Bug 688579 (CVE-2011-1166)

Summary: CVE-2011-1166 kernel: xen: x86_64: fix error checking in arch_set_info_guest()
Product: [Other] Security Response Reporter: Eugene Teo (Security Response) <eteo>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dhoward, ehabkost, fhrbata, jlieskov, leiwang, lersek, lwang, mtosatti, pmatouse, rkhan, vkrizan, xen-maint
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2015-07-29 14:11:27 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 688581, 688582    
Bug Blocks:    
Attachments:
Description Flags
Local compressed copy of NetBSD kernel linked in comment 5. none

Description Eugene Teo (Security Response) 2011-03-17 12:13:11 UTC 
Cannot specify user mode execution without specifying user-mode pagetables.

The problem is that a 64-bit guest can get one of its vcpus into non-kernel mode without first providing a valid non-kernel pagetable. The iret-into-userspace path has the right checks, but just setting the context on a fresh vcpu doesn't. :(  The observed failure mode is usually a hard lockup of the host. This affects 64-bit version of kernel-xen.

Upstream commit:
http://xenbits.xen.org/hg/staging/xen-unstable.hg/rev/c79aae866ad8

Reference:
https://bugzilla.novell.com/show_bug.cgi?id=679344
Comment 15 errata-xmlrpc 2011-05-31 14:07:06 UTC 
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2011:0833 https://rhn.redhat.com/errata/RHSA-2011-0833.html