USN-4303-1: Linux kernel vulnerability
linux, linux-aws, linux-kvm vulnerability
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 16.04 LTS
Summary
The system could be made to expose sensitive information.
Software Description
- linux – Linux kernel
- linux-aws – Linux kernel for Amazon Web Services (AWS) systems
- linux-kvm – Linux kernel for cloud environments
Details
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 16.04 LTS
- linux-image-4.4.0-1068-kvm – 4.4.0-1068.75
- linux-image-4.4.0-1104-aws – 4.4.0-1104.115
- linux-image-4.4.0-176-generic – 4.4.0-176.206
- linux-image-4.4.0-176-generic-lpae – 4.4.0-176.206
- linux-image-4.4.0-176-lowlatency – 4.4.0-176.206
- linux-image-4.4.0-176-powerpc-e500mc – 4.4.0-176.206
- linux-image-4.4.0-176-powerpc-smp – 4.4.0-176.206
- linux-image-4.4.0-176-powerpc64-emb – 4.4.0-176.206
- linux-image-4.4.0-176-powerpc64-smp – 4.4.0-176.206
- linux-image-aws – 4.4.0.1104.108
- linux-image-generic – 4.4.0.176.184
- linux-image-generic-lpae – 4.4.0.176.184
- linux-image-kvm – 4.4.0.1068.68
- linux-image-lowlatency – 4.4.0.176.184
- linux-image-powerpc-e500mc – 4.4.0.176.184
- linux-image-powerpc-smp – 4.4.0.176.184
- linux-image-powerpc64-emb – 4.4.0.176.184
- linux-image-powerpc64-smp – 4.4.0.176.184
- linux-image-virtual – 4.4.0.176.184
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.