Bug 1166913 (CVE-2014-9030, xsa113)

Summary: CVE-2014-9030 kernel: xen: Guest effectable page reference leak in MMU_MACHPHYS_UPDATE handling
Product: [Other] Security Response Reporter: Vincent Danen <vdanen>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED WONTFIX QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: agordeev, dhoward, drjones, imammedo, jforbes, jrusnack, kraxel, lwang, m.a.young, mguzik, mrezanin, nmurray, pbonzini, pholasek, plougher, pmatouse, rkrcmar, rvrbovsk, virt-maint, vkuznets, xen-maint
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: 2014-11-23 18:47:28 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:
Bug Depends On: 1166914    
Bug Blocks: 1166915    
Attachments:
Description Flags
upstream patch none

Description Vincent Danen 2014-11-21 23:26:26 UTC 
An error handling path in the processing of MMU_MACHPHYS_UPDATE failed
to drop a page reference which was acquired in an earlier processing
step.

Malicious or buggy stub domain kernels or tool stacks otherwise living
outside of Domain0 can mount a denial of service attack which, if
successful, can affect the whole system.

Only domains controlling HVM guests can exploit this vulnerability.
(This includes domains providing hardware emulation services to HVM
guests.)

Xen versions from at least 3.2.x onwards are vulnerable on x86 systems.
Older versions have not been inspected.  ARM systems are not vulnerable.

This vulnerability is only applicable to Xen systems using stub domains
or other forms of disaggregation of control domains for HVM guests.


Acknowledgements:

Red Hat would like to thank the Xen project for reporting this issue.


External References:

http://xenbits.xen.org/xsa/advisory-113.html
Comment 1 Vincent Danen 2014-11-21 23:26:49 UTC 
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1166914]
Comment 2 Vincent Danen 2014-11-21 23:33:48 UTC 
Created attachment 960013 [details]
upstream patch
Comment 3 Petr Matousek 2014-11-23 18:47:28 UTC 
Statement:

Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. This has been rated as having Low security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.