Ubuntu 20.10 Security Advisory USN-4626-1: Critical Kernel Flaws

ubuntu

November 10, 2020

Several security issues were fixed in the Linux kernel.

Summary

Several security issues were fixed in the Linux kernel.

Software Description:

- linux: Linux kernel

- linux-aws: Linux kernel for Amazon Web Services (AWS) systems

- linux-azure: Linux kernel for Microsoft Azure Cloud systems

- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems

- linux-kvm: Linux kernel for cloud environments

- linux-oracle: Linux kernel for Oracle Cloud systems

- linux-raspi: Linux kernel for Raspberry Pi (V8) systems

Details:

Simon Scannell discovered that the bpf verifier in the Linux kernel did not

properly calculate register bounds for certain operations. A local attacker

could use this to expose sensitive information (kernel memory) or gain

administrative privileges. (CVE-2020-27194)

Moritz Lipp, Michael Schwarz, Andreas Kogler, David Oswald, Catherine

Easdon, Claudio Canella, and Daniel Gruss discovered that the Intel Running

Average Power Limit (RAPL) driver in the Linux kernel did not properly

restrict access to power data. A local attacke...

Read the Full Advisory

Topics Covered

security advisory buffer overflow ubuntu sensitive information linux kernel

Update Instructions

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

Ubuntu 20.10:
  linux-image-5.8.0-1007-raspi    5.8.0-1007.10
  linux-image-5.8.0-1007-raspi-nolpae  5.8.0-1007.10
  linux-image-5.8.0-1009-kvm      5.8.0-1009.10
  linux-image-5.8.0-1010-oracle   5.8.0-1010.10
  linux-image-5.8.0-1011-gcp      5.8.0-1011.11
  linux-image-5.8.0-1012-azure    5.8.0-1012.13
  linux-image-5.8.0-1013-aws      5.8.0-1013.14
  linux-image-5.8.0-28-generic    5.8.0-28.30
  linux-image-5.8.0-28-generic-64k  5.8.0-28.30
  linux-image-5.8.0-28-generic-lpae  5.8.0-28.30
  linux-image-5.8.0-28-lowlatency  5.8.0-28.30
  linux-image-aws                 5.8.0.1013.15
  linux-image-azure               5.8.0.1012.12
  linux-image-gcp                 5.8.0.1011.11
  linux-image-generic             5.8.0.28.33
  linux-image-generic-64k         5.8.0.28.33
  linux-image-generic-lpae        5.8.0.28.33
  linux-image-gke                 5.8.0.1011.11
  linux-image-kvm                 5.8.0.1009.10
  linux-image-lowlatency          5.8.0.28.33
  linux-image-oem-20.04           5.8.0.28.33
  linux-image-oracle              5.8.0.1010.10
  linux-image-raspi               5.8.0.1007.10
  linux-image-raspi-nolpae        5.8.0.1007.10
  linux-image-virtual             5.8.0.28.33

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.