A Linux kernel (Raspberry Pi) security update has been released for Ubuntu Linux 18.04 LTS and 20.04 LTS.

USN-6069-1: Linux kernel (Raspberry Pi) vulnerability

==========================================================================
Ubuntu Security Notice USN-6069-1
May 10, 2023

linux-raspi, linux-raspi-5.4, linux-raspi2 vulnerability
==========================================================================

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

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

The system could be made to run programs as an administrator.

Software Description:
- linux-raspi: Linux kernel for Raspberry Pi systems
- linux-raspi-5.4: Linux kernel for Raspberry Pi systems
- linux-raspi2: Linux kernel for Raspberry Pi systems

Details:

It was discovered that the Traffic-Control Index (TCINDEX) implementation
in the Linux kernel did not properly perform filter deactivation in some
situations. A local attacker could possibly use this to gain elevated
privileges. Please note that with the fix for this CVE, kernel support for
the TCINDEX classifier has been removed.

Update instructions:

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

Ubuntu 20.04 LTS:
linux-image-5.4.0-1084-raspi 5.4.0-1084.95
linux-image-raspi 5.4.0.1084.114
linux-image-raspi2 5.4.0.1084.114

Ubuntu 18.04 LTS:
linux-image-4.15.0-1131-raspi2 4.15.0-1131.139
linux-image-5.4.0-1084-raspi 5.4.0-1084.95~18.04.1
linux-image-raspi-hwe-18.04 5.4.0.1084.81
linux-image-raspi2 4.15.0.1131.126

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://ubuntu.com/security/notices/USN-6069-1
CVE-2023-1829

Package Information:
https://launchpad.net/ubuntu/+source/linux-raspi/5.4.0-1084.95
https://launchpad.net/ubuntu/+source/linux-raspi-5.4/5.4.0-1084.95~18.04.1
https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1131.139