1. Ubuntu Security Notices
  2. USN-2978-1

USN-2978-1: Linux kernel vulnerabilities

Publication date

16 May 2016

Overview

Several security issues were fixed in the kernel.

Releases

Packages

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)

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

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
15.10 wily linux-image-4.2.0-36-generic-lpae –  4.2.0-36.42
linux-image-4.2.0-36-powerpc64-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-powerpc-smp –  4.2.0-36.42
linux-image-4.2.0-36-powerpc-e500mc –  4.2.0-36.42
linux-image-4.2.0-36-lowlatency –  4.2.0-36.42
linux-image-4.2.0-36-generic –  4.2.0-36.42

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References

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