Bug 1905658 (CVE-2020-29568)

Summary:	CVE-2020-29568 xen: frontends can trigger OOM in backends by update a watched path (XSA-349)
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	jforbes, m.a.young, robinlee.sysu, security-response-team
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-12-15 22:20:01 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:	1908084
Bug Blocks:	1903644

Description Guilherme de Almeida Suckevicz 2020-12-08 18:47:29 UTC

Some OSes (such as Linux, FreeBSD, NetBSD) are processing watch events
using a single thread.  If the events are received faster than the thread
is able to handle, they will get queued.

As the queue is unbound, a guest may be able to trigger a OOM in
the backend.

Comment 1 Guilherme de Almeida Suckevicz 2020-12-15 19:55:40 UTC

External References:

https://www.openwall.com/lists/oss-security/2020/12/15/10

Comment 2 Guilherme de Almeida Suckevicz 2020-12-15 19:55:52 UTC

Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1908084]

Comment 3 Product Security DevOps Team 2020-12-15 22:20:01 UTC

This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.

Comment 4 Justin M. Forbes 2021-03-04 22:01:22 UTC

This was fixed for Fedora with the 5.10.4 stable kernel updates.