The fuzzer plugins for libbt-audio-hal-interface
are designed based on the understanding of the source code and tries to achieve the following:
The configuration parameters are not hard-coded, but instead selected based on incoming data. This ensures more code paths are reached by the fuzzers.
Fuzzers assigns values to the following parameters to pass on to libbt-audio-hal-interface:
status
)index
)sessionType
)sessionType_2_1
)param.sampleRate
)param.sampleRate
)a2dpCodecConfig.sample_rate
)param.bitsPerSample
)a2dpCodecConfig.bits_per_sample
)param.channelMode
)a2dpCodecConfig.channel_mode
)sbc.numSubbands
)sbc.allocMethod
)sbc.channelMode
)sbc.blockLength
)aac.objectType
)aac.variableBitRateEnabled
)ldac.qualityIndex
)ldac.channelMode
)codecConfig.codecType
)Parameter | Valid Values | Configured Value |
---|---|---|
status | 0.A2DP_CTRL_ACK_SUCCESS 1.A2DP_CTRL_ACK_FAILURE 2.A2DP_CTRL_ACK_INCALL_FAILURE 3.A2DP_CTRL_ACK_UNSUPPORTED 4.A2DP_CTRL_ACK_PENDING 5.A2DP_CTRL_ACK_DISCONNECT_IN_PROGRESS | Value obtained from FuzzedDataProvider |
index | 0.BTAV_A2DP_CODEC_INDEX_SOURCE_SBC 1.BTAV_A2DP_CODEC_INDEX_SOURCE_AAC 2.BTAV_A2DP_CODEC_INDEX_SOURCE_APTX 3.BTAV_A2DP_CODEC_INDEX_SOURCE_APTX_HD 4.BTAV_A2DP_CODEC_INDEX_SOURCE_LDAC 5.BTAV_A2DP_CODEC_INDEX_SINK_SBC 6.BTAV_A2DP_CODEC_INDEX_SINK_AAC 7.BTAV_A2DP_CODEC_INDEX_SINK_LDAC | Value obtained from FuzzedDataProvider |
sessionType | 0.SessionType::UNKNOWN 1.SessionType::A2DP_SOFTWARE_ENCODING_DATAPATH 2.SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH 3.SessionType::HEARING_AID_SOFTWARE_ENCODING_DATAPATH | Value obtained from FuzzedDataProvider |
sessionType_2_1 | 0.SessionType_2_1::UNKNOWN 1.SessionType_2_1::A2DP_SOFTWARE_ENCODING_DATAPATH 2.SessionType_2_1::A2DP_HARDWARE_OFFLOAD_DATAPATH 3.SessionType_2_1::HEARING_AID_SOFTWARE_ENCODING_DATAPATH 4.SessionType_2_1::LE_AUDIO_SOFTWARE_ENCODING_DATAPATH 5.SessionType_2_1::LE_AUDIO_SOFTWARE_DECODED_DATAPATH 6.SessionType_2_1::LE_AUDIO_HARDWARE_OFFLOAD_ENCODING_DATAPATH 7.SessionType_2_1::LE_AUDIO_HARDWARE_OFFLOAD_DECODING_DATAPATH | Value obtained from FuzzedDataProvider |
param.sampleRate | 0.SampleRate::RATE_UNKNOWN 1.SampleRate::RATE_8000 2.SampleRate::RATE_16000 3.SampleRate::RATE_24000 4.SampleRate::RATE_32000 5.SampleRate::RATE_44100 6.SampleRate::RATE_48000 | Value obtained from FuzzedDataProvider |
param.sampleRate (V2_1) | 0.SampleRate_2_1::RATE_UNKNOWN 1.SampleRate_2_1::RATE_8000 2.SampleRate_2_1::RATE_16000 3.SampleRate_2_1::RATE_24000 4.SampleRate_2_1::RATE_32000 5.SampleRate_2_1::RATE_44100 6.SampleRate_2_1::RATE_48000 | Value obtained from FuzzedDataProvider |
a2dpCodecConfig.sample_rate | 0.BTAV_A2DP_CODEC_SAMPLE_RATE_NONE 1.BTAV_A2DP_CODEC_SAMPLE_RATE_44100 2.BTAV_A2DP_CODEC_SAMPLE_RATE_48000 3.BTAV_A2DP_CODEC_SAMPLE_RATE_88200 4.BTAV_A2DP_CODEC_SAMPLE_RATE_96000 5.BTAV_A2DP_CODEC_SAMPLE_RATE_176400 6.BTAV_A2DP_CODEC_SAMPLE_RATE_192000 7.BTAV_A2DP_CODEC_SAMPLE_RATE_16000 8.BTAV_A2DP_CODEC_SAMPLE_RATE_24000 | Value obtained from FuzzedDataProvider |
param.bitsPerSample | 0.BitsPerSample::BITS_UNKNOWN 1.BitsPerSample::BITS_16 2.BitsPerSample::BITS_24 3.BitsPerSample::BITS_32 | Value obtained from FuzzedDataProvider |
a2dpCodecConfig.bits_per_sample | 0.BTAV_A2DP_CODEC_BITS_PER_SAMPLE_NONE 1.BTAV_A2DP_CODEC_BITS_PER_SAMPLE_16 2.BTAV_A2DP_CODEC_BITS_PER_SAMPLE_24 3.BTAV_A2DP_CODEC_BITS_PER_SAMPLE_32 | Value obtained from FuzzedDataProvider |
param.channelMode | 0.ChannelMode::UNKNOWN 1.ChannelMode::MONO 2.ChannelMode::STEREO | Value obtained from FuzzedDataProvider |
a2dpCodecConfig.channel_mode | 0.BTAV_A2DP_CODEC_CHANNEL_MODE_NONE 1.BTAV_A2DP_CODEC_CHANNEL_MODE_MONO 2.BTAV_A2DP_CODEC_CHANNEL_MODE_STEREO | Value obtained from FuzzedDataProvider |
param.peerMtu | 0.660 1.663 2.883 3.1005 4.1500 | Value obtained from FuzzedDataProvider |
sbc.numSubbands | 0.SbcNumSubbands::SUBBAND_4 1.SbcNumSubbands::SUBBAND_8 | Value obtained from FuzzedDataProvider |
sbc.allocMethod | 0.SbcAllocMethod::ALLOC_MD_S 1.SbcAllocMethod::ALLOC_MD_L | Value obtained from FuzzedDataProvider |
sbc.channelMode | 0.SbcChannelMode::UNKNOWN 1.SbcChannelMode::JOINT_STEREO 2.SbcChannelMode::STEREO 3.SbcChannelMode::DUAL 4.SbcChannelMode::MONO | Value obtained from FuzzedDataProvider |
sbc.blockLength | 0.SbcBlockLength::BLOCKS_4 1.SbcBlockLength::BLOCKS_8 2.SbcBlockLength::BLOCKS_12 3.SbcBlockLength::BLOCKS_16 | Value obtained from FuzzedDataProvider |
aac.objectType | 0.AacObjectType::MPEG2_LC 1.AacObjectType::MPEG4_LC 2.AacObjectType::MPEG4_LTP 3.AacObjectType::MPEG4_SCALABLE | Value obtained from FuzzedDataProvider |
aac.variableBitRateEnabled | 0.AacVariableBitRate::DISABLED 1.AacVariableBitRate::ENABLED | Value obtained from FuzzedDataProvider |
ldac.qualityIndex | 0.LdacQualityIndex::QUALITY_HIGH 1.LdacQualityIndex::QUALITY_MID 2.LdacQualityIndex::QUALITY_LOW 3.LdacQualityIndex::QUALITY_ABR | Value obtained from FuzzedDataProvider |
ldac.channelMode | 0.LdacChannelMode::UNKNOWN 1.LdacChannelMode::STEREO 2.LdacChannelMode::DUAL 3.LdacChannelMode::MONO | Value obtained from FuzzedDataProvider |
codecConfig.codecType | 0.CodecType::APTX 1.CodecType::APTX_HD | Value obtained from FuzzedDataProvider |
This also ensures that the plugins are always deterministic for any given input.
The plugins feed the entire input data to the module. This ensures that the plugins tolerates any kind of input (empty, huge, malformed, etc) and doesn't exit()
on any input and thereby increasing the chance of identifying vulnerabilities.
This describes steps to build libbt_audio_hal_a2dp_encoding_fuzzer, libbt_audio_hal_le_audio_software_fuzzer, libbt_audio_hal_hearing_aid_software_encoding_fuzzer and libbt_audio_hal_client_interface_fuzzer binaries.
Build the fuzzer
$ mm -j$(nproc) libbt_audio_hal_a2dp_encoding_fuzzer $ mm -j$(nproc) libbt_audio_hal_le_audio_software_fuzzer $ mm -j$(nproc) libbt_audio_hal_hearing_aid_software_encoding_fuzzer $ mm -j$(nproc) libbt_audio_hal_client_interface_fuzzer
To run on device
$ adb sync data $ adb shell /data/fuzz/arm64/libbt_audio_hal_a2dp_encoding_fuzzer/libbt_audio_hal_a2dp_encoding_fuzzer $ adb shell /data/fuzz/arm64/libbt_audio_hal_le_audio_software_fuzzer/libbt_audio_hal_le_audio_software_fuzzer $ adb shell /data/fuzz/arm64/libbt_audio_hal_hearing_aid_software_encoding_fuzzer/libbt_audio_hal_hearing_aid_software_encoding_fuzzer $ adb shell /data/fuzz/arm64/libbt_audio_hal_client_interface_fuzzer/libbt_audio_hal_client_interface_fuzzer