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Ubuntu Security Notice USN-6152-1
June 08, 2023

linux-gke regression
==========================================================================

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

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

The system could suffer with performance degradation in certain conditions.

Software Description:
- linux-gke: Linux kernel for Google Container Engine (GKE) systems

Details:

It was discovered that NFS client's access cache implementation in the
Linux kernel caused a severe NFS performance degradation in certain
conditions. This updated makes the NFS file-access stale cache behavior
to be optional.

Update instructions:

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

Ubuntu 22.04 LTS:
   linux-image-5.15.0-1035-gke     5.15.0-1035.40
   linux-image-gke                 5.15.0.1035.34
   linux-image-gke-5.15            5.15.0.1035.34

Ubuntu 20.04 LTS:
   linux-image-5.4.0-1101-gke      5.4.0-1101.108
   linux-image-gke                 5.4.0.1101.106
   linux-image-gke-5.4             5.4.0.1101.106

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-6152-1
   https://launchpad.net/bugs/2022098

Package Information:
   https://launchpad.net/ubuntu/+source/linux-gke/5.15.0-1035.40
   https://launchpad.net/ubuntu/+source/linux-gke/5.4.0-1101.108