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.
http://lists.opensuse.org/opensuse-security-announce/2015-03/msg00010.html
http://lists.opensuse.org/opensuse-security-announce/2015-03/msg00025.html
http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00015.html
http://rhn.redhat.com/errata/RHSA-2015-0674.html
https://bugzilla.redhat.com/show_bug.cgi?id=1156518
https://github.com/torvalds/linux/commit/3d32e4dbe71374a6780eaf51d719d76f9a9bf22f