==========================================================================
Ubuntu Security Notice USN-3169-1
January 11, 2017

linux vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in the kernel.

Software Description:
- linux: Linux kernel

Details:

Dmitry Vyukov discovered that the KVM implementation in the Linux kernel
did not properly initialize the Code Segment (CS) in certain error cases. A
local attacker could use this to expose sensitive information (kernel
memory). (CVE-2016-9756)

Andrey Konovalov discovered that signed integer overflows existed in the
setsockopt() system call when handling the SO_SNDBUFFORCE and
SO_RCVBUFFORCE options. A local attacker with the CAP_NET_ADMIN capability
could use this to cause a denial of service (system crash or memory
corruption). (CVE-2016-9793)

Baozeng Ding discovered a race condition that could lead to a use-after-
free in the Advanced Linux Sound Architecture (ALSA) subsystem of the Linux
kernel. A local attacker could use this to cause a denial of service
(system crash). (CVE-2016-9794)

Update instructions:

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-59-generic    4.4.0-59.80
  linux-image-4.4.0-59-generic-lpae  4.4.0-59.80
  linux-image-4.4.0-59-lowlatency  4.4.0-59.80
  linux-image-4.4.0-59-powerpc-e500mc  4.4.0-59.80
  linux-image-4.4.0-59-powerpc-smp  4.4.0-59.80
  linux-image-4.4.0-59-powerpc64-emb  4.4.0-59.80
  linux-image-4.4.0-59-powerpc64-smp  4.4.0-59.80
  linux-image-generic             4.4.0.59.62
  linux-image-generic-lpae        4.4.0.59.62
  linux-image-lowlatency          4.4.0.59.62
  linux-image-powerpc-e500mc      4.4.0.59.62
  linux-image-powerpc-smp         4.4.0.59.62
  linux-image-powerpc64-emb       4.4.0.59.62
  linux-image-powerpc64-smp       4.4.0.59.62

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:
  http://www.ubuntu.com/usn/usn-3169-1
  CVE-2016-9756, CVE-2016-9793, CVE-2016-9794

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.4.0-59.80