Bug 1415733 (CVE-2017-5546)

Summary:	CVE-2017-5546 kernel: SLAB freelist randomization produces duplicate entries
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, bhu, dhoward, esammons, fhrbata, gansalmon, iboverma, ichavero, itamar, jforbes, jkacur, jkastner, jonathan, jross, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, lwang, madhu.chinakonda, matt, mchehab, mcressma, mguzik, nmurray, pholasek, plougher, rt-maint, rvrbovsk, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 4.9.5	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-01-24 15:01:28 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:

Description Adam Mariš 2017-01-23 15:10:11 UTC

A bug in freelist randomization code was found resulting into freelist containing duplicate entries when high random number is used. This will result in different allocations sharing the same chunk which can cause odd behaviours and crashes.

This affects kernel versions >= 4.8 when CONFIG_SLAB_FREELIST_RANDOM is enabled.

Upstream patch:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c4e490cf148e85ead0d1b1c2caaba833f1d5b29f

CVE assignment:

http://seclists.org/oss-sec/2017/q1/161

Comment 1 Justin M. Forbes 2017-01-23 22:00:17 UTC

This was fixed in stable update 4.9.5 which is currently on all supported Fedora releases

Comment 2 Adam Mariš 2017-01-24 15:01:28 UTC

(In reply to Justin M. Forbes from comment #1)
> This was fixed in stable update 4.9.5 which is currently on all supported
> Fedora releases

Thanks, marking as not affected then.