A Linux kernel (HWE) security update is available for Ubuntu Linux 18.04 LTS.

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Ubuntu Security Notice USN-4253-2
January 28, 2020

linux-hwe vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS

Summary:

he Linux kernel could be made to expose sensitive information.

Software Description:
- linux-hwe: Linux hardware enablement (HWE) kernel

Details:

USN-4253-1 fixed vulnerabilities in the Linux kernel for Ubuntu 19.10.
This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 19.10 for Ubuntu
18.04 LTS.

It was discovered that the Linux kernel did not properly clear data
structures on context switches for certain Intel graphics processors. A
local attacker could use this to expose sensitive information.

Update instructions:

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

Ubuntu 18.04 LTS:
linux-image-5.3.0-28-generic 5.3.0-28.30~18.04.1
linux-image-5.3.0-28-generic-lpae 5.3.0-28.30~18.04.1
linux-image-5.3.0-28-lowlatency 5.3.0-28.30~18.04.1
linux-image-generic-hwe-18.04 5.3.0.28.96
linux-image-generic-lpae-hwe-18.04 5.3.0.28.96
linux-image-lowlatency-hwe-18.04 5.3.0.28.96
linux-image-snapdragon-hwe-18.04 5.3.0.28.96
linux-image-virtual-hwe-18.04 5.3.0.28.96

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/4253-2
  https://usn.ubuntu.com/4253-1
CVE-2019-14615

Package Information:
  https://launchpad.net/ubuntu/+source/linux-hwe/5.3.0-28.30~18.04.1