USN-2647-1: Linux kernel vulnerability

Description

Philip Pettersson discovered a privilege escalation when using overlayfsmounts inside of user namespaces. A local user could exploit this flaw togain administrative privileges on the system. The problem can be corrected by updating your system to the following package version: 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 makeall the necessary changes. ATTENTION: Due to an unavoidable ABI change the kernel updates havebeen given a new version number, which requires you to recompile andreinstall all third party kernel modules you might have installed. Ifyou use linux-restricted-modules, you have to update that package aswell to get modules which work with the new kernel version. Unless youmanually uninstalled the standard kernel metapackages (e.g. linux-generic,linux-server, linux-powerpc), a standard system upgrade will automaticallyperform this as well. CVE-2015-1328