==========================================================================
Ubuntu Security Notice USN-3443-1
October 10, 2017

linux, linux-raspi2 vulnerabilities
==========================================================================

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

- Ubuntu 17.04

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux: Linux kernel
- linux-raspi2: Linux kernel for Raspberry Pi 2

Details:

It was discovered that on the PowerPC architecture, the kernel did not
properly sanitize the signal stack when handling sigreturn(). A local
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2017-1000255)

Andrey Konovalov discovered that a divide-by-zero error existed in the TCP
stack implementation in the Linux kernel. A local attacker could use this
to cause a denial of service (system crash). (CVE-2017-14106)

Update instructions:

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

Ubuntu 17.04:
  linux-image-4.10.0-1019-raspi2  4.10.0-1019.22
  linux-image-4.10.0-37-generic   4.10.0-37.41
  linux-image-4.10.0-37-generic-lpae  4.10.0-37.41
  linux-image-4.10.0-37-lowlatency  4.10.0-37.41
  linux-image-generic             4.10.0.37.37
  linux-image-generic-lpae        4.10.0.37.37
  linux-image-lowlatency          4.10.0.37.37
  linux-image-powerpc-e500mc      4.10.0.37.37
  linux-image-powerpc-smp         4.10.0.37.37
  linux-image-powerpc64-emb       4.10.0.37.37
  linux-image-powerpc64-smp       4.10.0.37.37
  linux-image-raspi2              4.10.0.1019.20
  linux-image-virtual             4.10.0.37.37

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://www.ubuntu.com/usn/usn-3443-1
  CVE-2017-1000255, CVE-2017-14106

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.10.0-37.41
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.10.0-1019.22