USN-3509-4: Linux kernel (Xenial HWE) regression

Ubuntu Security Notice USN-3509-4

15th December, 2017

linux-lts-xenial, linux-aws regression

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

  • Ubuntu 14.04 LTS


USN-3509-2 introduced a regression in the Linux HWE kernel for Ubuntu 14.04 LTS.

Software description

  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty


USN-3509-2 fixed vulnerabilities in the Linux Hardware Enablement
kernel for Ubuntu 14.04 LTS. Unfortunately, it also introduced a
regression that prevented the Ceph network filesystem from being
used. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

Mohamed Ghannam discovered that a use-after-free vulnerability existed in
the Netlink subsystem (XFRM) in the Linux kernel. A local attacker could
use this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2017-16939)

It was discovered that the Linux kernel did not properly handle copy-on-
write of transparent huge pages. A local attacker could use this to cause a
denial of service (application crashes) or possibly gain administrative
privileges. (CVE-2017-1000405)

Fan Wu, Haoran Qiu, and Shixiong Zhao discovered that the associative array
implementation in the Linux kernel sometimes did not properly handle adding
a new entry. A local attacker could use this to cause a denial of service
(system crash). (CVE-2017-12193)

Andrey Konovalov discovered an out-of-bounds read in the GTCO digitizer USB
driver for the Linux kernel. A physically proximate attacker could use this
to cause a denial of service (system crash) or possibly execute arbitrary
code. (CVE-2017-16643)

Update instructions

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

Ubuntu 14.04 LTS:
linux-image-4.4.0-104-powerpc64-smp 4.4.0-104.127~14.04.1
linux-image-4.4.0-104-lowlatency 4.4.0-104.127~14.04.1
linux-image-4.4.0-104-powerpc64-emb 4.4.0-104.127~14.04.1
linux-image-4.4.0-104-powerpc-smp 4.4.0-104.127~14.04.1
linux-image-4.4.0-104-powerpc-e500mc 4.4.0-104.127~14.04.1
linux-image-4.4.0-1006-aws 4.4.0-1006.6
linux-image-4.4.0-104-generic 4.4.0-104.127~14.04.1
linux-image-4.4.0-104-generic-lpae 4.4.0-104.127~14.04.1

To update your system, please follow these instructions:

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.


LP: 1737033,