The HVMOP_inject_msi function in Xen 4.2.x, 4.3.x, and 4.4.x does not properly check the return value from the IRQ setup check, which allows local HVM guest administrators to cause a denial of service (NULL pointer dereference and crash) via unspecified vectors.
lists.fedoraproject.org/pipermail/package-announce/2014-June/134710.html
lists.fedoraproject.org/pipermail/package-announce/2014-June/134739.html
lists.opensuse.org/opensuse-security-announce/2014-10/msg00002.html
lists.opensuse.org/opensuse-security-announce/2014-10/msg00003.html
www.openwall.com/lists/oss-security/2014/06/04/13
www.securityfocus.com/bid/67794
www.securitytracker.com/id/1030322
xenbits.xen.org/xsa/advisory-96.html
security.gentoo.org/glsa/201504-04