Buffer overflow in the exitcode_proc_write function in arch/um/kernel/exitcode.c in the Linux kernel before 3.12 allows local users to cause a denial of service or possibly have unspecified other impact by leveraging root privileges for a write operation.
https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.12.bz2
https://github.com/torvalds/linux/commit/201f99f170df14ba52ea4c52847779042b7a623b
https://euvd.enisa.europa.eu/vulnerability/EUVD-2013-4372
http://www.securityfocus.com/bid/63510