Bug 1070618 (CVE-2014-0100)

Summary:	CVE-2014-0100 kernel: net: inet frag code race condition leading to user-after-free
Product:	[Other] Security Response	Reporter:	Petr Matousek <pmatouse>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	ASSIGNED ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	aquini, kernel-mgr, nobody, npajkovs, peterm, rkhan
Target Milestone:	---	Keywords:	Reopened, Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-02-27 09:27:32 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:	1070620, 1070711, 1072026
Bug Blocks:	1070640

Description Petr Matousek 2014-02-27 09:22:49 UTC

Description of the problem:

A very subtle race condition between inet_frag_evictor,
inet_frag_intern and the IPv4/6 frag_queue and expire functions (basically
the users of inet_frag_kill/inet_frag_put) was found.

What happens is that after a fragment has been added to the hash chain but
before it's been added to the lru_list (inet_frag_lru_add), it may get
deleted (either by an expired timer if the system load is high or the
timer sufficiently low, or by the fraq_queue function for different
reasons) before it's added to the lru_list, then after it gets added
it's a matter of time for the evictor to get to a piece of memory which
has been freed leading to a number of different bugs depending on what's
left there.

Introduced by:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3ef0eb0d

Acknowledgements:

This issue was discovered by Nikolay Aleksandrov of Red Hat.

Comment 1 Petr Matousek 2014-02-27 09:27:32 UTC

Statement:

This issue did not affect the versions of Linux kernel package as shipped with Red Hat Enterprise Linux 5 and 6 as they did not backport the commit that introduced this issue.

Comment 5 Petr Matousek 2014-03-03 17:03:50 UTC

Upstream patch submission:

http://patchwork.ozlabs.org/patch/325844/

Comment 6 Petr Matousek 2014-03-03 17:30:42 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1072026]

Comment 7 Fedora Update System 2014-03-06 08:09:56 UTC

kernel-3.13.5-202.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 2014-03-09 04:38:38 UTC

kernel-3.13.5-103.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 Petr Matousek 2014-05-05 15:07:54 UTC

Upstream patch:

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=24b9bf43e93e0edd89072da51cf1fab95fc69dec

Comment 10 errata-xmlrpc 2014-05-27 16:27:21 UTC

This issue has been addressed in following products:

  MRG for RHEL-6 v.2

Via RHSA-2014:0557 https://rhn.redhat.com/errata/RHSA-2014-0557.html