1. Ubuntu Security Notices
  2. USN-4484-1

USN-4484-1: Linux kernel vulnerability

Publication date

2 September 2020

Overview

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

Releases

Packages

Details

It was discovered that the cgroup v2 subsystem in the Linux kernel did not
properly perform reference counting in some situations, leading to a NULL
pointer dereference. A local attacker could use this to cause a denial of
service or possibly gain administrative privileges.

It was discovered that the cgroup v2 subsystem in the Linux kernel did not
properly perform reference counting in some situations, leading to a NULL
pointer dereference. A local attacker could use this to cause a denial of
service or possibly gain administrative privileges.

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
18.04 bionic linux-image-5.3.0-1032-raspi2 –  5.3.0-1032.34
linux-image-5.3.0-1034-aws –  5.3.0-1034.36
linux-image-5.3.0-1034-gke –  5.3.0-1034.36
linux-image-5.3.0-66-generic –  5.3.0-66.60
linux-image-5.3.0-66-lowlatency –  5.3.0-66.60
linux-image-aws –  5.3.0.1034.33
linux-image-gke-5.3 –  5.3.0.1034.19
linux-image-gkeop-5.3 –  5.3.0.66.123
linux-image-raspi2-hwe-18.04 –  5.3.0.1032.22

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References

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