=========================================================================
Ubuntu Security Notice USN-4161-1
October 21, 2019

linux, linux-aws, linux-azure, linux-gcp, linux-kvm, linux-raspi2
vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 19.10

Summary:

The system could be made to crash under certain conditions.

Software Description:
- linux: Linux kernel
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-azure: Linux kernel for Microsoft Azure Cloud 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:

It was discovered that the IPv6 routing implementation in the Linux kernel
contained a reference counting error leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code.

Update instructions:

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

Ubuntu 19.10:
  linux-image-5.3.0-1004-aws      5.3.0-1004.4
  linux-image-5.3.0-1004-azure    5.3.0-1004.4
  linux-image-5.3.0-1004-kvm      5.3.0-1004.4
  linux-image-5.3.0-1005-gcp      5.3.0-1005.5
  linux-image-5.3.0-1008-raspi2   5.3.0-1008.9
  linux-image-5.3.0-19-generic    5.3.0-19.20
  linux-image-5.3.0-19-generic-lpae  5.3.0-19.20
  linux-image-5.3.0-19-lowlatency  5.3.0-19.20
  linux-image-5.3.0-19-snapdragon  5.3.0-19.20
  linux-image-aws                 5.3.0.1004.5
  linux-image-azure               5.3.0.1004.21
  linux-image-gcp                 5.3.0.1005.5
  linux-image-generic             5.3.0.19.22
  linux-image-generic-lpae        5.3.0.19.22
  linux-image-gke                 5.3.0.1005.5
  linux-image-kvm                 5.3.0.1004.4
  linux-image-lowlatency          5.3.0.19.22
  linux-image-raspi2              5.3.0.1008.4
  linux-image-snapdragon          5.3.0.19.22
  linux-image-virtual             5.3.0.19.22

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/4161-1
  CVE-2019-18198

Package Information:
  https://launchpad.net/ubuntu/+source/linux/5.3.0-19.20
  https://launchpad.net/ubuntu/+source/linux-aws/5.3.0-1004.4
  https://launchpad.net/ubuntu/+source/linux-azure/5.3.0-1004.4
  https://launchpad.net/ubuntu/+source/linux-gcp/5.3.0-1005.5
  https://launchpad.net/ubuntu/+source/linux-kvm/5.3.0-1004.4
  https://launchpad.net/ubuntu/+source/linux-raspi2/5.3.0-1008.9