High level conclusions

Fuzzers reach 53.21% of cyclomatic complexity.

Fuzzers reach 45.84% of all functions.

Fuzzer dr_flac_fuzzer is blocked:

The runtime code coverage of dr_flac_fuzzer covers 0.0% of its statically reachable code. This means there is some place that blocks the fuzzer to continue exploring more code at run time.

Reachability and coverage overview

Functions statically reachable by fuzzers

193 / 421

Cyclomatic complexity statically reachable by fuzzers

2042 / 3837

Runtime code coverage of functions

105 / 421

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: dr_flac_fuzzer

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	251	100.%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	0	0.0%
All colors	251	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
250	0	EP	call site: 00000	drflac_open_memory

Runtime coverage analysis

Covered functions

0

Functions that are reachable but not covered

89

Reachable functions

89

Percentage of reachable functions covered

0.0%

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
flac/dr_flac_fuzzer.cc	1
flac/../../dr_flac.h	45

Fuzzer: dr_mp3_fuzzer

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	32	17.8%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	147	82.1%
All colors	179	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
17	132	drmp3_decode_next_frame_ex__memory(drmp3*, short*, drmp3dec_frame_info*, unsigned char const**)	call site: 00132	drmp3dec_decode_frame
11	7	drmp3_init_internal(drmp3*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drmp3_seek_origin), unsigned int (*)(void*, long long*), void (*)(void*, drmp3_metadata const*), void*, void*, drmp3_allocation_callbacks const*)	call site: 00007	drmp3_malloc
1	115	drmp3dec_decode_frame	call site: 00115
1	154	drmp3_init_internal(drmp3*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drmp3_seek_origin), unsigned int (*)(void*, long long*), void (*)(void*, drmp3_metadata const*), void*, void*, drmp3_allocation_callbacks const*)	call site: 00154
1	162	drmp3__on_seek_memory(void*, int, drmp3_seek_origin)	call site: 00162	__assert_fail
1	176	LLVMFuzzerTestOneInput	call site: 00176	fclose

Runtime coverage analysis

Covered functions

63

Functions that are reachable but not covered

20

Reachable functions

139

Percentage of reachable functions covered

85.61%

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
mp3/dr_mp3_fuzzer.cc	1
mp3/../../dr_mp3.h	72

Fuzzer: dr_wav_fuzzer

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	234	63.0%
gold	[1:9]	1	0.26%
yellow	[10:29]	1	0.26%
greenyellow	[30:49]	2	0.53%
lawngreen	50+	133	35.8%
All colors	371	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
199	73	drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)	call site: 00073	drwav_fourcc_equal
8	274	drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)	call site: 00274	drwav_free
7	361	LLVMFuzzerTestOneInput	call site: 00361	__assert_fail
2	36	drwav__read_chunk_header(unsigned long (*)(void*, void*, unsigned long), void*, drwav_container, unsigned long long*, drwav_chunk_header*)	call site: 00036	drwav_bytes_to_u64
1	9	drwav__on_seek_memory(void*, int, drwav_seek_origin)	call site: 00009	__assert_fail
1	46	drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)	call site: 00046
1	52	drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)	call site: 00052
1	56	drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)	call site: 00056
1	71	drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)	call site: 00071
1	283	drwav_free	call site: 00283
1	285	drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)	call site: 00285	drwav_free
1	295	LLVMFuzzerTestOneInput	call site: 00295	drwav_read_pcm_frames

Runtime coverage analysis

Covered functions

68

Functions that are reachable but not covered

66

Reachable functions

132

Percentage of reachable functions covered

50.0%

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
wav/dr_wav_fuzzer.cc	1
wav/../../dr_wav.h	76

Optimal target analysis

Remaining optimal interesting functions

The following table shows a list of functions that are optimal targets. Optimal targets are identified by finding the functions that in combination, yield a high code coverage.

Func name	Functions filename	Arg count	Args	Function depth	hitcount	instr count	bb count	cyclomatic complexity	Reachable functions	Incoming references	total cyclomatic complexity	Unreached complexity
drwav_open_file_and_read_pcm_frames_s32_w	/src/dr_libs/tests/wav/../../dr_wav.h	5	['N/A', 'N/A', 'N/A', 'N/A', 'N/A']	10	0	83	15	6	169	0	1042	291
drflac_seek_to_pcm_frame	/src/dr_libs/tests/flac/../../dr_flac.h	2	['N/A', 'size_t']	14	0	325	49	20	92	1	772	266
drflac_open_file_and_read_pcm_frames_f32	/src/dr_libs/tests/flac/../../dr_flac.h	5	['N/A', 'N/A', 'N/A', 'N/A', 'N/A']	12	0	85	15	6	101	0	962	219
drmp3_open_file_and_read_pcm_frames_s16	/src/dr_libs/tests/mp3/../../dr_mp3.h	4	['N/A', 'N/A', 'N/A', 'N/A']	12	0	41	6	3	147	0	649	175
drwav_init_memory_write_sequential_pcm_frames	/src/dr_libs/tests/wav/../../dr_wav.h	6	['N/A', 'N/A', 'N/A', 'N/A', 'size_t', 'N/A']	8	0	50	6	3	44	0	146	137
drwav_open_file_and_read_pcm_frames_f32	/src/dr_libs/tests/wav/../../dr_wav.h	5	['N/A', 'N/A', 'N/A', 'N/A', 'N/A']	10	0	83	15	6	168	0	1036	123
drmp3_calculate_seek_points	/src/dr_libs/tests/mp3/../../dr_mp3.h	3	['N/A', 'N/A', 'N/A']	14	0	391	52	18	130	0	429	75
drwav_write_pcm_frames	/src/dr_libs/tests/wav/../../dr_wav.h	3	['N/A', 'size_t', 'N/A']	9	0	39	6	3	56	0	157	60
drflac_open_memory_and_read_pcm_frames_s16	/src/dr_libs/tests/flac/../../dr_flac.h	6	['N/A', 'size_t', 'N/A', 'N/A', 'N/A', 'N/A']	12	0	88	15	6	92	0	813	55

Implementing fuzzers that target the above functions will improve reachability such that it becomes:

Functions statically reachable by fuzzers

324 / 421

Cyclomatic complexity statically reachable by fuzzers

3411 / 3837

All functions overview

If you implement fuzzers for these functions, the status of all functions in the project will be:

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

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.

flac/dr_flac_fuzzer.cc

Dictionary

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

mp3/dr_mp3_fuzzer.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=['drmp3_decode_next_frame_ex__memory(drmp3*, short*, drmp3dec_frame_info*, unsigned char const**)', 'drmp3_init_internal(drmp3*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drmp3_seek_origin), unsigned int (*)(void*, long long*), void (*)(void*, drmp3_metadata const*), void*, void*, drmp3_allocation_callbacks const*)', 'drmp3dec_decode_frame', 'drmp3_init_internal(drmp3*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drmp3_seek_origin), unsigned int (*)(void*, long long*), void (*)(void*, drmp3_metadata const*), void*, void*, drmp3_allocation_callbacks const*)', 'drmp3__on_seek_memory(void*, int, drmp3_seek_origin)', 'LLVMFuzzerTestOneInput']

wav/dr_wav_fuzzer.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=['drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)', 'drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)', 'LLVMFuzzerTestOneInput', 'drwav__read_chunk_header(unsigned long (*)(void*, void*, unsigned long), void*, drwav_container, unsigned long long*, drwav_chunk_header*)', 'drwav__on_seek_memory(void*, int, drwav_seek_origin)', 'drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)', 'drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)', 'drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)', 'drwav_init__internal(drwav*, unsigned long long (*)(void*, unsigned long (*)(void*, void*, unsigned long), unsigned int (*)(void*, int, drwav_seek_origin), void*, drwav_chunk_header const*, drwav_container, drwav_fmt const*), void*, unsigned int)', 'drwav_free']

This section shows analysis of runtime coverage data.

For futher technical details on how this section is generated, please see the Glossary .

Complex functions with low coverage

Func name	Function total lines	Lines covered at runtime	percentage covered	Reached by fuzzers
drwav_read_raw	48	19	39.58%	['dr_wav_fuzzer']
drwav__read_chunk_header(unsignedlong(*)(void*,void*,unsignedlong),void*,drwav_container,unsignedlonglong*,drwav_chunk_header*)	33	15	45.45%	['dr_wav_fuzzer']

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/dr_libs/tests/wav/dr_wav_fuzzer.cc	['dr_wav_fuzzer']	['dr_wav_fuzzer']
/src/dr_libs/tests/flac/dr_flac_fuzzer.cc	['dr_flac_fuzzer']	[]
/src/dr_libs/tests/wav/../../dr_wav.h	['dr_wav_fuzzer']	[]
/src/dr_libs/tests/flac/../../dr_flac.h	['dr_flac_fuzzer']	[]
/src/dr_libs/tests/mp3/dr_mp3_fuzzer.cc	['dr_mp3_fuzzer']	['dr_mp3_fuzzer']
/src/dr_libs/tests/mp3/../../dr_mp3.h	['dr_mp3_fuzzer']	[]

Directories in report

Directory
/src/dr_libs/tests/flac/../../
/src/dr_libs/tests/wav/
/src/dr_libs/tests/mp3/../../
/src/dr_libs/tests/wav/../../
/src/dr_libs/tests/flac/
/src/dr_libs/tests/mp3/