CVE-2015-2756 Information

Description

QEMU as used in Xen 3.3.x through 4.5.x does not properly restrict access to PCI command registers which might allow local HVM guest users to cause a denial of service (non-maskable interrupt and host crash) by disabling the (1) memory or (2) I/O decoding for a PCI Express device and then accessing the device which triggers an Unsupported Request (UR) response.

Reference

http://lists.fedoraproject.org/pipermail/package-announce/2015-April/154574.html http://lists.fedoraproject.org/pipermail/package-announce/2015-April/154579.html http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155198.html http://lists.nongnu.org/archive/html/qemu-devel/2015-03/msg06179.html http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00014.html http://support.citrix.com/article/CTX201145 http://www.debian.org/security/2015/dsa-3259 http://www.securityfocus.com/bid/72577 http://www.securitytracker.com/id/1031998 http://www.ubuntu.com/usn/USN-2608-1 http://xenbits.xen.org/xsa/advisory-126.html https://security.gentoo.org/glsa/201504-04 https://support.citrix.com/article/CTX206006