The get_rx_bufs function in drivers/vhost/net.c in the vhost-net subsystem in the Linux kernel package before 2.6.32-431.11.2 on Red Hat Enterprise Linux (RHEL) 6 does not properly handle vhost_get_vq_desc errors, which allows guest OS users to cause a denial of service (host OS crash) via unspecified vectors.
http://rhn.redhat.com/errata/RHSA-2014-0328.html
http://rhn.redhat.com/errata/RHSA-2014-0339.html