selective-instrument

Directed fuzzing on a specific function requires selectively instrumenting target source files using AFL_LLVM_ALLOWLIST. This restricts coverage feedback to defined regions, accelerating path convergence and PoC input generation for vulnerability research.

Selective instrumentation limits fuzzing coverage feedback to specific code regions rather than the entire program. Use it when investigating a security patch or suspected vulnerability to isolate the target function and avoid wasting cycles on irrelevant paths.

Yes, AFL++ can automatically generate characteristic seeds that reach specific code paths during directed fuzzing campaigns. These seeds are collected for use in deeper security analysis and vulnerability research.

Configuring AFL_LLVM_ALLOWLIST involves defining target functions or source files to limit coverage feedback during recompilation. The selective instrument tool applies this allowlist to recompile the project and execute focused fuzzing campaigns.

Selective instrumentation limits path exploration exclusively to allowlisted target regions, ignoring unrelated code paths. This approach is unsuitable for general vulnerability discovery but highly effective for analyzing specific security patches.

Yes, AFL++ toolchain integration is required to manage allowlists and execute instrumented fuzzing campaigns. The toolchain handles recompiling the target binary and managing the directed fuzzing process for security analysis.