USN-4343-1: Linux kernel vulnerability

Releases

• Ubuntu 20.04 LTS

Packages

• 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

• 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

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

• CVE-2020-11884

Related notices

• USN-4345-1
• USN-4342-1