==========================================================================
Ubuntu Security Notice USN-4006-1
June 04, 2019

linux, linux-aws, linux-gcp, linux-kvm, linux-raspi2 vulnerability
==========================================================================

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

- Ubuntu 18.10

Summary:

A system hardening measure could be bypassed.

Software Description:
- linux: Linux kernel
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-kvm: Linux kernel for cloud environments
- linux-raspi2: Linux kernel for Raspberry Pi 2

Details:

Federico Manuel Bento discovered that the Linux kernel did not properly
apply Address Space Layout Randomization (ASLR) in some situations for
setuid a.out binaries. A local attacker could use this to improve the
chances of exploiting an existing vulnerability in a setuid a.out binary.

As a hardening measure, this update disables a.out support.

Update instructions:

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

Ubuntu 18.10:
  linux-image-4.18.0-1012-gcp     4.18.0-1012.13
  linux-image-4.18.0-1013-kvm     4.18.0-1013.13
  linux-image-4.18.0-1015-raspi2  4.18.0-1015.17
  linux-image-4.18.0-1017-aws     4.18.0-1017.19
  linux-image-4.18.0-21-generic   4.18.0-21.22
  linux-image-4.18.0-21-generic-lpae  4.18.0-21.22
  linux-image-4.18.0-21-lowlatency  4.18.0-21.22
  linux-image-4.18.0-21-snapdragon  4.18.0-21.22
  linux-image-aws                 4.18.0.1017.17
  linux-image-gcp                 4.18.0.1012.12
  linux-image-generic             4.18.0.21.22
  linux-image-generic-lpae        4.18.0.21.22
  linux-image-gke                 4.18.0.1012.12
  linux-image-kvm                 4.18.0.1013.13
  linux-image-lowlatency          4.18.0.21.22
  linux-image-raspi2              4.18.0.1015.12
  linux-image-snapdragon          4.18.0.21.22

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://usn.ubuntu.com/4006-1
  CVE-2019-11191

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.18.0-21.22
  https://launchpad.net/ubuntu/+source/linux-aws/4.18.0-1017.19
  https://launchpad.net/ubuntu/+source/linux-gcp/4.18.0-1012.13
  https://launchpad.net/ubuntu/+source/linux-kvm/4.18.0-1013.13
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.18.0-1015.17