Quantal backported kernel in 12.04.2? What's going on there?

The 12.04.2 and later release ISOs have a Hardware Enablement Stack to allow 12.04 to run on newer hardware.

• https://wiki.ubuntu.com/Kernel/LTSEnablementStack

In an effort to support a wider variety of hardware on an existing LTS release, the 12.04.2 and newer point releases will ship with an updated kernel and X stack by default. These newer hardware enablement stacks will be comprised of the newer kernel and X stacks from Quantal, Raring, and Saucy.

To optionally install it manually (if you've installed from earlier 12.04 release images):

sudo apt-get install --install-recommends \
     linux-generic-lts-quantal \
     xserver-xorg-lts-quantal \
     libgl1-mesa-glx-lts-quantal

and leave out the last two lines for servers (usually no graphics installed).

Here's how support will work for the stacks:

1. If your hardware is supported by 12.04.1, you can install the 12.04.1 it will be supported until 2017 with no extra effort on your part.
2. If you install from a later point release (due to requirements for newer hardware support, or for other reasons), your hardware stack will be upgraded in 2014 (approximately June) to the 14.04 hardware enablement stack. The 14.04 enablement stack will then be supported on 12.04 installs until the 12.04 end of life, in April 2017.

If you want to remove it:

• How to remove Kernel/LTS Enablement Stack?

More info:

• Will Ubuntu point releases include a new Linux kernel?
• http://www.jorgecastro.org/2013/02/19/what-the-lts-enablement-stack-means-for-sysadmins/