drivers/hid/hid-lenovo-tpkbd.c in the Human Interface Device (HID) subsystem in the Linux kernel through 3.11, when CONFIG_HID_LENOVO_TPKBD is enabled, allows physically proximate attackers to cause a denial of service (heap-based out-of-bounds write) via a crafted device.
http://www.ubuntu.com/usn/USN-2023-1
http://www.ubuntu.com/usn/USN-2020-1