Bug 656206 (CVE-2010-4247)

Summary:	CVE-2010-4247 xen: request-processing loop is unbounded in blkback
Product:	[Other] Security Response	Reporter:	Eugene Teo (Security Response) <eteo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dhoward, lwang, plyons, pmatouse, rkhan, security-response-team, vkrizan, xen-maint
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-07-29 13:23:13 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:	654546, 656208
Bug Blocks:

Description Eugene Teo (Security Response) 2010-11-23 08:32:02 UTC

If the frontend pass a bad index of production request, the backend will enter an endless loop and then cause a excessive CPU consumption.

This issue has been fixed in upstream by:
changeset:   391:77f831cbb91d
user:        Keir Fraser <keir.fraser>
date:        Fri Jan 18 16:52:25 2008 +0000
summary:     blkback: Request-processing loop is unbounded and hence requires a
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/77f831cbb91d

changeset:   392:7070d34f251c
user:        Keir Fraser <keir.fraser>
date:        Mon Jan 21 11:43:31 2008 +0000
summary:     blkback/blktap: Check for kthread_should_stop() in inner loop,
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/7070d34f251c

Version-Release number of selected component (if applicable):
2.6.18-194.el5xen

How reproducible:

Steps to Reproduce:
1. build a guest kernel with the patch attached.
2. run domU with the patched kernel

Actual results:
Dom0 got hung.

Expected results:
Dom0 shouldn't be impacted by a bad guest.

Comment 4 errata-xmlrpc 2011-01-04 16:53:13 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2011:0004 https://rhn.redhat.com/errata/RHSA-2011-0004.html