KVM (Kernel-based Virtual Machine) is a full virtualization solution forLinux on AMD64 and Intel 64 systems. qemu-kvm is the user-space componentfor running virtual machines using KVM.It was found that the virtio-blk driver in qemu-kvm did not properlyvalidate read and write requests from guests. A privileged guest user coulduse this flaw to crash the guest or, possibly, execute arbitrary code onthe host. (CVE-2011-1750)It was found that the PIIX4 Power Management emulation layer in qemu-kvmdid not properly check for hot plug eligibility during device removals. Aprivileged guest user could use this flaw to crash the guest or, possibly,execute arbitrary code on the host. (CVE-2011-1751)Red Hat would like to thank Nelson Elhage for reporting CVE-2011-1751.This update also fixes several bugs and adds various enhancements.Documentation for these bug fixes and enhancements will be availableshortly from the Technical Notes document, linked to in the Referencessection.All users of qemu-kvm should upgrade to these updated packages, whichcontain backported patches to resolve these issues, and fix the bugs andadd the enhancements noted in the Technical Notes. After installing thisupdate, shut down all running virtual machines. Once all virtual machineshave shut down, start them again for this update to take effect.