The ioapic_read_indirect function in virt/kvm/ioapic.c in the Linux kernel through 3.8.4 does not properly handle a certain combination of invalid IOAPIC_REG_SELECT and IOAPIC_REG_WINDOW operations, which allows guest OS users to obtain sensitive information from host OS memory or cause a denial of service (host OS OOPS) via a crafted application.
https://bugzilla.redhat.com/show_bug.cgi?id=917017
http://www.ubuntu.com/usn/USN-1813-1
http://www.ubuntu.com/usn/USN-1812-1
http://www.ubuntu.com/usn/USN-1809-1
http://www.openwall.com/lists/oss-security/2013/03/20/9
http://www.mandriva.com/security/advisories?name=MDVSA-2013:176
http://rhn.redhat.com/errata/RHSA-2013-1026.html
http://rhn.redhat.com/errata/RHSA-2013-0928.html
http://rhn.redhat.com/errata/RHSA-2013-0746.html
http://rhn.redhat.com/errata/RHSA-2013-0744.html
http://rhn.redhat.com/errata/RHSA-2013-0727.html
http://packetstormsecurity.com/files/157233/Kernel-Live-Patch-Security-Notice-LSN-0065-1.html
http://lists.opensuse.org/opensuse-security-announce/2013-07/msg00018.html
http://lists.opensuse.org/opensuse-security-announce/2013-06/msg00005.html
http://lists.opensuse.org/opensuse-security-announce/2013-05/msg00018.html