A Linux kernel security update has been released Ubuntu Linux 18.04 LTS, 20.04 LTS and 20.10.

USN-4713-1: Linux kernel vulnerability

=========================================================================
Ubuntu Security Notice USN-4713-1
January 28, 2021

linux-aws, linux-aws-5.4, linux-azure, linux-gcp, linux-kvm, linux-oracle,
linux-raspi vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

The system could allow unintended access to data in some environments.

Software Description:
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-azure: Linux kernel for Microsoft Azure Cloud systems
- linux-kvm: Linux kernel for cloud environments
- linux-oracle: Linux kernel for Oracle Cloud systems
- linux-raspi: Linux kernel for Raspberry Pi (V8) systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-aws-5.4: Linux kernel for Amazon Web Services (AWS) systems

Details:

It was discovered that the LIO SCSI target implementation in the Linux
kernel performed insufficient identifier checking in certain XCOPY
requests. An attacker with access to at least one LUN in a multiple
backstore environment could use this to expose sensitive information or
modify data.

Update instructions:

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

Ubuntu 20.10:
linux-image-5.8.0-1013-raspi 5.8.0-1013.16
linux-image-5.8.0-1013-raspi-nolpae 5.8.0-1013.16
linux-image-5.8.0-1016-kvm 5.8.0-1016.18
linux-image-5.8.0-1018-oracle 5.8.0-1018.19
linux-image-5.8.0-1020-azure 5.8.0-1020.22
linux-image-5.8.0-1021-aws 5.8.0-1021.23
linux-image-aws 5.8.0.1021.23
linux-image-azure 5.8.0.1020.20
linux-image-kvm 5.8.0.1016.18
linux-image-oracle 5.8.0.1018.18
linux-image-raspi 5.8.0.1013.16
linux-image-raspi-nolpae 5.8.0.1013.16

Ubuntu 20.04 LTS:
linux-image-5.4.0-1032-kvm 5.4.0-1032.33
linux-image-5.4.0-1036-gcp 5.4.0-1036.39
linux-image-5.4.0-1037-aws 5.4.0-1037.39
linux-image-5.4.0-1037-oracle 5.4.0-1037.40
linux-image-5.4.0-1039-azure 5.4.0-1039.41
linux-image-aws 5.4.0.1037.38
linux-image-azure 5.4.0.1039.37
linux-image-gcp 5.4.0.1036.45
linux-image-kvm 5.4.0.1032.30
linux-image-oracle 5.4.0.1037.34

Ubuntu 18.04 LTS:
linux-image-5.4.0-1037-aws 5.4.0-1037.39~18.04.1
linux-image-aws 5.4.0.1037.21

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/4713-1
CVE-2020-28374

Package Information:
  https://launchpad.net/ubuntu/+source/linux-aws/5.8.0-1021.23
  https://launchpad.net/ubuntu/+source/linux-azure/5.8.0-1020.22
  https://launchpad.net/ubuntu/+source/linux-kvm/5.8.0-1016.18
  https://launchpad.net/ubuntu/+source/linux-oracle/5.8.0-1018.19
  https://launchpad.net/ubuntu/+source/linux-raspi/5.8.0-1013.16
  https://launchpad.net/ubuntu/+source/linux-aws/5.4.0-1037.39
  https://launchpad.net/ubuntu/+source/linux-azure/5.4.0-1039.41
  https://launchpad.net/ubuntu/+source/linux-gcp/5.4.0-1036.39
  https://launchpad.net/ubuntu/+source/linux-kvm/5.4.0-1032.33
  https://launchpad.net/ubuntu/+source/linux-oracle/5.4.0-1037.40
  https://launchpad.net/ubuntu/+source/linux-aws-5.4/5.4.0-1037.39~18.04.1