0x142/0x180 [ 67.451113][ T1081] khugepaged+0x2da9/0x4360 [ 67.455600][ T1081] ? __kasan_check_read+0x11/0x20 [ 67.460609][ T1081] ? __lock_acquire+0x16f2/0x4a00 [ 67.466051][ T1081] ? _raw_spin_unlock_irq+0x23/0x80 [ 67.471228][ T1081] ? finish_task_switch+0x147/0x750 [ 67.476416][ T1081] ? _raw_spin_unlock_irq+0x23/0x80 [ 67.481602][ T1081] ? lockdep_hardirqs_on+0x421/0x5e0 [ 67.486877][ T1081] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 67.492492][ T1081] ? lock_downgrade+0x920/0x920 [ 67.497328][ T1081] ? finish_wait+0x260/0x260 [ 67.501902][ T1081] ? lockdep_hardirqs_on+0x421/0x5e0 [ 67.507200][ T1081] ? trace_hardirqs_on+0x67/0x240 [ 67.512223][ T1081] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 67.518454][ T1081] ? __kthread_parkme+0x108/0x1c0 [ 67.523465][ T1081] ? __kasan_check_read+0x11/0x20 [ 67.528499][ T1081] kthread+0x361/0x430 [ 67.532559][ T1081] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 67.538186][ T1081] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 67.543908][ T1081] ret_from_fork+0x24/0x30 [ 67.549725][ T1081] Kernel Offset: disabled [ 67.554096][ T1081] Rebooting in 86400 seconds..