Bug 216364

Summary:	[Kernel IBT][kvm] There was "Missing ENDBR" in kvm when syzkaller tests
Product:	Virtualization	Reporter:	xupengfe (pengfei.xu)
Component:	kvm	Assignee:	virtualization_kvm
Status:	RESOLVED CODE_FIX
Severity:	normal	CC:	heng.su, pengfei.xu
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	v5.19 mainline kernel	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	Host_kernel_missing_endbr_from_kvm Fixed_patch_from_Peter_Z

Description xupengfe 2022-08-15 06:25:25 UTC

Created attachment 301563 [details]
Host_kernel_missing_endbr_from_kvm

I used syzkaller and found the "Missing ENDBR: andw_ax_dx+0x0/0x10 [kvm]" BUG in the host.

Platform: ADL-P/TGL-U or TGL-H

Host Kernel:   v5.19 mainline kernel with kernel IBT
Guest kernel: v5.19 mainline kernel without kernel IBT, moved kconfig "CONFIG_X86_KERNEL_IBT=y".

Host kernel enabled kernel IBT by adding the KCONFIG "CONFIG_X86_KERNEL_IBT=y".

In syzkaller guest kernel, guest didn't enable kernel IBT and used 5.19 mainline kernel also.

After launched the syzkaller test about 2 hours.

There was  "Missing ENDBR: andw_ax_dx+0x0/0x10 [kvm]" info generated in host kernel.

[    0.000000] Linux version 5.19.0-m2 (root@xpf.sh.intel.com) (gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-10), GNU ld version 2.36.1-2.el8) #1 SMP PREEMPT_DYNAMIC Mon Aug 1 14:23:55 CST 2022
[ 5048.057266] traps: Missing ENDBR: andw_ax_dx+0x0/0x10 [kvm]
[ 5048.057440] ------------[ cut here ]------------
[ 5048.057457] kernel BUG at arch/x86/kernel/traps.c:253!

Host dmesg was in attached.


Thanks!

Comment 1 xupengfe 2022-08-17 11:05:13 UTC

Created attachment 301591 [details]
Fixed_patch_from_Peter_Z

Comment 2 xupengfe 2022-08-17 11:05:50 UTC

Peter Zijlstra <peterz@infradead.org> gave the fixed patch.
I will have a try to verify the fixed patch.

Thanks!

Comment 3 xupengfe 2022-08-19 05:57:24 UTC

This issue was fixed by the patches in below link:

https://lore.kernel.org/lkml/64365019-57dc-b449-8178-30428e09adf8@redhat.com/

 

Verified it's could not be reproduced with syzkaller test for more than 4 hours on TGL-H and ADL-P.

Could close this issue.
Thanks!

Comment 4 xupengfe 2022-08-19 06:09:17 UTC

This issue was fixed by the patches in below link:

https://lore.kernel.org/lkml/64365019-57dc-b449-8178-30428e09adf8@redhat.com/

 

Verified it could not be reproduced with syzkaller test for more than 4 hours on TGL-H and ADL-P.

Could close this issue.
Thanks!