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| author | vanhauser-thc <vh@thc.org> | 2021-07-12 15:56:25 +0200 |
|---|---|---|
| committer | vanhauser-thc <vh@thc.org> | 2021-07-12 15:56:37 +0200 |
| commit | d16d8dbb8511ad227fdeb33eb5a10914d9ad7bd9 (patch) | |
| tree | 292a2f6a76bfdad7d06b033f79a18608e07b2459 | |
| parent | fc3d7e821c94a87483906c4cf1c84f1eff01e036 (diff) | |
| download | afl++-d16d8dbb8511ad227fdeb33eb5a10914d9ad7bd9.tar.gz | |
update faq
| -rw-r--r-- | docs/FAQ.md | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/docs/FAQ.md b/docs/FAQ.md index ab0abe6c..0f447044 100644 --- a/docs/FAQ.md +++ b/docs/FAQ.md @@ -188,13 +188,7 @@ Four steps are required to do this and it also requires quite some knowledge of coding and/or disassembly and is effectively possible only with afl-clang-fast PCGUARD and afl-clang-lto LTO instrumentation. - 1. First step: Identify which edge ID numbers are unstable - - run the target with `export AFL_DEBUG=1` for a few minutes then terminate. - The out/fuzzer_stats file will then show the edge IDs that were identified - as unstable. - - 2. Second step: Find the responsible function(s). + 1. First step: Instrument to be able to find the responsible function(s). a) For LTO instrumented binaries this can be documented during compile time, just set `export AFL_LLVM_DOCUMENT_IDS=/path/to/a/file`. @@ -217,6 +211,14 @@ afl-clang-fast PCGUARD and afl-clang-lto LTO instrumentation. recompile with the two mentioned above. This is just for identifying the functions that have unstable edges. + 2. Second step: Identify which edge ID numbers are unstable + + run the target with `export AFL_DEBUG=1` for a few minutes then terminate. + The out/fuzzer_stats file will then show the edge IDs that were identified + as unstable in the `var_bytes` entry. You can match these numbers + directly to the data you created in the first step. + Now you know which functions are responsible for the instability + 3. Third step: create a text file with the filenames/functions Identify which source code files contain the functions that you need to |