arch/x86/mm.c in Xen allows local PV guest OS users to gain host OS privileges via vectors related to map_grant_ref.Referenceshttps://support.citrix.com/article/CTX225941http://www.openwall.com/lists/oss-security/2017/08/15/2http://www.securitytracker.com/id/1039174https://bugzilla.redhat.com/show_bug.cgi?id=1477657http://www.debian.org/security/2017/dsa-3969https://security.gentoo.org/glsa/201801-14http://www.securityfocus.com/bid/100342http://xenbits.xen.org/xsa/advisory-227.html
