Mandriva Linux Security Advisory 2014-249 – During migration, the values read from migration stream during ram load are not validated. Especially offset in host_from_stream_offset() and also the length of the writes in the callers of the said function. A user able to alter the savevm data (either on the disk or over the wire during migration) could use either of these flaws to corrupt QEMU process memory on the host, which could potentially result in arbitrary code execution on the host with the privileges of the QEMU process. Paolo Bonzini of Red Hat discovered that the blit region checks were insufficient in the Cirrus VGA emulator in qemu. A privileged guest user could use this flaw to write into qemu address space on the host, potentially escalating their privileges to those of the qemu host process.