A Binary-level Thread Sanitizer or Why Sanitizing on the Binary Level is Hard

Dynamic software testing methods, such as fuzzing, have become a popular and effective method for detecting many types of faults in programs. While most research focuses on targets for which source code is available, much of the software used in practice is only available as closed source. Testing software without having access to source code forces a user to resort to binary-only testing methods, which are typically slower and lack support for crucial features, such as advanced bug oracles in the form of sanitizers, i. e., dynamic methods to detect faults based on undefined or suspicious behavior. Almost all existing sanitizers work by injecting instrumentation at compile time, requiring access to the target's source code. In this paper, we systematically identify the key challenges of applying sanitizers to binary-only targets. As a result of our analysis, we present the design and implementation of BINTSAN, an approach to realize the data race detector TSAN targeting binary-only Linux x86-64 targets. We systematically evaluate BINTSAN for correctness, effectiveness, and performance. We find that our approach has a runtime overhead of only 15% compared to source-based TSAN. Compared to existing binary solutions, our approach has better performance (up to 5.0× performance improvement) and precision, while preserving compatibility with the compilerbased TSAN.