The kvm_iommu_map_pages function in virt/kvm/iommu.c in the Linux kernel through 3.17.2 miscalculates the number of pages during the handling of a mapping failure, which allows guest OS users to cause a denial of service (host OS page unpinning) or possibly have unspecified other impact by leveraging guest OS privileges. NOTE: this vulnerability exists because of an incorrect fix for CVE-2014-3601.
https://bugzilla.redhat.com/show_bug.cgi?id=1156518
http://www.securityfocus.com/bid/70749
http://www.securityfocus.com/bid/70747
http://www.openwall.com/lists/oss-security/2014/10/24/7
http://www.debian.org/security/2014/dsa-3093
http://rhn.redhat.com/errata/RHSA-2015-0674.html
http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00015.html
http://lists.opensuse.org/opensuse-security-announce/2015-03/msg00025.html
http://lists.opensuse.org/opensuse-security-announce/2015-03/msg00010.html