47 lines
1.5 KiB
Markdown
47 lines
1.5 KiB
Markdown
# Libfuzzer for libpng, with launcher
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This folder contains an example fuzzer for libpng, using LLMP for fast multi-process fuzzing and crash detection.
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To show off crash detection, we added a `ud2` instruction to the harness, edit harness.cc if you want a non-crashing example.
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It has been tested on Linux.
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In contrast to the normal libfuzzer libpng example, this uses the `launcher` feature, that automatically spawns `n` child processes, and binds them to a free core.
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## Build
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To build this example, run
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```bash
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cargo build --release
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```
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This will build the library with the fuzzer (src/lib.rs) with the libfuzzer compatibility layer and the SanitizerCoverage runtime functions for coverage feedback.
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In addition, it will also build two C and C++ compiler wrappers (bin/libafl_c(libafl_c/xx).rs) that you must use to compile the target.
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Then download libpng, and unpack the archive:
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```bash
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wget https://github.com/glennrp/libpng/archive/refs/tags/v1.6.37.tar.gz
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tar -xvf v1.6.37.tar.gz
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```
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Now compile libpng, using the libafl_cc compiler wrapper:
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```bash
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cd libpng-1.6.37
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./configure
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make CC=../target/release/libafl_cc CXX=../target/release/libafl_cxx -j `nproc`
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```
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You can find the static lib at `libpng-1.6.37/.libs/libpng16.a`.
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Now, we have to build the libfuzzer harness and link all together to create our fuzzer binary.
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```
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cd ..
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./target/release/libafl_cxx ./harness.cc libpng-1.6.37/.libs/libpng16.a -I libpng-1.6.37/ -o fuzzer_libpng -lz -lm
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```
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Afterwards, the fuzzer will be ready to run.
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## Run
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Just run once, the launcher feature should do the rest. |