Bug 1035811 (CVE-2013-6400) - CVE-2013-6400 xen: IOMMU TLB flushing may be inadvertently suppressed
Summary: CVE-2013-6400 xen: IOMMU TLB flushing may be inadvertently suppressed
Alias: CVE-2013-6400
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1040024
Blocks: 1035806
TreeView+ depends on / blocked
Reported: 2013-11-28 14:26 UTC by Petr Matousek
Modified: 2021-02-17 07:08 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2013-11-28 14:28:53 UTC

Attachments (Terms of Use)

Description Petr Matousek 2013-11-28 14:26:21 UTC
An internal flag is used to temporarily suppress IOMMU TLB flushes, in
order to consolidate multiple single page flushes into one wider
flush.  This flag is not cleared again, on certain error paths.  This
can result in TLB flushes not happening when they are needed.
Retaining stale TLB entries could allow guests access to memory that
ought to have been revoked, or grant greater access than intended.

Malicious guest administrators might be able to cause host-wide denial of
service, or escalate their privilege to that of the host.


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

Comment 2 Petr Matousek 2013-11-28 14:28:53 UTC

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 2013-12-10 14:25:21 UTC
This is now public via:


Comment 4 Petr Matousek 2013-12-10 14:26:09 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1040024]

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