Re: [Xen-users] [oss-security] Xen Security Advisory 78 - Insufficient TLB flushing in VT-d (iommu) code

[Kurt Seifried <kseifried@xxxxxxxxxx>]

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On 11/20/2013 10:08 AM, Xen.org security team wrote:
> Xen Security Advisory XSA-78
> 
> Insufficient TLB flushing in VT-d (iommu) code
> 
> ISSUE DESCRIPTION =================
> 
> An inverted boolean parameter resulted in TLB flushes not
> happening upon clearing of a present translation table entry.
> Retaining stale TLB entries could allow guests access to memory
> that ought to have been revoked, or grant greater access than
> intended.
> 
> IMPACT ======
> 
> Malicious guest administrators might be able to cause host-wide
> denial of service, or escalate their privilege to that of the
> host.
> 
> VULNERABLE SYSTEMS ==================
> 
> Xen 4.2.x and later are vulnerable. Xen 4.1.x and earlier are not
> vulnerable.
> 
> Only systems using Intel VT-d for PCI passthrough are vulnerable.
> 
> MITIGATION ==========
> 
> This issue can be avoided by not assigning PCI devices to untrusted
> guests on systems supporting Intel VT-d.
> 
> NOTE REGARDING LACK OF EMBARGO ==============================
> 
> This issue was disclosed publicly on the xen-devel mailing list.
> 
> RESOLUTION ==========
> 
> Applying the attached patch resolves this issue.
> 
> xsa78.patch        Xen 4.2.x, Xen 4.3.x, xen-unstable
> 
> $ sha256sum xsa78*.patch 
> 2b858188495542b393532dfeb108ae95cbb507a008b5ebf430b96c95272f9e0e
> xsa78.patch $

Please use CVE-2013-6375 for this issue.


- -- 
Kurt Seifried Red Hat Security Response Team (SRT)
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