android13/frameworks/av/media/codecs/g711/fuzzer

Fuzzer for libstagefright_g711dec decoder

Plugin Design Considerations

The fuzzer plugin for G711 is designed based on the understanding of the codec and tries to achieve the following:

Maximize code coverage

G711 supports two types of decoding:

1. DecodeALaw
2. DecodeMLaw

These two decoder API's are fuzzed separately using g711alaw_dec_fuzzer and g711mlaw_dec_fuzzer respectively.

Maximize utilization of input data

The plugin feeds the entire input data to the codec as expected by decoder API.

Build

This describes steps to build g711alaw_dec_fuzzer and g711mlaw_dec_fuzzer binary.

Android

Steps to build

Build the fuzzer

  $ mm -j$(nproc) g711alaw_dec_fuzzer
  $ mm -j$(nproc) g711mlaw_dec_fuzzer

Steps to run

Create a directory CORPUS_DIR and copy some g711 files to that folder Push this directory to device.

To run on device

  $ adb sync data
  $ adb shell /data/fuzz/arm64/g711alaw_dec_fuzzer/g711alaw_dec_fuzzer CORPUS_DIR
  $ adb shell /data/fuzz/arm64/g711mlaw_dec_fuzzer/g711mlaw_dec_fuzzer CORPUS_DIR

To run on host

  $ $ANDROID_HOST_OUT/fuzz/x86_64/g711alaw_dec_fuzzer/g711alaw_dec_fuzzer CORPUS_DIR
  $ $ANDROID_HOST_OUT/fuzz/x86_64/g711mlaw_dec_fuzzer/g711mlaw_dec_fuzzer CORPUS_DIR

References:

• http://llvm.org/docs/LibFuzzer.html
• https://github.com/google/oss-fuzz