USN-2978-2: Linux kernel (Wily HWE) vulnerabilities

Ubuntu Security Notice USN-2978-2

16th May, 2016

linux-lts-wily vulnerabilities

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

• Ubuntu 14.04 LTS

Summary

Several security issues were fixed in the kernel.

Software description

• linux-lts-wily - Linux hardware enablement kernel from Wily for Trusty

Details

USN-2978-1 fixed vulnerabilities in the Linux kernel for Ubuntu 15.10.
This update provides the corresponding updates for the Linux Hardware
Enablement (HWE) kernel from Ubuntu 15.10 for Ubuntu 14.04 LTS.

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 version:

Ubuntu 14.04 LTS:

linux-image-4.2.0-36-generic 4.2.0-36.42~14.04.1

linux-image-4.2.0-36-powerpc64-smp 4.2.0-36.42~14.04.1

linux-image-4.2.0-36-powerpc64-emb 4.2.0-36.42~14.04.1

linux-image-4.2.0-36-powerpc-smp 4.2.0-36.42~14.04.1

linux-image-4.2.0-36-powerpc-e500mc 4.2.0-36.42~14.04.1

linux-image-4.2.0-36-lowlatency 4.2.0-36.42~14.04.1

linux-image-4.2.0-36-generic-lpae 4.2.0-36.42~14.04.1

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-wily, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.

References

CVE-2016-0758, CVE-2016-3713