Ubuntu 14.04 LTS USN-6645-1: Critical Kernel Denial of Service

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 14.04 LTS (Available with Ubuntu Pro):
   linux-image-3.13.0-196-generic  3.13.0-196.247
   linux-image-3.13.0-196-lowlatency  3.13.0-196.247
   linux-image-generic             3.13.0.196.206
   linux-image-generic-lts-trusty  3.13.0.196.206
   linux-image-lowlatency          3.13.0.196.206
   linux-image-server              3.13.0.196.206
   linux-image-virtual             3.13.0.196.206

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.