The Xen netback functionality in the Linux kernel before 3.7.8 allows guest OS users to cause a denial of service (loop) by triggering ring pointer corruption.
https://bugzilla.redhat.com/show_bug.cgi?id=910883
http://www.openwall.com/lists/oss-security/2013/02/05/12
http://www.mandriva.com/security/advisories?name=MDVSA-2013:176
http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.7.8
http://lists.opensuse.org/opensuse-security-announce/2013-06/msg00005.html
http://lists.opensuse.org/opensuse-security-announce/2013-04/msg00018.html
http://lists.opensuse.org/opensuse-security-announce/2013-03/msg00004.html