1. Ubuntu Security Notices
  2. USN-4343-1

USN-4343-1: Linux kernel vulnerability

Publication date

28 April 2020

Overview

Systems running on s390x architecture could be made to crash or run programs as an administrator under certain conditions.

Releases

Packages

Details

Al Viro discovered that the Linux kernel for s390x systems did not properly
perform page table upgrades for kernel sections that use secondary address
mode. A local attacker could use this to cause a denial of service (system
crash) or execute arbitrary code.

Al Viro discovered that the Linux kernel for s390x systems did not properly
perform page table upgrades for kernel sections that use secondary address
mode. A local attacker could use this to cause a denial of service (system
crash) or execute arbitrary code.

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-5.4.0-28-generic –  5.4.0-28.32
linux-image-5.4.0-28-generic-lpae –  5.4.0-28.32
linux-image-5.4.0-28-lowlatency –  5.4.0-28.32
linux-image-generic –  5.4.0.28.33
linux-image-generic-lpae –  5.4.0.28.33
linux-image-lowlatency –  5.4.0.28.33
linux-image-oem –  5.4.0.28.33
linux-image-oem-osp1 –  5.4.0.28.33
linux-image-virtual –  5.4.0.28.33

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 ›