USN-2978-1: Linux kernel vulnerabilities

16 May 2016

linux vulnerabilities

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

  • Ubuntu 15.10

Summary

Several security issues were fixed in the kernel.

Software Description

  • linux - Linux kernel

Details

David Matlack discovered that the Kernel-based Virtual Machine (KVM) implementation in the Linux kernel did not properly restrict variable Memory Type Range Registers (MTRR) in KVM guests. A privileged user in a guest VM could use this to cause a denial of service (system crash) in the host, expose sensitive information from the host, or possibly gain administrative privileges in the host. (CVE-2016-3713)

Philip Pettersson discovered that the Linux kernel’s ASN.1 DER decoder did not properly process certificate files with tags of indefinite length. A local unprivileged attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges. (CVE-2016-0758)

Update instructions

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

Ubuntu 15.10
linux-image-4.2.0-36-generic - 4.2.0-36.42
linux-image-4.2.0-36-generic-lpae - 4.2.0-36.42
linux-image-4.2.0-36-lowlatency - 4.2.0-36.42
linux-image-4.2.0-36-powerpc-e500mc - 4.2.0-36.42
linux-image-4.2.0-36-powerpc-smp - 4.2.0-36.42
linux-image-4.2.0-36-powerpc64-emb - 4.2.0-36.42
linux-image-4.2.0-36-powerpc64-smp - 4.2.0-36.42

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