USN-3207-2: Linux kernel (Trusty HWE) vulnerabilities

Ubuntu Security Notice USN-3207-2

21st February, 2017

linux-lts-trusty vulnerabilities

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

  • Ubuntu 12.04 LTS

Summary

Several security issues were fixed in the kernel.

Software description

  • linux-lts-trusty - Linux hardware enablement kernel from Trusty for Precise

Details

USN-3207-1 fixed vulnerabilities in the Linux kernel for Ubuntu 14.04
LTS. This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 14.04 LTS for Ubuntu
12.04 LTS.

It was discovered that a use-after-free vulnerability existed in the block
device layer of the Linux kernel. A local attacker could use this to cause
a denial of service (system crash) or possibly gain administrative
privileges. (CVE-2016-7910)

Dmitry Vyukov discovered a use-after-free vulnerability in the
sys_ioprio_get() function in the Linux kernel. A local attacker could use
this to cause a denial of service (system crash) or possibly gain
administrative privileges. (CVE-2016-7911)

Andrey Konovalov discovered a use-after-free vulnerability in the DCCP
implementation in the Linux kernel. A local attacker could use this to
cause a denial of service (system crash) or possibly gain administrative
privileges. (CVE-2017-6074)

Update instructions

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

Ubuntu 12.04 LTS:
linux-image-generic-lpae-lts-trusty 3.13.0.110.101
linux-image-3.13.0-110-generic 3.13.0-110.157~precise1
linux-image-generic-lts-trusty 3.13.0.110.101
linux-image-3.13.0-110-generic-lpae 3.13.0-110.157~precise1

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

CVE-2016-7910, CVE-2016-7911, CVE-2017-6074