Bug 1499815 (CVE-2017-15597, xsa236) - CVE-2017-15597 xsa236 xen: pin count / page reference race in grant table code (XSA-236)
Summary: CVE-2017-15597 xsa236 xen: pin count / page reference race in grant table cod...
Keywords:
Status: CLOSED WONTFIX
Alias: CVE-2017-15597, xsa236
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1506693
Blocks:
TreeView+ depends on / blocked
 
Reported: 2017-10-09 12:51 UTC by Adam Mariš
Modified: 2021-02-17 01:26 UTC (History)
13 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
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Clone Of:
Environment:
Last Closed: 2019-06-08 03:27:01 UTC


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Description Adam Mariš 2017-10-09 12:51:06 UTC
ISSUE DESCRIPTION
=================

Grant copying code made an implication that any grant pin would be
accompanied by a suitable page reference.  Other portions of code,
however, did not match up with that assumption.  When such a grant
copy operation is being done on a grant of a dying domain, the
assumption turns out wrong.

IMPACT
======

A malicious guest administrator can cause can cause hypervisor memory
corruption, most likely resulting in host crash and a Denial of
Service.  Privilege escalation and information leaks cannot be ruled
out.

VULNERABLE SYSTEMS
==================

Xen versions from 4.2 onwards are vulnerable.  Xen versions 4.1 and
earlier are not vulnerable.

Both x86 and ARM are vulnerable, and on x86 both PV and HVM guests can
trigger the vulnerability.

MITIGATION
==========

Running only guests without para-virtual drivers, and known not to
issue grant table operations can avoid the vulnerability.

External References:

http://xenbits.xen.org/xsa/advisory-236.html

Comment 1 Andrej Nemec 2017-10-26 15:02:06 UTC
Public via:

http://seclists.org/oss-sec/2017/q4/131

Comment 2 Andrej Nemec 2017-10-26 15:02:18 UTC
Acknowledgments:

Name: the Xen project
Upstream: Pawel Wieczorkiewicz (Amazon)

Comment 3 Andrej Nemec 2017-10-26 15:03:12 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1506693]


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