Last week, Canonical released a kernel update for the Ubuntu 16.04 LTS (Xenial Xerus) operating system patching a total of four security issues, including a use-after-free vulnerability in the Netlink subsystem (XFRM), an out-of-bounds read in the GTCO digitizer USB driver, a bug in the associative array implementation, and improper copy-on-write (COW) handling of transparent huge pages. However, it would appear that the respective kernel update also introduced a regression, which apparently prevented the use of the Ceph network file system on machines that upgraded to the new kernel versions. Canonical patched the issue and released a new Linux kernel update that addresses the problem on all Ubuntu 16.04 LTS systems, as well as Ubuntu 14.04.5 LTS machines.