ruzzy

Coverage-guided fuzzing of Ruby C extensions requires the ruzzy gem and a clang-based toolchain with AddressSanitizer and UBSan support to detect crashes and memory safety issues. It automates fuzz campaigns targeting native extension code paths.

Coverage-guided fuzzing for Ruby applications feeds inputs through deterministic harnesses to exercise code paths in a controlled way, revealing memory safety issues and crashes early in the development cycle. It targets both pure Ruby code and native extensions.

AddressSanitizer is required to fuzz Ruby native extensions with this approach. The solution requires a clang-based toolchain with AddressSanitizer and UBSan support and the ruzzy gem to configure and execute the fuzz campaigns.

To set up a Ruby fuzzing harness, write a script that feeds inputs to Ruzzy.fuzz and run it with LD_PRELOAD set to the Ruzzy ASAN path. This validates library gems with native extensions to ensure robustness under malformed inputs.

You can fuzz pure Ruby code as well as Ruby C extensions. The solution targets both to uncover crashes and memory-safety issues, providing deterministic harness support to exercise code paths in a controlled way.

Coverage-guided fuzzing for Ruby requires a clang-based toolchain with AddressSanitizer and UBSan support, limiting it to compatible environments. It also requires writing deterministic harnesses to effectively exercise targeted code paths.