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Ubuntu Security Notice USN-5217-1
January 11, 2022

linux-oem-5.14 vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-oem-5.14: Linux kernel for OEM systems

Details:

It was discovered that the NFS server implementation in the Linux kernel
contained an out-of-bounds write vulnerability. A local attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2021-4090)

It was discovered that the eBPF implementation in the Linux kernel did
not properly validate the memory size of certain ring buffer operation
arguments. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (LP: #1956585)

Update instructions:

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

Ubuntu 20.04 LTS:
  linux-image-5.14.0-1018-oem     5.14.0-1018.19
  linux-image-oem-20.04d          5.14.0.1018.16

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-5217-1
  CVE-2021-4090, https://launchpad.net/bugs/1956585

Package Information:
  https://launchpad.net/ubuntu/+source/linux-oem-5.14/5.14.0-1018.19