==========================================================================
Ubuntu Security Notice USN-3522-3
January 10, 2018

linux regression
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 LTS

Summary:

USN-3522-1 introduced a regression in the Linux kernel.

Software Description:
- linux: Linux kernel

Details:

USN-3522-1 fixed a vulnerability in the Linux kernel to address
Meltdown (CVE-2017-5754). Unfortunately, that update introduced
a regression where a few systems failed to boot successfully. This
update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

 Jann Horn discovered that microprocessors utilizing speculative execution
 and indirect branch prediction may allow unauthorized memory reads via
 sidechannel attacks. This flaw is known as Meltdown. A local attacker could
 use this to expose sensitive information, including kernel memory.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 16.04 LTS:
  linux-image-4.4.0-109-generic   4.4.0-109.132
  linux-image-4.4.0-109-lowlatency  4.4.0-109.132
  linux-image-generic             4.4.0.109.114
  linux-image-lowlatency          4.4.0.109.114

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.

References:
  https://www.ubuntu.com/usn/usn-3522-3
  https://www.ubuntu.com/usn/usn-3522-1
  https://launchpad.net/bugs/1741934

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.4.0-109.132