Debian LTS work, December 2014
This was my first month working on Debian LTS. My first project at Codethink was winding down, so Freexian's Debian LTS initiative was able to hire me via Codethink. I spent all of the assigned 11.5 hours working on an update to the kernel package (linux-2.6, version 2.6.32-48squeeze9).
We had stopped following the upstream stable branch maintained by Willy Tarreau after 2.6.32.60 (released October 2012). Since then, we have only applied specific security fixes and other critical fixes. Raphaël Hertzog and Holger Levsen started to rebase our package on 2.6.32.64 (released November 2014), bringing in a few security fixes we didn't yet have and a larger number of fixes for functional and performance issues.
I spent most of my time reviewing the several hundred changes from the upstream stable branch. I found a number of mistakes that would have caused regressions. Those should all be fixed in the update to linux-2.6, though I did not have nearly enough time for a thorough regression test. I sent my fixes to Willy for inclusion in 2.6.32.65.
I also reviewed and applied fixes for several security flaws in the kernel entry and exit paths. Andy Lutomirski identified and fixed a number of problems upstream, the most serious of which was CVE-2014-9322 (though this is not listed in the changelog because the details weren't yet public). Willy found and backported the upstream fixes for inclusion in 2.6.32.65. I checked that these make sense (so far as I understand this code) and verified that Andy's test cases now have the expected results when run on the new kernel version.
Updated: Added references to Codethink and Freexian.