The ATM implementation in the Linux kernel before 3.6 does not initialize certain structures, which allows local users to obtain sensitive information from kernel stack memory via a crafted application.
https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.6.bz2
https://github.com/torvalds/linux/commit/e862f1a9b7df4e8196ebec45ac62295138aa3fc2
https://github.com/torvalds/linux/commit/3c0c5cfdcd4d69ffc4b9c0907cec99039f30a50a
http://www.ubuntu.com/usn/USN-1808-1
http://www.ubuntu.com/usn/USN-1805-1
http://www.openwall.com/lists/oss-security/2013/03/05/13