Bug 1992264 (CVE-2021-38198)

Summary:	CVE-2021-38198 kernel: arch/x86/kvm/mmu/paging_tmpl.h incorrectly computes the access permissions of a shadow page
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bhu, brdeoliv, bskeggs, chwhite, crwood, dhoward, dvlasenk, eshatokhin, fhrbata, fpacheco, hdegoede, hkrzesin, jarod, jarodwilson, jeremy, jforbes, jlelli, jonathan, josef, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, nmurray, ptalbert, qzhao, rvrbovsk, steved, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	Linux kernel 5.13-rc6	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the Linux kernel, where it incorrectly computes the access permissions of a shadow page. This issue leads to a missing guest protection page fault.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-12-15 11:26:26 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1992265, 1993227, 1993228, 1993229, 1993230, 1993231
Bug Blocks:	1992266

Description Guilherme de Almeida Suckevicz 2021-08-10 20:20:47 UTC

arch/x86/kvm/mmu/paging_tmpl.h in the Linux kernel before 5.12.11 incorrectly computes the access permissions of a shadow page, leading to a missing guest protection page fault.

Reference and upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b1bd5cba3306691c771d558e94baa73e8b0b96b7

Comment 1 Guilherme de Almeida Suckevicz 2021-08-10 20:21:19 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1992265]

Comment 2 Justin M. Forbes 2021-08-11 19:55:48 UTC

This was fixed for Fedora with the 5.12.11 stable kernel updates.