Making C Less Dangerous

With the kernel written in C, it comes with some worrisome baggage, "undefined" behaviors, and other weaknesses that lead to security flaws and vulnerable infrastructure. Some of these weaknesses related to the design of chipsets and how close C is to machine code, but others are less specific. This presentation will explore the areas where the kernel is changing the C standard, defining undefined behaviors, or otherwise reorganizing things to make C itself less of a hazard. Specifically this will cover removing (and enforcing the lack of) Variable Length Arrays in kernel code, forcing all stack variables to be initialized with a GCC plugin, performing implicit bounds checking with overloaded builtins, handling arithmetic overflows safely, and protecting forward (call) and reverse (return) indirect function calls with CFI under Clang. EVENT: Linux Security Summit 2018 SPEAKER: Kees Cook, Google PERMISSIONS: Original video was published with the Creative Commons Attribution license (reuse allowed). CREDITS: Original video source: https://www.youtube.com/watch?v=XfNt6MsLj0E https://www.youtube.com/watch?v=aDQDL-l1nxw