USN-4303-2: Linux kernel (HWE) vulnerability

17 March 2020

linux-lts-xenial, linux-aws vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 14.04 ESM

Summary

The system could be made to expose sensitive information.

Software Description

  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty

Details

USN-4303-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 ESM.

Paulo Bonzini discovered that the KVM hypervisor implementation in the Linux kernel could improperly let a nested (level 2) guest access the resources of a parent (level 1) guest in certain situations. An attacker could use this to expose sensitive information.

Update instructions

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

Ubuntu 14.04 ESM
linux-image-4.4.0-1064-aws - 4.4.0-1064.68
linux-image-4.4.0-176-generic - 4.4.0-176.206~14.04.1
linux-image-4.4.0-176-generic-lpae - 4.4.0-176.206~14.04.1
linux-image-4.4.0-176-lowlatency - 4.4.0-176.206~14.04.1
linux-image-4.4.0-176-powerpc-e500mc - 4.4.0-176.206~14.04.1
linux-image-4.4.0-176-powerpc-smp - 4.4.0-176.206~14.04.1
linux-image-4.4.0-176-powerpc64-emb - 4.4.0-176.206~14.04.1
linux-image-4.4.0-176-powerpc64-smp - 4.4.0-176.206~14.04.1
linux-image-aws - 4.4.0.1064.65
linux-image-generic-lpae-lts-xenial - 4.4.0.176.155
linux-image-generic-lts-xenial - 4.4.0.176.155
linux-image-lowlatency-lts-xenial - 4.4.0.176.155
linux-image-powerpc-e500mc-lts-xenial - 4.4.0.176.155
linux-image-powerpc-smp-lts-xenial - 4.4.0.176.155
linux-image-powerpc64-emb-lts-xenial - 4.4.0.176.155
linux-image-powerpc64-smp-lts-xenial - 4.4.0.176.155
linux-image-virtual-lts-xenial - 4.4.0.176.155

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.

References