=========================================================================Ubuntu Security Notice USN-3128-2
November 11, 2016

linux-lts-xenial vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 14.04 LTS

Summary:

The system could be made to crash under certain conditions.

Software Description:
- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty

Details:

USN-3128-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04
LTS. This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu
14.04 LTS.

Ondrej Kozina discovered that the keyring interface in the Linux kernel
contained a buffer overflow when displaying timeout events via the
/proc/keys interface. A local attacker could use this to cause a denial of
service (system crash).

Update instructions:

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

Ubuntu 14.04 LTS:
  linux-image-4.4.0-47-generic    4.4.0-47.68~14.04.1
  linux-image-4.4.0-47-generic-lpae  4.4.0-47.68~14.04.1
  linux-image-4.4.0-47-lowlatency  4.4.0-47.68~14.04.1
  linux-image-4.4.0-47-powerpc-e500mc  4.4.0-47.68~14.04.1
  linux-image-4.4.0-47-powerpc-smp  4.4.0-47.68~14.04.1
  linux-image-4.4.0-47-powerpc64-emb  4.4.0-47.68~14.04.1
  linux-image-4.4.0-47-powerpc64-smp  4.4.0-47.68~14.04.1
  linux-image-generic-lpae-lts-xenial  4.4.0.47.34
  linux-image-generic-lts-xenial  4.4.0.47.34
  linux-image-lowlatency-lts-xenial  4.4.0.47.34
  linux-image-powerpc-e500mc-lts-xenial  4.4.0.47.34
  linux-image-powerpc-smp-lts-xenial  4.4.0.47.34
  linux-image-powerpc64-emb-lts-xenial  4.4.0.47.34
  linux-image-powerpc64-smp-lts-xenial  4.4.0.47.34

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.

References:
  https://ubuntu.com/security/notices/USN-3128-2
  https://ubuntu.com/security/notices/USN-3128-1
  CVE-2016-7042

Package Information:
  https://launchpad.net/ubuntu/+source/linux-lts-xenial/4.4.0-47.68~14.04.1