The mod_l2_entry function in arch/x86/mm.c in Xen 3.4 through 4.6.x does not properly validate level 2 page table entries, which allows local PV guest administrators to gain privileges via a crafted superpage mapping.Referenceshttp://support.citrix.com/article/CTX202404http://www.securityfocus.com/bid/77366http://lists.fedoraproject.org/pipermail/package-announce/2015-November/171249.htmlhttp://lists.fedoraproject.org/pipermail/package-announce/2015-November/171082.htmlhttp://xenbits.xen.org/xsa/advisory-148.htmlhttp://lists.opensuse.org/opensuse-updates/2015-12/msg00053.htmlhttps://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-022-2015.txthttp://www.debian.org/security/2015/dsa-3390http://www.securitytracker.com/id/1034032http://lists.opensuse.org/opensuse-updates/2015-11/msg00063.htmlhttp://lists.fedoraproject.org/pipermail/package-announce/2015-November/171185.htmlhttps://security.gentoo.org/glsa/201604-03
