Biblio

Fuzzing is a promising method for discovering vulnerabilities. Recently, various techniques are developed to improve the efficiency of fuzzing, and impressive gains are observed in evaluation results. However, evaluation is complex, as many factors affect the results, for example, test suites, baseline and metrics. Even more, most experiment setups are lab-oriented, lacking industrial settings such as large code-base and parallel runs. The correlation between the academic evaluation results and the bug-finding ability in real industrial settings has not been sufficiently studied. In this paper, we test representative fuzzing techniques to reveal their efficiency in industrial settings. First, we apply typical fuzzers on academic widely used small projects from LAVAM suite. We also apply the same fuzzers on large practical projects from Google's fuzzer-test-suite, which is rarely used in academic settings. Both experiments are performed in both single and parallel run. By analyzing the results, we found that most optimizations working well on LAVA-M suite fail to achieve satisfying results on Google's fuzzer-test-suite (e.g. compared to AFL, QSYM detects 82x more synthesized bugs in LAVA-M, but only detects 26% real bugs in Google's fuzzer-test-suite), and the original AFL even outperforms most academic optimization variants in industry widely used parallel runs (e.g. AFL covers 13% more paths than AFLFast). Then, we summarize common pitfalls of those optimizations, analyze the corresponding root causes, and propose potential directions such as orchestrations and synchronization to overcome the problems. For example, when running in parallel on those large practical projects, the proposed horizontal orchestration could cover 36%-82% more paths, and discover 46%-150% more unique crashes or bugs, compared to fuzzers such as AFL, FairFuzz and QSYM.

When a fault occurs in power grid, the analytic model for power grid fault diagnosis could generate multiple solutions under one or more protective relays (PRs) and/or circuit breakers (CBs) malfunctioning, and/or one or more their alarm information failing. Hence, this paper, calling the electrical quantities, presents an optimal solution discrimination method, which determines the optimal solution by constructing the electrical criteria of suspicious faulty components. Furthermore, combining the established electrical criteria with the existing analytic model, a hierarchical fault diagnosis mode is proposed. It uses the analytic model for the first level diagnosis based on the switching quantities. Thereafter, aiming at multiple solutions, it applies the electrical criteria for the second level diagnosis to determine the diagnostic result. Finally, the examples of fault diagnosis demonstrate the feasibility and effectiveness of the developed method.

Application Programming Interfaces (APIs) usually have usage constraints, such as call conditions or call orders. Incorrect usage of these constraints, called API misuse, will result in system crashes, bugs, and even security problems. It is crucial to detect such misuses early in the development process. Though many approaches have been proposed over the last years, recent studies show that API misuses are still prevalent, especially the ones specific to individual projects. In this paper, we strive to improve current API-misuse detection capability for large-scale C programs. First, We propose IMSpec, a lightweight domain-specific language enabling developers to specify API usage constraints in three different aspects (i.e., parameter validation, error handling, and causal calling), which are the majority of API-misuse bugs. Then, we have tailored a constraint guided static analysis engine to automatically parse IMSpec rules and detect API-misuse bugs with rich semantics. We evaluate our approach on widely used benchmarks and real-world projects. The results show that our easily extensible approach performs better than state-of-the-art tools. We also discover 19 previously unknown bugs in real-world open-source projects, all of which have been confirmed by the corresponding developers.