Bug 722557 (CVE-2011-2695)

Summary:	CVE-2011-2695 kernel: ext4: kernel panic when writing data to the last block of sparse file
Product:	[Other] Security Response	Reporter:	Petr Matousek <pmatouse>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	arozansk, bhu, dhoward, fhrbata, jkacur, kernel-mgr, kmcmartin, lgoncalv, lwang, nobody, plougher, rt-maint, rwheeler, sforsber, tcallawa, vgoyal, williams
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 12:49:01 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:	722562, 722563, 722564, 722568, 722569
Bug Blocks:

Description Petr Matousek 2011-07-15 16:20:18 UTC

If an extent exists which includes the block right before the maximum file offset, and the block for the maximum file offset is written, the kernel panics. For 4KB block size, the problem only occurs on x86_64 architecture. For 1KB or 2KB block size, the problem occurs on both i386 and x86_64.

Local unprivileged users can use this flaw to crash the system when ext4 filesystem is in use.

Upstream fix:
http://git.kernel.org/linus/f17722f917b2f21497deb6edc62fb1683daa08e6

References:
http://www.spinics.net/lists/linux-ext4/msg25697.html

Comment 4 Petr Matousek 2011-07-15 16:52:58 UTC

Statement:

This has been addressed in Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG via https://rhn.redhat.com/errata/RHSA-2011-1386.html,  https://rhn.redhat.com/errata/RHSA-2011-1189.html, and https://rhn.redhat.com/errata/RHSA-2011-1253.html. This issue did not affect the versions of Linux kernel as shipped with Red Hat Enterprise Linux 4 as it did not include support for EXT4 filesystem.

Comment 6 errata-xmlrpc 2011-08-23 14:42:11 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2011:1189 https://rhn.redhat.com/errata/RHSA-2011-1189.html

Comment 7 errata-xmlrpc 2011-09-12 19:44:44 UTC

This issue has been addressed in following products:

  MRG for RHEL-6 v.2

Via RHSA-2011:1253 https://rhn.redhat.com/errata/RHSA-2011-1253.html

Comment 8 errata-xmlrpc 2011-10-20 17:28:23 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2011:1386 https://rhn.redhat.com/errata/RHSA-2011-1386.html

Comment 9 Eugene Teo (Security Response) 2012-04-10 00:59:53 UTC

This issue has been addressed in rhel-6.1.z via RHSA-2011:1189 https://rhn.redhat.com/errata/RHSA-2011-1189.html