Bug 1360968 (CVE-2015-8952)

Summary:	CVE-2015-8952 kernel: mbcache code subject to softlockup DOS in cache management
Product:	[Other] Security Response	Reporter:	Wade Mealing <wmealing>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	aquini, bhu, dhoward, fhrbata, iboverma, jkacur, joelsmith, jross, kernel-mgr, kstutsma, lgoncalv, matt, mcressma, nmurray, plougher, rvrbovsk, security-response-team, slawomir, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A design flaw was found in the file extended attribute handling of the Linux kernel's handling of cached attributes. Too many entries in the cache cause a soft lockup while attempting to iterate the cache and access relevant locks.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 02:56:42 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:	1368919
Bug Blocks:	1352636

Description Wade Mealing 2016-07-28 05:10:20 UTC

A design flaw was found in the file extended attribute handling of the linux kernels handling of cached attributes.  Too many entries in the cache cause a soft lockup while attempting to iterate the cache and access relevant locks.

Upstream has replaced the mbcache code with an updated version which was not a patch but a clear-cut reimplentation of the code.

Upstream discussion:
https://lwn.net/Articles/668718/

Bugzilla kernel submission:
https://bugzilla.kernel.org/show_bug.cgi?id=107301

Probable fix:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=be0726d33cb8f411945884664924bed3cb8c70ee

Comment 2 Wade Mealing 2016-07-28 06:27:34 UTC

Acknowledgements:

Red Hat would like to thank Laurent Guerby for bringing this to our attention.

Comment 3 Wade Mealing 2016-08-18 03:09:32 UTC

Statement:

This issue does not affect any shiping version of Red Hat Enterprise Linux.

Comment 4 Prasad Pandit 2016-08-22 06:35:33 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1368919]

Comment 6 Andrej Nemec 2016-08-26 08:00:13 UTC

CVE assignment:

http://seclists.org/oss-sec/2016/q3/378