Bug 1102254 (CVE-2014-3967, CVE-2014-3968)

Summary: CVE-2014-3967 CVE-2014-3968 xen: Vulnerabilities in HVM MSI injection (XSA-96)
Product: [Other] Security Response Reporter: Petr Matousek <pmatouse>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: drjones, imammedo, pbonzini, rkrcmar, security-response-team
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: 2014-05-28 15:50:49 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: 1104583    
Bug Blocks: 1102255    

Description Petr Matousek 2014-05-28 15:49:29 UTC 
The implementation of the HVM control operation HVMOP_inject_msi, while
checking whether a particular IRQ was already set up in the necessary
way, fails to properly check all respective conditions. In particular
it doesn't check the returned pointer for being non-NULL before de-
referencing it.

Furthermore that same code also handles certain errors by logging
messages, without (under default settings) at least making these
messages subject to rate limiting.

The NULL pointer de-reference would lead to a host crash, and hence a
denial of service would result.

The spamming of the hypervisor log could similarly lead to a denial of
service.

Acknowledgements:

Red Hat would like to thank the Xen project for reporting this issue.
Comment 2 Petr Matousek 2014-05-28 15:50:49 UTC 
Statement:

Not vulnerable.

This issue did not affect the versions of the kernel-xen package as
shipped with Red Hat Enterprise Linux 5.

This issue did not affect Red Hat Enterprise Linux 6 and Red Hat
Enterprise MRG 2 as we did not have support for Xen hypervisor.
Comment 3 Petr Matousek 2014-06-04 09:09:54 UTC 
External references:

http://www.openwall.com/lists/oss-security/2014/06/03/9
Comment 4 Petr Matousek 2014-06-04 09:10:14 UTC 
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1104583]