1. Ubuntu Security Notices
  2. USN-5217-1

USN-5217-1: Linux kernel (OEM) vulnerabilities

Publication date

11 January 2022

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

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. (CVE-2021-4204)

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. (CVE-2021-4204)

Update instructions

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
20.04 focal linux-image-5.14.0-1018-oem –  5.14.0-1018.19
linux-image-oem-20.04d –  5.14.0.1018.16

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Get Ubuntu Pro

References

Have additional questions?

Talk to a member of the team ›