The libvirt library is a C API for managing and interacting with the virtualization capabilities of Linux and other operating systems. In addition, libvirt provides tools for remote management of virtualized systems. A flaw was found in libvirtd"s RPC call handling. An attacker able to establish a read-only connection to libvirtd could use this flaw to crash libvirtd by sending an RPC message that has an event as the RPC number, or an RPC number that falls into a gap in the RPC dispatch table. This issue was discovered by Wenlong Huang of the Red Hat Virtualization QE Team. This update also fixes the following bugs: * When the host_uuid option was present in the libvirtd.conf file, the augeas libvirt lens was unable to parse the file. This bug has been fixed and the augeas libvirt lens now parses libvirtd.conf as expected in the described scenario. * Disk hot plug is a two-part action: the qemuMonitorAddDrive call is followed by the qemuMonitorAddDevice call. When the first part succeeded but the second one failed, libvirt failed to roll back the first part and the device remained in use even though the disk hot plug failed. With this update, the rollback for the drive addition is properly performed in the described scenario and disk hot plug now works as expected. * When a virtual machine was started with an image chain using block devices and a block rebase operation was issued, the operation failed on completion in the blockJobAbort function. This update relabels and configures cgroups for the backing files and the rebase operation now succeeds. All users of libvirt are advised to upgrade to these updated packages, which contain backported patches to correct these issues. After installing the updated packages, libvirtd will be restarted automatically.