Bug 912898 (CVE-2013-0309)

Summary:	CVE-2013-0309 kernel: mm: thp: pmd_present and PROT_NONE local DoS
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:	agordeev, anton, bhu, davej, dhoward, fhrbata, gansalmon, iboverma, itamar, jforbes, jkacur, jneedle, jonathan, jrusnack, jwboyer, kernel-maint, kernel-mgr, lgoncalv, lwang, madhu.chinakonda, mcressma, npajkovs, plougher, rt-maint, rvrbovsk, sforsber, 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:	2013-05-08 18:41:27 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:	858385
Bug Blocks:

Description Petr Matousek 2013-02-19 23:53:15 UTC

Most VM places are using pmd_none but a few are still using pmd_present. The meaning is about the same for the pmd. However pmd_present would return the wrong value on PROT_NONE ranges. When the code using pmd_present gets a false negative, the kernel will crash. An unprivileged local user could use this flaw to crash the system.

Upstream fix:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=027ef6c8

Comment 1 Petr Matousek 2013-02-20 00:49:02 UTC

Statement:

This issue did affect the version of Linux kernel as shipped with Red Hat Enterprise Linux 6.

This issue did not affect the version of Linux kernel as shipped with Red Hat Enterprise Linux 5 and Red Hat Enterprise MRG 2.

Comment 2 errata-xmlrpc 2013-02-21 07:02:34 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2013:0496 https://rhn.redhat.com/errata/RHSA-2013-0496.html