Fuzz introspector
For issues and ideas: https://github.com/ossf/fuzz-introspector/issues

Project functions overview

The following table shows data about each function in the project. The functions included in this table correspond to all functions that exist in the executables of the fuzzers. As such, there may be functions that are from third-party libraries.

For further technical details on the meaning of columns in the below table, please see the Glossary .

Func name Functions filename Args Function call depth Reached by Fuzzers Runtime reached by Fuzzers Combined reached by Fuzzers Fuzzers runtime hit Func lines hit % I Count BB Count Cyclomatic complexity Functions reached Reached by functions Accumulated cyclomatic complexity Undiscovered complexity

Fuzzer details

Fuzzer: fuzz_decode_streaming

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 67 11.1%
gold [1:9] 18 2.98%
yellow [10:29] 8 1.32%
greenyellow [30:49] 5 0.82%
lawngreen 50+ 505 83.7%
All colors 603 100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked Calltree index Parent function Callsite Largest blocked function
30 6 brunsli::internal::dec::State::State() call site: 00006
6 343 brunsli::DecodeHistogramDataSection(brunsli::internal::dec::State*, brunsli::JPEGData*) call site: 00343
4 244 bool brunsli::DecodeLimitedVarint<2ul>(brunsli::internal::dec::VarintState*, brunsli::BrunsliBitReader*, unsigned long) call site: 00244 fprintf
3 40 brunsli::internal::dec::MetadataState::~MetadataState() call site: 00040 __cxa_begin_catch
2 184 BrotliTransformDictionaryWord call site: 00184 Shift
2 188 SafeProcessCommands call site: 00188 SafeDecodeSymbol
2 191 SafeProcessCommands call site: 00191 SafeDecodeSymbol
2 500 brunsli::ProcessSection(brunsli::internal::dec::State*, brunsli::JPEGData*) call site: 00500
2 593 brunsli::(anonymous namespace)::SerializeSection(unsigned char, brunsli::internal::dec::State const&, brunsli::internal::dec::SerializationState*, brunsli::JPEGData const&) call site: 00593
1 50 brunsli::VerifySignature(brunsli::internal::dec::State*) call site: 00050
1 89 brunsli::DecodeHeader(brunsli::internal::dec::State*, brunsli::JPEGData*) call site: 00089
1 102 brunsli::DecodeOriginalJpg(brunsli::internal::dec::State*, brunsli::JPEGData*) call site: 00102

Runtime coverage analysis

Covered functions
295
Functions that are reachable but not covered
69
Reachable functions
461
Percentage of reachable functions covered
85.03%
NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.
Function name source code lines source lines hit percentage hit

Files reached

filename functions hit
/src/brunsli/c/tests/fuzz_decode_streaming.cc 3
/src/brunsli/./c/include/brunsli/jpeg_data_writer.h 1
/src/brunsli/./c/include/brunsli/jpeg_data.h 2
/src/brunsli/c/dec/state.cc 4
/src/brunsli/c/dec/./state_internal.h 19
/src/brunsli/c/dec/./../common/lehmer_code.h 2
/src/brunsli/c/dec/./huffman_decode.h 3
/src/brunsli/c/dec/././ans_decode.h 1
/src/brunsli/c/dec/./././brunsli_input.h 1
/src/brunsli/c/dec/././arith_decode.h 1
/src/brunsli/c/dec/././serialization_state.h 4
/src/brunsli/c/dec/././output_chunk.h 5
/src/brunsli/_deps/brotli-src/c/dec/decode.c 33
/src/brunsli/_deps/brotli-src/c/dec/state.c 5
/src/brunsli/c/dec/brunsli_decode.cc 61
/src/brunsli/_deps/brotli-src/c/dec/bit_reader.c 2
/src/brunsli/_deps/brotli-src/c/common/dictionary.c 1
/src/brunsli/_deps/brotli-src/c/common/transform.c 4
/src/brunsli/_deps/brotli-src/c/dec/huffman.c 3
/src/brunsli/c/dec/bit_reader.cc 7
/src/brunsli/c/dec/../common/lehmer_code.h 4
/src/brunsli/c/dec/../common/././platform.h 1
/src/brunsli/c/common/platform.cc 1
/src/brunsli/c/include/brunsli/jpeg_data.h 1
/src/brunsli/c/common/quant_matrix.cc 1
/src/brunsli/c/dec/././huffman_decode.h 3
/src/brunsli/c/dec/huffman_decode.cc 4
/src/brunsli/c/dec/huffman_table.cc 4
/src/brunsli/c/dec/context_map_decode.cc 3
/src/brunsli/c/dec/histogram_decode.cc 2
/src/brunsli/c/dec/../common/histogram.h 1
/src/brunsli/c/dec/ans_decode.cc 1
/src/brunsli/c/dec/././brunsli_input.h 6
/src/brunsli/c/dec/../common/context.h 10
/src/brunsli/c/dec/./ans_decode.h 3
/src/brunsli/c/dec/./arith_decode.h 2
/src/brunsli/c/dec/../common/./distributions.h 2
/src/brunsli/c/common/predict.cc 2
/src/brunsli/c/common/context.cc 1
/src/brunsli/c/common/lehmer_code.cc 1
/src/brunsli/c/dec/jpeg_data_writer.cc 36
/src/brunsli/c/include/brunsli/jpeg_data_writer.h 1

Fuzzer: fuzz_decode

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 67 11.0%
gold [1:9] 16 2.64%
yellow [10:29] 13 2.15%
greenyellow [30:49] 9 1.49%
lawngreen 50+ 499 82.6%
All colors 604 100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked Calltree index Parent function Callsite Largest blocked function
30 7 brunsli::internal::dec::State::State() call site: 00007
6 344 brunsli::DecodeHistogramDataSection(brunsli::internal::dec::State*, brunsli::JPEGData*) call site: 00344
4 245 bool brunsli::DecodeLimitedVarint<2ul>(brunsli::internal::dec::VarintState*, brunsli::BrunsliBitReader*, unsigned long) call site: 00245 fprintf
3 41 brunsli::internal::dec::MetadataState::~MetadataState() call site: 00041 __cxa_begin_catch
2 185 BrotliTransformDictionaryWord call site: 00185 Shift
2 189 SafeProcessCommands call site: 00189 SafeDecodeSymbol
2 192 SafeProcessCommands call site: 00192 SafeDecodeSymbol
2 594 brunsli::(anonymous namespace)::SerializeSection(unsigned char, brunsli::internal::dec::State const&, brunsli::internal::dec::SerializationState*, brunsli::JPEGData const&) call site: 00594
1 51 brunsli::VerifySignature(brunsli::internal::dec::State*) call site: 00051
1 90 brunsli::DecodeHeader(brunsli::internal::dec::State*, brunsli::JPEGData*) call site: 00090
1 103 brunsli::DecodeOriginalJpg(brunsli::internal::dec::State*, brunsli::JPEGData*) call site: 00103
1 114 brunsli::ParseSection(brunsli::internal::dec::State*) call site: 00114

Runtime coverage analysis

Covered functions
312
Functions that are reachable but not covered
66
Reachable functions
463
Percentage of reachable functions covered
85.75%
NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.
Function name source code lines source lines hit percentage hit

Files reached

filename functions hit
/src/brunsli/c/tests/fuzz_decode.cc 3
/src/brunsli/./c/include/brunsli/jpeg_data_writer.h 1
/src/brunsli/./c/include/brunsli/jpeg_data.h 2
/src/brunsli/c/dec/brunsli_decode.cc 62
/src/brunsli/c/dec/state.cc 4
/src/brunsli/c/dec/./state_internal.h 19
/src/brunsli/c/dec/./../common/lehmer_code.h 2
/src/brunsli/c/dec/./huffman_decode.h 3
/src/brunsli/c/dec/././ans_decode.h 1
/src/brunsli/c/dec/./././brunsli_input.h 1
/src/brunsli/c/dec/././arith_decode.h 1
/src/brunsli/c/dec/././serialization_state.h 4
/src/brunsli/c/dec/././output_chunk.h 5
/src/brunsli/_deps/brotli-src/c/dec/decode.c 33
/src/brunsli/_deps/brotli-src/c/dec/state.c 5
/src/brunsli/_deps/brotli-src/c/dec/bit_reader.c 2
/src/brunsli/_deps/brotli-src/c/common/dictionary.c 1
/src/brunsli/_deps/brotli-src/c/common/transform.c 4
/src/brunsli/_deps/brotli-src/c/dec/huffman.c 3
/src/brunsli/c/dec/bit_reader.cc 7
/src/brunsli/c/dec/../common/lehmer_code.h 4
/src/brunsli/c/dec/../common/././platform.h 1
/src/brunsli/c/common/platform.cc 1
/src/brunsli/c/include/brunsli/jpeg_data.h 1
/src/brunsli/c/common/quant_matrix.cc 1
/src/brunsli/c/dec/././huffman_decode.h 3
/src/brunsli/c/dec/huffman_decode.cc 4
/src/brunsli/c/dec/huffman_table.cc 4
/src/brunsli/c/dec/context_map_decode.cc 3
/src/brunsli/c/dec/histogram_decode.cc 2
/src/brunsli/c/dec/../common/histogram.h 1
/src/brunsli/c/dec/ans_decode.cc 1
/src/brunsli/c/dec/././brunsli_input.h 6
/src/brunsli/c/dec/../common/context.h 10
/src/brunsli/c/dec/./ans_decode.h 3
/src/brunsli/c/dec/./arith_decode.h 2
/src/brunsli/c/dec/../common/./distributions.h 2
/src/brunsli/c/common/predict.cc 2
/src/brunsli/c/common/context.cc 1
/src/brunsli/c/common/lehmer_code.cc 1
/src/brunsli/c/dec/jpeg_data_writer.cc 36
/src/brunsli/c/include/brunsli/jpeg_data_writer.h 1

Fuzz engine guidance

This sections provides heuristics that can be used as input to a fuzz engine when running a given fuzz target. The current focus is on providing input that is usable by libFuzzer.

/src/brunsli/c/tests/fuzz_decode_streaming.cc

Dictionary

Use this with the libFuzzer -dict=DICT.file flag


Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['brunsli::internal::dec::State::State()', 'brunsli::DecodeHistogramDataSection(brunsli::internal::dec::State*, brunsli::JPEGData*)', 'bool brunsli::DecodeLimitedVarint<2ul>(brunsli::internal::dec::VarintState*, brunsli::BrunsliBitReader*, unsigned long)', 'brunsli::internal::dec::MetadataState::~MetadataState()', 'BrotliTransformDictionaryWord', 'SafeProcessCommands', 'brunsli::ProcessSection(brunsli::internal::dec::State*, brunsli::JPEGData*)', 'brunsli::(anonymous namespace)::SerializeSection(unsigned char, brunsli::internal::dec::State const&, brunsli::internal::dec::SerializationState*, brunsli::JPEGData const&)', 'brunsli::VerifySignature(brunsli::internal::dec::State*)']

/src/brunsli/c/tests/fuzz_decode.cc

Dictionary

Use this with the libFuzzer -dict=DICT.file flag


Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['brunsli::internal::dec::State::State()', 'brunsli::DecodeHistogramDataSection(brunsli::internal::dec::State*, brunsli::JPEGData*)', 'bool brunsli::DecodeLimitedVarint<2ul>(brunsli::internal::dec::VarintState*, brunsli::BrunsliBitReader*, unsigned long)', 'brunsli::internal::dec::MetadataState::~MetadataState()', 'BrotliTransformDictionaryWord', 'SafeProcessCommands', 'brunsli::(anonymous namespace)::SerializeSection(unsigned char, brunsli::internal::dec::State const&, brunsli::internal::dec::SerializationState*, brunsli::JPEGData const&)', 'brunsli::VerifySignature(brunsli::internal::dec::State*)', 'brunsli::DecodeHeader(brunsli::internal::dec::State*, brunsli::JPEGData*)']

Files and Directories in report

This section shows which files and directories are considered in this report. The main reason for showing this is fuzz introspector may include more code in the reasoning than is desired. This section helps identify if too many files/directories are included, e.g. third party code, which may be irrelevant for the threat model. In the event too much is included, fuzz introspector supports a configuration file that can exclude data from the report. See the following link for more information on how to create a config file: link

Files in report

Source file Reached by Covered by
[] []
/src/brunsli/c/tests/fuzz_decode.cc ['fuzz_decode'] ['fuzz_decode']
/src/brunsli/c/dec/././serialization_state.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/././arith_decode.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/./state_internal.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/_deps/brotli-src/c/dec/state.c ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/brunsli_decode.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/../common/././platform.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/../common/histogram.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/jpeg_data_writer.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/_deps/brotli-src/c/common/platform.c [] []
/src/brunsli/c/dec/../common/context.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/_deps/brotli-src/c/dec/huffman.c ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/./c/include/brunsli/jpeg_data_writer.h ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/tests/test_utils.cc [] []
/src/brunsli/c/dec/././brunsli_input.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/./arith_decode.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/./huffman_decode.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/./c/include/brunsli/jpeg_data.h ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/common/quant_matrix.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/include/brunsli/jpeg_data_writer.h ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/././huffman_decode.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/state.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/common/././distributions.h [] []
/src/brunsli/c/tests/fuzz_decode_streaming.cc ['fuzz_decode_streaming'] ['fuzz_decode_streaming']
/src/brunsli/_deps/brotli-src/c/common/transform.c ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/common/platform.cc ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/./././brunsli_input.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/_deps/brotli-src/c/dec/bit_reader.c ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/./ans_decode.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/../common/lehmer_code.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/dec/../common/./distributions.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/include/brunsli/jpeg_data.h ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/tests/./test_utils.h [] []
/src/brunsli/c/common/predict.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/_deps/brotli-src/c/dec/decode.c ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/././output_chunk.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/usr/local/bin/../include/c++/v1/string [] []
/usr/local/bin/../include/c++/v1/stdexcept [] []
/src/brunsli/c/dec/huffman_table.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/_deps/brotli-src/c/common/dictionary.c ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/histogram_decode.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/././ans_decode.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/common/context.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/context_map_decode.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/bit_reader.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/./../common/lehmer_code.h ['fuzz_decode_streaming', 'fuzz_decode'] []
/src/brunsli/c/common/lehmer_code.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/huffman_decode.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']
/src/brunsli/c/dec/ans_decode.cc ['fuzz_decode_streaming', 'fuzz_decode'] ['fuzz_decode_streaming', 'fuzz_decode']

Directories in report

Directory
/src/brunsli/c/dec/././
/src/brunsli/c/dec/./././
/src/brunsli/c/tests/./
/src/brunsli/c/dec/./../common/
/src/brunsli/_deps/brotli-src/c/common/
/src/brunsli/c/dec/
/src/brunsli/c/dec/../common/./
/usr/local/bin/../include/c++/v1/
/src/brunsli/c/include/brunsli/
/src/brunsli/./c/include/brunsli/
/src/brunsli/c/common/././
/src/brunsli/c/tests/
/src/brunsli/c/dec/./
/src/brunsli/_deps/brotli-src/c/dec/
/src/brunsli/c/dec/../common/././
/src/brunsli/c/dec/../common/
/src/brunsli/c/common/