Bug 1679328 (CVE-2019-17342) - CVE-2019-17342 xen: xsa287: steal_page violates page_struct access discipline
Summary: CVE-2019-17342 xen: xsa287: steal_page violates page_struct access discipline
Keywords:
Status: CLOSED WONTFIX
Alias: CVE-2019-17342
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1685577
Blocks:
TreeView+ depends on / blocked
 
Reported: 2019-02-20 22:02 UTC by Pedro Sampaio
Modified: 2019-11-12 09:52 UTC (History)
13 users (show)

Fixed In Version:
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Clone Of:
Environment:
Last Closed: 2019-06-10 10:48:30 UTC


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Description Pedro Sampaio 2019-02-20 22:02:55 UTC
Xen's reference counting rules were designed to allow pages to change
owner and state without requiring a global lock. Each page has a page
structure, and a very specific set of access disciplines must be
observed to ensure that pages are freed properly, and that no writable
mappings exist for PV pagetable pages.

Unfortunately, when the XENMEM_exchange hypercall was introduced,
these access disciplines were violated, opening up several potential
race conditions.

Comment 1 Andrej Nemec 2019-03-05 14:22:19 UTC
References:

https://seclists.org/oss-sec/2019/q1/160

Comment 2 Andrej Nemec 2019-03-05 14:26:28 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1685577]


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