USN-4343-1: Linux kernel vulnerability
linux vulnerability
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 20.04 LTS
Summary
Systems running on s390x architecture could be made to crash or run
programs as an administrator under certain conditions.
Software Description
- linux – Linux kernel
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.
Update instructions
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 20.04 LTS
- 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
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
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.