High level conclusions

Fuzzer fuzz_bundle is blocked:

The runtime code coverage of fuzz_bundle covers 15.59% of its statically reachable code. This means there is some place that blocks the fuzzer to continue exploring more code at run time.

Fuzzer fuzz_configfile is blocked:

The runtime code coverage of fuzz_configfile covers 22.85% of its statically reachable code. This means there is some place that blocks the fuzzer to continue exploring more code at run time.

Fuzzer fuzz_object_store is blocked:

The runtime code coverage of fuzz_object_store covers 27.27% 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

88 / 1773

Cyclomatic complexity statically reachable by fuzzers

319 / 6233

Runtime code coverage of functions

302 / 1773

Warning: The number of runtime covered functions are larger than the number of reachable functions. This means that Fuzz Introspector found there are more functions covered at runtime than what is considered reachable based on the static analysis. This is a limitation in the analysis as anything covered at runtime is by definition reachable by the fuzzers.
This is likely due to a limitation in the static analysis. In this case, the count of functions covered at runtime is the true value, which means this is what should be considered "achieved" by the fuzzer.

Use the project functions table below to query all functions that were not covered at runtime.

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: fuzz_repo

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	78	30.5%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	177	69.4%
All colors	255	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
16	211	dulwich.config.StackedConfig.default_backends	call site: 00211	dulwich.config.get_win_system_paths
13	158	dulwich.repo.Repo.__init__	call site: 00158	dulwich.object_store.DiskObjectStore.from_config
9	173	dulwich.repo.Repo.__init__	call site: 00173	dulwich.repo.parse_graftpoints
7	37	dulwich.repo.Repo.__init__	call site: 00037	os.path.isfile
6	45	dulwich.repo.Repo.__init__	call site: 00045	dulwich.repo.read_gitfile
4	56	dulwich.repo.Repo.get_named_file	call site: 00056	os.path.join
3	10	dulwich.repo.Repo.init	call site: 00010	ctypes.WINFUNCTYPE
3	233	dulwich.repo.Repo._init_maybe_bare	call site: 00233	test_utils.EnhancedFuzzedDataProvider.ConsumeRandomBytes
2	5	dulwich.repo.Repo.init	call site: 00005	os.fsdecode
2	151	dulwich.config.ConfigDict._check_section_and_name	call site: 00151	subsection.encode
2	245	...dulwich.fuzzing.fuzz-targets.fuzz_repo.TestOneInput	call site: 00245	repo.do_commit
2	252	...dulwich.fuzzing.fuzz-targets.fuzz_repo.TestOneInput	call site: 00252	test_utils.EnhancedFuzzedDataProvider.ConsumeRandomInt

Runtime coverage analysis

Covered functions

334

Functions that are reachable but not covered

79

Reachable functions

115

Percentage of reachable functions covered

31.3%

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.

Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
/	1
...dulwich.fuzzing.fuzz-targets.fuzz_repo	17
dulwich.repo	44
dulwich.object_store	6
dulwich.refs	3
dulwich.config	58
dulwich.objects	3
dulwich.hooks	2

Fuzzer: fuzz_object_store

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	51	64.5%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	28	35.4%
All colors	79	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
24	54	dulwich.objects.S_ISGITLINK	call site: 00054	dulwich.patch.write_object_diff.content
23	30	...dulwich.fuzzing.fuzz-targets.fuzz_object_store.TestOneInput	call site: 00030	dulwich.patch.write_tree_diff
2	0	EP	call site: 00000	dulwich.repo.MemoryRepo.__init__
2	11	dulwich.config.ConfigFile.__init__	call site: 00011	dulwich.objects.ShaFile.from_string

Runtime coverage analysis

Covered functions

333

Functions that are reachable but not covered

32

Reachable functions

44

Percentage of reachable functions covered

27.27%

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.

Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
/	1
...dulwich.fuzzing.fuzz-targets.fuzz_object_store	12
dulwich.repo	4
dulwich.refs	2
dulwich.object_store	1
dulwich.config	2
dulwich.objects	4
dulwich.patch	23

Fuzzer: fuzz_configfile

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	3	3.94%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	73	96.0%
All colors	76	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
2	0	EP	call site: 00000	dulwich.config.ConfigFile.from_file
1	5	dulwich.config.ConfigFile.__init__	call site: 00005	included_paths.copy

Runtime coverage analysis

Covered functions

334

Functions that are reachable but not covered

27

Reachable functions

35

Percentage of reachable functions covered

22.86%

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.

Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
/	1
...dulwich.fuzzing.fuzz-targets.fuzz_configfile	3
dulwich.config	31

Fuzzer: fuzz_bundle

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	123	66.8%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	61	33.1%
All colors	184	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
53	12	dulwich.pack.pack_objects_to_data	call site: 00012	dulwich.pack.deltify_pack_objects
20	84	dulwich.pack.PackChunkGenerator._pack_data_chunks	call site: 00084	dulwich.pack.pack_object_chunks
16	166	...dulwich.fuzzing.fuzz-targets.fuzz_bundle.TestOneInput	call site: 00166	dulwich.bundle._read_bundle
10	134	dulwich.pack.read_pack_header	call site: 00134	dulwich.pack.PackStreamReader._buf_len
6	66	dulwich.pack.pack_objects_to_data	call site: 00066	dulwich.pack.full_unpacked_object
6	126	dulwich.pack.read_pack_header	call site: 00126	dulwich.contrib.swift.SwiftPackReader.read
6	159	dulwich.bundle.write_bundle	call site: 00159	dulwich.pack.write_pack_data
2	6	...dulwich.fuzzing.fuzz-targets.fuzz_bundle.TestOneInput	call site: 00006	test_utils.EnhancedFuzzedDataProvider.ConsumeRandomString
1	73	dulwich.pack.write_pack_objects	call site: 00073	dulwich.pack.PackChunkGenerator.__iter__
1	77	dulwich.pack.PackChunkGenerator.__init__	call site: 00077	.len
1	113	dulwich.pack.PackData.from_file	call site: 00113	dulwich.file.GitFile
1	118	dulwich.file._GitFile.__init__	call site: 00118	.getattr

Runtime coverage analysis

Covered functions

334

Functions that are reachable but not covered

92

Reachable functions

109

Percentage of reachable functions covered

15.6%

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.

Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
/	1
...dulwich.fuzzing.fuzz-targets.fuzz_bundle	13
dulwich.pack	73
dulwich.file	8
dulwich.contrib.swift	6
dulwich.bundle	19

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
dulwich.repo.Repo.clone	dulwich.repo	10	['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A']	8	0	12	8	6	347	0	1146	685
dulwich.porcelain.pull	dulwich.porcelain	11	['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A']	8	0	5	8	6	291	1	970	639
dulwich.cli.cmd_filter_branch.run	dulwich.cli	2	['N/A', 'N/A']	10	0	19	11	7	272	0	906	410
dulwich.client.GitClient.clone	dulwich.client	13	['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A']	8	0	10	12	8	353	0	1173	327
dulwich.porcelain.checkout	dulwich.porcelain	4	['N/A', 'N/A', 'N/A', 'N/A']	10	0	11	13	8	247	2	829	257
dulwich.object_store.DiskObjectStore._complete_pack	dulwich.object_store	6	['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A']	10	0	13	3	4	143	2	451	213
dulwich.client.TraditionalGitClient.send_pack	dulwich.client	5	['N/A', 'N/A', 'N/A', 'N/A', 'N/A']	6	0	8	9	7	116	0	380	168

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

Functions statically reachable by fuzzers

450 / 1773

Cyclomatic complexity statically reachable by fuzzers

1701 / 6233

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.

/src/dulwich/fuzzing/fuzz-targets/fuzz_repo.py

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=['dulwich.config.StackedConfig.default_backends', 'dulwich.repo.Repo.__init__', 'dulwich.repo.Repo.get_named_file', 'dulwich.repo.Repo.init', 'dulwich.repo.Repo._init_maybe_bare', 'dulwich.config.ConfigDict._check_section_and_name']

/src/dulwich/fuzzing/fuzz-targets/fuzz_object_store.py

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=['dulwich.objects.S_ISGITLINK', '...dulwich.fuzzing.fuzz-targets.fuzz_object_store.TestOneInput', 'dulwich.config.ConfigFile.__init__']

/src/dulwich/fuzzing/fuzz-targets/fuzz_configfile.py

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=['dulwich.config.ConfigFile.__init__']

/src/dulwich/fuzzing/fuzz-targets/fuzz_bundle.py

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=['dulwich.pack.pack_objects_to_data', 'dulwich.pack.PackChunkGenerator._pack_data_chunks', '...dulwich.fuzzing.fuzz-targets.fuzz_bundle.TestOneInput', 'dulwich.pack.read_pack_header', 'dulwich.bundle.write_bundle', 'dulwich.pack.write_pack_objects', 'dulwich.pack.PackChunkGenerator.__init__']

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
dulwich.repo.Repo.stage	39	21	53.84%	['fuzz_object_store', 'fuzz_repo', 'fuzz_configfile', 'fuzz_bundle']
dulwich.repo.Repo.clone	40	0	0.0%	[]
repo.refs.read_ref	44	23	52.27%	['fuzz_object_store', 'fuzz_repo', 'fuzz_configfile', 'fuzz_bundle']
dulwich.config.ConfigFile._evaluate_hasconfig_condition	34	0	0.0%	[]
dulwich.objects.Tag._deserialize	31	0	0.0%	[]
dulwich.objects.parse_commit	45	5	11.11%	['fuzz_object_store', 'fuzz_repo', 'fuzz_configfile', 'fuzz_bundle']
dulwich.objects.Commit.check	32	0	0.0%	[]
dulwich.object_store.DiskObjectStore._complete_pack	31	0	0.0%	[]
dulwich.object_store.DiskObjectStore.write_commit_graph	33	0	0.0%	[]
dulwich.pack.read_zlib_chunks	33	0	0.0%	[]
dulwich.pack.unpack_object	32	0	0.0%	[]
dulwich.pack.PackChunkGenerator._pack_data_chunks	38	10	26.31%	['fuzz_object_store', 'fuzz_repo', 'fuzz_configfile', 'fuzz_bundle']
dulwich.pack.apply_delta.get_delta_header_size	44	0	0.0%	[]
dulwich.pack.write_pack_index_v3	37	0	0.0%	[]
dulwich.refs.DiskRefsContainer.set_if_equals	33	0	0.0%	[]
dulwich.refs.DiskRefsContainer.remove_if_equals	34	0	0.0%	[]
dulwich.index._decompress_path_from_stream	47	19	40.42%	['fuzz_object_store', 'fuzz_repo', 'fuzz_configfile', 'fuzz_bundle']
dulwich.index.read_index_dict_with_version	42	18	42.85%	['fuzz_object_store', 'fuzz_repo', 'fuzz_configfile', 'fuzz_bundle']
dulwich.index.update_working_tree	87	0	0.0%	[]
dulwich.gc.find_reachable_objects	38	0	0.0%	[]
dulwich.gc.garbage_collect	52	0	0.0%	[]
dulwich.gc.maybe_auto_gc	34	2	5.882%	['fuzz_object_store', 'fuzz_repo', 'fuzz_configfile', 'fuzz_bundle']
dulwich.patch.parse_patch_message	39	0	0.0%	[]
dulwich.protocol.ReceivableProtocol.read	31	0	0.0%	[]
dulwich.bundle._read_bundle	31	0	0.0%	['fuzz_bundle']

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
	[]	[]
dulwich.contrib.diffstat	[]	[]
signal	[]	[]
geventhttpclient	[]	[]
shlex	[]	[]
dulwich.greenthreads	[]	[]
dulwich.dumb	[]	[]
dulwich.sparse_patterns	[]	[]
...dulwich.fuzzing.fuzz-targets.fuzz_repo	['fuzz_repo']	[]
dulwich.repo	['fuzz_repo', 'fuzz_object_store']	[]
gzip	[]	[]
dulwich.contrib	[]	[]
cdifflib	[]	[]
dulwich.pack	['fuzz_bundle']	[]
dulwich.bundle	['fuzz_bundle']	[]
merge3	[]	[]
...dulwich.fuzzing.fuzz-targets.fuzz_object_store	['fuzz_object_store']	[]
dulwich.__main__	[]	[]
msvcrt	[]	[]
dulwich.patch	['fuzz_object_store']	[]
time	[]	[]
dulwich.submodule	[]	[]
tarfile	[]	[]
dulwich.refs	['fuzz_repo', 'fuzz_object_store']	[]
logging	[]	[]
shutil	[]	[]
io	[]	[]
dulwich.client	[]	[]
urllib	[]	[]
datetime	[]	[]
gc	[]	[]
functools	[]	[]
typing	[]	[]
subprocess	[]	[]
re	[]	[]
hashlib	[]	[]
dulwich.reflog	[]	[]
socket	[]	[]
paramiko	[]	[]
dulwich	[]	[]
platform	[]	[]
dulwich.index	[]	[]
gevent	[]	[]
requests	[]	[]
posixpath	[]	[]
dulwich.object_store	['fuzz_repo', 'fuzz_object_store']	[]
dulwich.contrib.release_robot	[]	[]
gpg	[]	[]
dataclasses	[]	[]
dulwich.commit_graph	[]	[]
os	[]	[]
copy	[]	[]
dulwich.contrib.swift	['fuzz_bundle']	[]
dulwich.walk	[]	[]
dulwich.graph	[]	[]
socketserver	[]	[]
itertools	[]	[]
difflib	[]	[]
dulwich.lfs	[]	[]
...dulwich.fuzzing.fuzz-targets.fuzz_bundle	['fuzz_bundle']	[]
dulwich.porcelain	[]	[]
wsgiref	[]	[]
test_utils	[]	[]
dulwich.hooks	['fuzz_repo']	[]
dulwich.cloud.gcs	[]	[]
	[]	[]
ctypes	[]	[]
dulwich.config	['fuzz_repo', 'fuzz_object_store', 'fuzz_configfile']	[]
dulwich.mailmap	[]	[]
...dulwich.fuzzing.fuzz-targets.fuzz_configfile	['fuzz_configfile']	[]
contextlib	[]	[]
dulwich.server	[]	[]
winreg	[]	[]
dulwich.web	[]	[]
dulwich.protocol	[]	[]
dulwich.stash	[]	[]
dulwich.contrib.paramiko_vendor	[]	[]
dulwich.objects	['fuzz_repo', 'fuzz_object_store']	[]
dulwich.log_utils	[]	[]
dulwich.cloud	[]	[]
argparse	[]	[]
pathlib	[]	[]
dulwich.cli	[]	[]
dulwich.ignore	[]	[]
pwd	[]	[]
dulwich.contrib.requests_vendor	[]	[]
dulwich.fastexport	[]	[]
dulwich.rebase	[]	[]
configparser	[]	[]
replace_me	[]	[]
dulwich.file	['fuzz_bundle']	[]
heapq	[]	[]
win32api	[]	[]
warnings	[]	[]
dulwich.line_ending	[]	[]
binascii	[]	[]
dulwich.filter_branch	[]	[]
dulwich.objectspec	[]	[]
struct	[]	[]
ipaddress	[]	[]
atheris	[]	[]
optparse	[]	[]
tempfile	[]	[]
collections	[]	[]
pdb	[]	[]
stat	[]	[]
dulwich.notes	[]	[]
mmap	[]	[]
dulwich.archive	[]	[]
urllib3	[]	[]
select	[]	[]
json	[]	[]
dulwich.merge	[]	[]
dulwich.errors	[]	[]
zlib	[]	[]
dulwich.lru_cache	[]	[]
dulwich.gc	[]	[]
fastimport	[]	[]
dulwich.diff_tree	[]	[]
glob	[]	[]
nturl2path	[]	[]
fnmatch	[]	[]
dulwich.annotate	[]	[]
dulwich.credentials	[]	[]
sys	[]	[]

Directories in report

Directory