Control Flow Integrity in the Linux Kernel
Explore Control Flow Integrity (CFI) in the Linux kernel through this conference talk from linux.conf.au 2020. Dive into how Android utilizes Clang's CFI implementation for recent phones, the process of upstreaming this technology, and how to implement CFI yourself. Examine the code, data, and symbols Clang inserts to protect indirect calls, kernel modifications required for support, and remaining challenges. Gain insights into attack methods targeting function pointers, understand the differences between forward-edge and backward-edge protection, and witness a demonstration of CFI thwarting a kernel attack. Learn about jump tables, type mangling, implementation ideas, and potential gotchas in CFI adoption. Discover the current upstreaming status, how to identify CFI failures, and engage in thoughtful discussion about the future of kernel security.