USN-2979-1: Linux kernel vulnerabilities
16 May 2016
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 16.04 LTS
Several security issues were fixed in the kernel.
- linux - Linux kernel
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)
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 16.04 LTS
- linux-image-4.4.0-22-generic - 4.4.0-22.40
- linux-image-4.4.0-22-generic-lpae - 4.4.0-22.40
- linux-image-4.4.0-22-lowlatency - 4.4.0-22.40
- linux-image-4.4.0-22-powerpc-e500mc - 4.4.0-22.40
- linux-image-4.4.0-22-powerpc-smp - 4.4.0-22.40
- linux-image-4.4.0-22-powerpc64-emb - 4.4.0-22.40
- linux-image-4.4.0-22-powerpc64-smp - 4.4.0-22.40
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.