A Linux kernel security update has been released for Ubuntu Linux 16.04 LTS and 14.04 ESM.

USN-4486-1: Linux kernel vulnerability

=========================================================================
Ubuntu Security Notice USN-4486-1
September 02, 2020

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

- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM

Summary:

The Linux kernel could be made to crash if it mounted a malicious XFS
file system.

Software Description:
- linux: Linux kernel
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-kvm: Linux kernel for cloud environments
- linux-raspi2: Linux kernel for Raspberry Pi (V8) systems
- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors
- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty

Details:

Wen Xu discovered that the XFS filesystem implementation in the Linux
kernel did not properly validate meta-data information. An attacker could
use this to construct a malicious xfs image that, when mounted, could cause
a denial of service (system crash).

Update instructions:

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

Ubuntu 16.04 LTS:
linux-image-4.4.0-1079-kvm 4.4.0-1079.86
linux-image-4.4.0-1113-aws 4.4.0-1113.126
linux-image-4.4.0-1138-raspi2 4.4.0-1138.147
linux-image-4.4.0-1142-snapdragon 4.4.0-1142.151
linux-image-4.4.0-189-generic 4.4.0-189.219
linux-image-4.4.0-189-generic-lpae 4.4.0-189.219
linux-image-4.4.0-189-lowlatency 4.4.0-189.219
linux-image-4.4.0-189-powerpc-e500mc 4.4.0-189.219
linux-image-4.4.0-189-powerpc-smp 4.4.0-189.219
linux-image-4.4.0-189-powerpc64-emb 4.4.0-189.219
linux-image-4.4.0-189-powerpc64-smp 4.4.0-189.219
linux-image-aws 4.4.0.1113.118
linux-image-generic 4.4.0.189.195
linux-image-generic-lpae 4.4.0.189.195
linux-image-kvm 4.4.0.1079.77
linux-image-lowlatency 4.4.0.189.195
linux-image-powerpc-e500mc 4.4.0.189.195
linux-image-powerpc-smp 4.4.0.189.195
linux-image-powerpc64-emb 4.4.0.189.195
linux-image-powerpc64-smp 4.4.0.189.195
linux-image-raspi2 4.4.0.1138.138
linux-image-snapdragon 4.4.0.1142.134
linux-image-virtual 4.4.0.189.195

Ubuntu 14.04 ESM:
linux-image-4.4.0-1077-aws 4.4.0-1077.81
linux-image-4.4.0-189-generic 4.4.0-189.219~14.04.1
linux-image-4.4.0-189-generic-lpae 4.4.0-189.219~14.04.1
linux-image-4.4.0-189-lowlatency 4.4.0-189.219~14.04.1
linux-image-4.4.0-189-powerpc-e500mc 4.4.0-189.219~14.04.1
linux-image-4.4.0-189-powerpc-smp 4.4.0-189.219~14.04.1
linux-image-4.4.0-189-powerpc64-emb 4.4.0-189.219~14.04.1
linux-image-4.4.0-189-powerpc64-smp 4.4.0-189.219~14.04.1
linux-image-aws 4.4.0.1077.74
linux-image-generic-lpae-lts-xenial 4.4.0.189.165
linux-image-generic-lts-xenial 4.4.0.189.165
linux-image-lowlatency-lts-xenial 4.4.0.189.165
linux-image-powerpc-e500mc-lts-xenial 4.4.0.189.165
linux-image-powerpc-smp-lts-xenial 4.4.0.189.165
linux-image-powerpc64-emb-lts-xenial 4.4.0.189.165
linux-image-powerpc64-smp-lts-xenial 4.4.0.189.165
linux-image-virtual-lts-xenial 4.4.0.189.165

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/4486-1
CVE-2018-10323

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.4.0-189.219
  https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1113.126
  https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1079.86
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.4.0-1138.147
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1142.151