Canonical has released a new update for Ubuntu 16.04 LTS (Xenial Xerus) that emerged as its first live kernel patch. This new package has been released for the 64-bit version of the latest Ubuntu and fixes all the security vulnerabilities described in a recent security notice.
Based on the recently released Livepatch Service, the latest Ubuntu 16.04 build enables users to patch kernel vulnerabilities instantly. This omits the need for a reboot after installing the update.
The live kernel patch fixes an important race condition called Dirty Cow, which was reported a few days back. Dirty Cow (CVE-2016-5195) gives the administrator access to the attacker. Further, the race condition existed in memory manager of Linux kernel while handling read-only memory mappings. Linus Torvalds made an unsuccessful attempt at fixing the vulnerability 11 years ago.
Additionally, the update patches a couple of vital vulnerabilities (CVE-2016-7039 and CVE-2016-8666) that could allow a remote attacker to leverage denial of service to cause a stack corruption. These are unbounded recursion in VLAN and TED Generic Receive Offload (GRO) processing implementation.
All Ubuntu 16.04 LTS (Xenial Xerus) users are recommended to update the kernel with latest live patch version 13.3. You can manually install an updated kernel with mentioned fixes. However, Canonical advises a reboot after installing the newest package.