The KVM implementation in the Linux kernel before 3.3.4 does not properly manage the relationships between memory slots and the iommu, which allows guest OS users to cause a denial of service (memory leak and host OS crash) by leveraging administrative access to the guest OS to conduct hotunplug and hotplug operations on devices.
rhn.redhat.com/errata/RHSA-2012-0676.html
rhn.redhat.com/errata/RHSA-2012-0743.html
secunia.com/advisories/50732
www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.3.4
www.openwall.com/lists/oss-security/2012/04/19/16
www.securitytracker.com/id?1027083
www.ubuntu.com/usn/USN-1577-1
www.ubuntu.com/usn/USN-2036-1
www.ubuntu.com/usn/USN-2037-1
bugzilla.redhat.com/show_bug.cgi?id=814149
github.com/torvalds/linux/commit/09ca8e1173bcb12e2a449698c9ae3b86a8a10195