Bug 1104097 (CVE-2014-3940)

Summary:	CVE-2014-3940 Kernel: missing check during hugepage migration
Product:	[Other] Security Response	Reporter:	Prasad Pandit <ppandit>
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, aquini, bhu, dhoward, esammons, fhrbata, gansalmon, iboverma, itamar, jforbes, jkacur, jkurik, jonathan, jross, jwboyer, kernel-maint, kernel-mgr, lgoncalv, lwang, madhu.chinakonda, matt, mchehab, mcressma, nobody, npajkovs, pholasek, plougher, rt-maint, rvrbovsk, toracat, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	A flaw was found in the way Linux kernel's Transparent Huge Pages (THP) implementation handled non-huge page migration. A local, unprivileged user could use this flaw to crash the kernel by migrating transparent hugepages.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-07-22 19:27:06 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:	1105037, 1105038, 1105039, 1105040, 1105041, 1105042
Bug Blocks:	1104017

Description Prasad Pandit 2014-06-03 09:34:56 UTC

Linux kernel built with the HugeTLB file system(CONFIG_HUGETLBFS
+ CONFIG_HUGETLB_PAGE) along with Non Uniform Memory Access(CONFIG_NUMA)
support is vulnerable to possible race conditions. It could occur when kernel
attempts to perform hugepage migration.

Upstream fix:
-------------
  -> https://lkml.org/lkml/2014/3/18/784  (only part 1 of the 2 patches)
  Ie: mm: add !pte_present() check on existing hugetlb_entry callbacks

Reference:
----------
  -> http://seclists.org/oss-sec/2014/q2/399

Comment 1 Prasad Pandit 2014-06-05 09:16:40 UTC

Statement:

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

Comment 4 Prasad Pandit 2014-06-05 09:27:22 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1105042]

Comment 7 Fedora Update System 2014-06-11 16:30:59 UTC

kernel-3.14.6-200.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 8 Fedora Update System 2014-06-16 23:30:02 UTC

kernel-3.14.7-100.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 9 John Kacur 2014-06-26 22:38:03 UTC

commit d4c54919ed86302094c0ca7d48a8cbd4ee753e92 upstream

Comment 10 errata-xmlrpc 2014-07-22 18:04:32 UTC

This issue has been addressed in following products:

  MRG for RHEL-6 v.2

Via RHSA-2014:0913 https://rhn.redhat.com/errata/RHSA-2014-0913.html

Comment 11 errata-xmlrpc 2015-03-05 12:15:51 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2015:0290 https://rhn.redhat.com/errata/RHSA-2015-0290.html

Comment 12 errata-xmlrpc 2015-07-22 08:07:18 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2015:1272 https://rhn.redhat.com/errata/RHSA-2015-1272.html