Bug 837502 (CVE-2012-3375)

Summary:	CVE-2012-3375 kernel: epoll: can leak file descriptors when returning -ELOOP
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, djorm, fhrbata, gansalmon, itamar, jforbes, jkacur, jonathan, jwboyer, kernel-maint, kernel-mgr, lgoncalv, lwang, madhu.chinakonda, mjc, plougher, rt-maint, 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:	2013-08-24 13:53:16 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:	817131, 817140, 829670, 837503, 837504, 837505, 837506, 837507, 837509
Bug Blocks:	717854

Description Petr Matousek 2012-07-04 07:09:04 UTC

An epoll_ctl(,EPOLL_CTL_ADD,,) operation can return '-ELOOP' to prevent circular epoll dependencies from being created.  However, in that case we do not properly clear the 'tfile_check_list'.

An unprivileged local user could use this flaw to crash the system.

This is a regression introduced via the CVE-2011-1083 (bug #681578) fix (commit 28d82dc1c4edbc352129f97f4ca22624d1fe61de):
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=28d82dc1c4edbc352129f97f4ca22624d1fe61de

Upstream fix:
13d518074a952d33d47c428419693f63389547e9
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=13d518074a952d33d47c428419693f63389547e9

References:
https://lkml.org/lkml/2012/3/27/65
https://lkml.org/lkml/2012/4/17/247

Comment 3 Petr Matousek 2012-07-04 07:13:01 UTC

Created kernel tracking bugs for this issue

Affects: fedora-all [bug 837506]

Comment 5 Vincent Danen 2012-07-04 17:14:33 UTC

Assigned CVE-2012-3375 as per:

http://www.openwall.com/lists/oss-security/2012/07/04/2

Comment 6 Petr Matousek 2012-07-06 18:10:33 UTC

Statement:

This issue did not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 6, since updates fixing CVE-2011-1083 contained a corrected patch that did not introduce this regression. 

This has been addressed in Red Hat Enterprise Linux 5 via https://rhn.redhat.com/errata/RHSA-2012-1061.html, and Red Hat Enterprise Linux Red Hat Enterprise MRG 2 via https://rhn.redhat.com/errata/RHSA-2012-1150.html

Comment 7 errata-xmlrpc 2012-07-10 11:35:14 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2012:1061 https://rhn.redhat.com/errata/RHSA-2012-1061.html

Comment 8 errata-xmlrpc 2012-08-08 16:35:26 UTC

This issue has been addressed in following products:

  MRG for RHEL-6 v.2

Via RHSA-2012:1150 https://rhn.redhat.com/errata/RHSA-2012-1150.html