Several security issues were fixed in the kernel.
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.
22 February 2017
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the kernel.
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)
The problem can be corrected by updating your system to the following package versions:
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.