Few days back, Canonical, the company behind Ubuntu, posted two new security notices on multiple Linux kernel vulnerabilities patched for Ubuntu 12.04 LTS (Precise Pangolin) and Ubuntu 15.10 (Wily Werewolf) operating systems.
Upgrading the kernel packages of your Ubuntu 14.04 LTS (Trusty Tahr) operating system to linux-image-3.13.0-83 (3.13.0-83.127), linux-image-3.16.0-67 (3.16.0-67.87~14.04.1), linux-image-3.19.0-56 (3.19.0-56.62~14.04.1), or linux-image-4.2.0-34 (4.2.0-34.39~14.04.1) will ensure that all the security issues mentioned in there are fixed.
Users on Ubuntu 14.04 LTS should update immediately
Canonical has urged users running Ubuntu 14.04 long-term release with Linux kernel 3.13 to update their system immediately. For updating, simply open the Unity Dash, search for Software Updater and run the application.
Once the software tool refreshes main repositories and discovers new updates, click on the “Install All” button to update your system. Later, when the kernel update completes, you will be asked to reboot the system. Don’t avoid this.
In case you have third-party kernel modules installed on your system, you might need to rebuilt them after the kernel update. More information can be found here: https://wiki.ubuntu.com/Security/Upgrades.