Bug 1250047 (CVE-2015-5706)

Summary:	CVE-2015-5706 kernel: Use-after-free in path lookup
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	agordeev, aquini, arm-mgr, bhu, blc, dhoward, esammons, fhrbata, gansalmon, iboverma, itamar, jforbes, jkacur, joelsmith, jonathan, jross, jrusnack, jwboyer, kernel-maint, kernel-mgr, lgoncalv, lwang, madhu.chinakonda, matt, mchehab, mcressma, mguzik, mlangsdo, nmurray, pholasek, plougher, rt-maint, rvrbovsk, slong, vdronov, vgoyal, williams, wmealing
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	A use-after-free flaw was found in the Linux kernels function path_openat() in which incorrectly clears up twice (as part of path_lookupat() called by do_tmpfile()). Clearing twice can lead to a double fput(). A local, unauthenticated user could exploit this flaw to possibly cause a denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-02-12 14:14:10 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:	1250048
Bug Blocks:	1250052

Description Adam Mariš 2015-08-04 12:16:22 UTC

A flaw was found in the Linux kernels function path_openat() in which would incorrectly clear up twice (as part of path_lookupat() called by
do_tmpfile(). Doing so again can lead to double fput().  This can lead to a use-after free condition.

CVE assignment:
http://seclists.org/oss-sec/2015/q3/270

Introduced in this commit:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bb458c644a59dbba3a1fe59b27106c5e68e1c4bd

Upstream patch:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f15133df088ecadd141ea1907f2c96df67c729f0

OSS-SEC request:
http://seclists.org/oss-sec/2015/q3/371

Comment 1 Adam Mariš 2015-08-04 12:17:07 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1250048]

Comment 2 Adam Mariš 2015-08-18 09:56:13 UTC

According to this, this bug affects only 3.19 and 4.0 kernel versions:
http://seclists.org/oss-sec/2015/q3/371
https://bugzilla.suse.com/show_bug.cgi?id=940339

Comment 3 Wade Mealing 2016-02-04 08:32:09 UTC

Statement: 

This issue does not affect any shipping versions of Red Hat Enterprise Linux kernels. The patch causing the incorrect "double put" condition is not applied to any shipping kernel.

Comment 5 Wade Mealing 2016-02-12 05:56:27 UTC

Updated, now this should be a little clearer.