The mp_get_count function in drivers/staging/sb105x/sb_pci_mp.c in the Linux kernel before 3.12 does not initialize a certain data structure, which allows local users to obtain sensitive information from kernel stack memory via a TIOCGICOUNT ioctl call.
http://www.openwall.com/lists/oss-security/2013/11/04/22
http://www.ubuntu.com/usn/USN-2069-1
http://www.ubuntu.com/usn/USN-2070-1
http://www.ubuntu.com/usn/USN-2073-1
http://www.ubuntu.com/usn/USN-2075-1
https://github.com/torvalds/linux/commit/a8b33654b1e3b0c74d4a1fed041c9aae50b3c427