Fuzz Testing

This directory contains fuzz tests for gix-pack using cargo-fuzz.

Running Fuzz Tests

Prerequisites

• Nightly Rust toolchain: rustup install nightly
• cargo-fuzz: cargo install cargo-fuzz

Targets

• data_file: exercises .pack parsing, checksum verification, entry lookup, and entry decoding.
• index_file: exercises .idx parsing, checksum verification, lookups, prefix lookups, and iteration.
• multi_index_file: exercises multi-pack-index parsing, checksum verification, lookups, prefix lookups, and iteration.

Running a specific target

cargo +nightly fuzz run data_file -- -max_total_time=60
cargo +nightly fuzz run index_file -- -max_total_time=60
cargo +nightly fuzz run multi_index_file -- -max_total_time=60

Running all targets

for target in data_file index_file multi_index_file; do
    cargo +nightly fuzz run "$target" -- -max_total_time=60
done

Artifact Reproducers

The artifacts/<target> directories contain minimized reproducer inputs produced by libFuzzer or Google OSS-Fuzz.

The integration test module fuzzed reads every regular file in the populated artifact directories and runs it through the parser under test. This lets cargo test -p gix-pack fuzzed reproduce known fuzz failures without starting a fuzzing session.

When OSS-Fuzz reports a new failure, place the minimized testcase in the matching artifacts/<target> directory, then run cargo test -p gix-pack fuzzed. To confirm it against the original harness, run cargo fuzz run <target> artifacts/<target>/<reproducer> from this directory.