A Linux kernel security update has been released for Ubuntu Linux 16.04 ESM and 18.04 LTS.

USN-5357-2: Linux kernel vulnerability

=========================================================================
Ubuntu Security Notice USN-5357-2
March 31, 2022

linux-aws-hwe, linux-gcp-4.15, linux-oracle vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 ESM

Summary:

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

Software Description:
- linux-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems
- linux-oracle: Linux kernel for Oracle Cloud systems
- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems

Details:

It was discovered that the IPsec implementation in the Linux
kernel did not properly allocate enough memory when performing ESP
transformations, leading to a heap-based buffer overflow. A local
attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code.

Update instructions:

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

Ubuntu 18.04 LTS:
linux-image-4.15.0-1091-oracle 4.15.0-1091.100
linux-image-4.15.0-1120-gcp 4.15.0-1120.134
linux-image-gcp-lts-18.04 4.15.0.1120.139
linux-image-oracle-lts-18.04 4.15.0.1091.101

Ubuntu 16.04 ESM:
linux-image-4.15.0-1091-oracle 4.15.0-1091.100~16.04.1
linux-image-4.15.0-1126-aws-hwe 4.15.0-1126.135~16.04.2
linux-image-aws-hwe 4.15.0.1126.116
linux-image-oracle 4.15.0.1091.79

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-5357-2
  https://ubuntu.com/security/notices/USN-5357-1
CVE-2022-27666

Package Information:
  https://launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1120.134
  https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1091.100