Bug 1823783 (CVE-2020-11739)

Summary:	CVE-2020-11739 xen: missing memory barriers in read-write unlock paths (XSA-314)
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, ailan, bhu, brdeoliv, dhoward, drjones, dvlasenk, fhrbata, hkrzesin, imammedo, jforbes, jshortt, jstancek, knoel, m.a.young, mrezanin, nmurray, pbonzini, robinlee.sysu, rvrbovsk, vkuznets, xen-maint
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	No Doc Update
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-04-16 14:22:08 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:	1823784
Bug Blocks:	1823785

Description Guilherme de Almeida Suckevicz 2020-04-14 13:50:02 UTC

The read-write unlock paths don't contain a memory barrier. On Arm, this means a processor is allowed to re-order the memory access with the preceding ones.

Reference:
https://xenbits.xen.org/xsa/advisory-314.html

Comment 1 Guilherme de Almeida Suckevicz 2020-04-14 13:50:23 UTC

Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1823784]