High level conclusions

Fuzzers reach 95.05% of cyclomatic complexity.

Fuzzers reach 90.43% of all functions.

Fuzzers reach 84.56% code coverage.

Fuzzer magic_fuzzer is blocked:

The runtime code coverage of magic_fuzzer covers 0.677% 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

293 / 324

Cyclomatic complexity statically reachable by fuzzers

3093 / 3254

Runtime code coverage of functions

274 / 324

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: magic_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	1243	99.8%
gold	[1:9]	1	0.08%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	1	0.08%
All colors	1245	100

Fuzz blockers

The followings are the branches where fuzzer fails to bypass.

Unique non-covered Complexity	Unique Reachable Complexities	Unique Reachable Functions	All non-covered Complexity	All Reachable Complexity	Function Name	Function Callsite	Blocked Branch
792	792	2 : View List ['file_magwarn', 'apprentice_load']	1079	1087	apprentice_1	call site: 00000	/src/file/src/apprentice.c:501
188	188	1 : View List ['apprentice_list']	188	188	apprentice_1	call site: 00000	/src/file/src/apprentice.c:521
103	103	1 : View List ['apprentice_compile']	880	880	apprentice_1	call site: 00000	/src/file/src/apprentice.c:492
72	72	4 : View List ['close', 'file_error', '__errno_location', 'apprentice_unmap']	72	72	apprentice_map	call site: 00000	/src/file/src/apprentice.c:3384
57	57	1 : View List ['file_oomem']	72	72	apprentice_map	call site: 00000	/src/file/src/apprentice.c:3335
55	55	1 : View List ['file_error']	55	55	apprentice_1	call site: 00000	/src/file/src/apprentice.c:485
55	55	1 : View List ['file_error']	55	55	check_buffer	call site: 00000	/src/file/src/apprentice.c:3452
55	55	1 : View List ['file_error']	55	55	file_reset	call site: 00002	/src/file/src/funcs.c:518
44	44	1 : View List ['mlist_free_one']	44	44	mlist_free	call site: 00000	/src/file/src/apprentice.c:685
22	22	2 : View List ['get_default_magic', 'getenv']	22	22	magic_getpath	call site: 00000	/src/file/src/magic.c:256
21	21	1 : View List ['byteswap']	21	21	check_buffer	call site: 00000	/src/file/src/apprentice.c:3457
5	5	2 : View List ['magic_error', 'exit']	5	5	Environment::Environment(std::__1::basic_string ,std::__1::allocator >)	call site: 00000	/src/magic_fuzzer.cc:28

Runtime coverage analysis

Covered functions

19

Functions that are reachable but not covered

293

Reachable functions

295

Percentage of reachable functions covered

0.68%

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/magic_fuzzer.cc	1
/src/file/src/magic.c	1
/src/file/src/funcs.c	33
/src/file/src/buffer.c	3
/src/file/src/encoding.c	10
/src/file/src/compress.c	16
/src/file/src/is_tar.c	3
/src/file/src/is_json.c	11
/src/file/src/is_csv.c	3
/src/file/src/is_simh.c	4
/src/file/src/readcdf.c	9
/src/file/src/cdf.c	40
/usr/include/x86_64-linux-gnu/bits/byteswap.h	3
/src/file/src/cdf_time.c	5
/src/file/src/readelf.c	21
/src/file/src/strlcpy.c	1
/src/file/src/softmagic.c	29
/src/file/src/apprentice.c	10
/src/file/src/print.c	9
/src/file/src/der.c	6
/src/file/src/fmtcheck.c	4
/src/file/src/ascmagic.c	4

Fuzzer: magic_fuzzer_loaddb

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	149	28.5%
gold	[1:9]	1	0.19%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	371	71.2%
All colors	521	100

Fuzz blockers

The followings are the branches where fuzzer fails to bypass.

Unique non-covered Complexity	Unique Reachable Complexities	Unique Reachable Functions	All non-covered Complexity	All Reachable Complexity	Function Name	Function Callsite	Blocked Branch
188	188	1 : View List ['apprentice_list']	188	188	apprentice_1	call site: 00498	/src/file/src/apprentice.c:521
104	324	7 : View List ['fstat', '__errno_location', 'mprotect', 'check_buffer', 'maxoff_t', 'file_error', 'mmap']	108	341	apprentice_map	call site: 00457	/src/file/src/apprentice.c:3345
57	57	1 : View List ['file_oomem']	59	72	apprentice_map	call site: 00454	/src/file/src/apprentice.c:3335
57	57	1 : View List ['file_oomem']	57	57	parse	call site: 00136	/src/file/src/apprentice.c:2099
57	57	1 : View List ['file_oomem']	57	57	parse	call site: 00137	/src/file/src/apprentice.c:2114
57	57	1 : View List ['file_oomem']	57	57	addentry	call site: 00394	/src/file/src/apprentice.c:1315
57	57	1 : View List ['file_oomem']	57	57	coalesce_entries	call site: 00431	/src/file/src/apprentice.c:1503
57	57	1 : View List ['file_oomem']	57	57	file_check_mem	call site: 00122	/src/file/src/funcs.c:628
22	22	2 : View List ['get_default_magic', 'getenv']	22	22	magic_getpath	call site: 00057	/src/file/src/magic.c:256
4	4	1 : View List ['__errno_location']	4	59	load_1	call site: 00112	/src/file/src/apprentice.c:1345
4	4	2 : View List ['close', 'abort']	4	4	fuzzer_get_tmpfile(unsignedcharconst*,unsignedlong)	call site: 00000	/src/fuzzer_temp_file.h:47
2	465	5 : View List ['getvalue', 'file_mdump', 'strlcpy', 'check_format', '__ctype_b_loc']	2	495	parse	call site: 00201	/src/file/src/apprentice.c:2382

Runtime coverage analysis

Covered functions

97

Functions that are reachable but not covered

78

Reachable functions

174

Percentage of reachable functions covered

55.17%

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/magic_fuzzer_loaddb.cc	1
/src/fuzzer_temp_file.h	5
/src/file/src/magic.c	7
/src/file/src/apprentice.c	53
/src/file/src/funcs.c	19
/src/file/src/print.c	9
/src/file/src/strlcpy.c	1
/src/file/src/cdf_time.c	4
/src/file/src/encoding.c	1
/usr/include/x86_64-linux-gnu/bits/byteswap.h	3

Fuzzer: magic_fuzzer_fd

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	449	33.5%
gold	[1:9]	38	2.83%
yellow	[10:29]	56	4.18%
greenyellow	[30:49]	18	1.34%
lawngreen	50+	778	58.1%
All colors	1339	100

Fuzz blockers

The followings are the branches where fuzzer fails to bypass.

Unique non-covered Complexity	Unique Reachable Complexities	Unique Reachable Functions	All non-covered Complexity	All Reachable Complexity	Function Name	Function Callsite	Blocked Branch
3263	3428	11 : View List ['magic_file', 'bad_link', 'readlink', '__errno_location', 'stat', 'gnu_dev_major', 'handle_mime', 'lstat', 'file_error', 'gnu_dev_minor', 'strerror']	3263	3428	file_fsmagic	call site: 00051	/src/file/src/fsmagic.c:117
792	792	2 : View List ['file_magwarn', 'apprentice_load']	1079	1087	apprentice_1	call site: 00000	/src/file/src/apprentice.c:501
197	197	3 : View List ['cdf_app_to_mime', 'cdf_tole2', 'cdf_file_catalog_info']	197	197	cdf_check_summary_info	call site: 00388	/src/file/src/readcdf.c:405
188	188	1 : View List ['apprentice_list']	188	188	apprentice_1	call site: 00000	/src/file/src/apprentice.c:521
139	139	2 : View List ['file_mdump', 'mdebug']	141	2572	mget	call site: 00955	/src/file/src/softmagic.c:1846
109	109	1 : View List ['file_pipe2file']	111	3203	file_tryelf	call site: 00817	/src/file/src/readelf.c:1930
103	103	1 : View List ['apprentice_compile']	880	880	apprentice_1	call site: 00000	/src/file/src/apprentice.c:492
79	79	1 : View List ['file_magic_strength']	79	79	magiccheck	call site: 01059	/src/file/src/softmagic.c:2509
67	89	2 : View List ['unreadable_info', 'sread']	69	2683	file_or_fd	call site: 00051	/src/file/src/magic.c:496
57	57	1 : View List ['file_oomem']	72	72	apprentice_map	call site: 00000	/src/file/src/apprentice.c:3335
57	57	1 : View List ['file_oomem']	57	57	file_ascmagic_with_encoding	call site: 01257	/src/file/src/ascmagic.c:146
57	57	1 : View List ['file_oomem']	57	57	file_encoding	call site: 00133	/src/file/src/encoding.c:153

Runtime coverage analysis

Covered functions

224

Functions that are reachable but not covered

117

Reachable functions

327

Percentage of reachable functions covered

64.22%

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/magic_fuzzer_fd.cc	1
/src/fuzzer_temp_file.h	5
/src/file/src/magic.c	5
/src/file/src/funcs.c	33
/src/file/src/fsmagic.c	3
/src/file/src/compress.c	16
/src/file/src/buffer.c	3
/src/file/src/encoding.c	10
/src/file/src/is_tar.c	3
/src/file/src/is_json.c	11
/src/file/src/is_csv.c	3
/src/file/src/is_simh.c	4
/src/file/src/readcdf.c	9
/src/file/src/cdf.c	40
/usr/include/x86_64-linux-gnu/bits/byteswap.h	3
/src/file/src/cdf_time.c	5
/src/file/src/readelf.c	21
/src/file/src/strlcpy.c	1
/src/file/src/softmagic.c	29
/src/file/src/apprentice.c	10
/src/file/src/print.c	9
/src/file/src/der.c	6
/src/file/src/fmtcheck.c	4
/src/file/src/ascmagic.c	4

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

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

Functions statically reachable by fuzzers

293 / 324

Cyclomatic complexity statically reachable by fuzzers

3093 / 3254

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/magic_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=['file_reset']

/src/magic_fuzzer_loaddb.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=['apprentice_map', 'apprentice_load', 'file_apprentice', 'add_mlist', 'apprentice_magic_strength_1', 'set_test_type', 'mlist_free_one', 'fuzzer_get_tmpfile(unsigned char const*, unsigned long)', 'fuzzer_get_tmpfile(unsigned char const*, unsigned long)']

/src/magic_fuzzer_fd.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=['file_or_fd', 'mcopy', 'magiccheck', 'file_tryelf', 'cdf_file_property_info', 'file_fmtdatetime', 'uncompressbuf', 'cdf_read_dir', 'check_regex', 'file_fmttime']

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
check_buffer	57	29	50.87%	['magic_fuzzer', 'magic_fuzzer_fd', 'magic_fuzzer_loaddb']
apprentice_load	101	44	43.56%	['magic_fuzzer_loaddb']
sread	52	27	51.92%	['magic_fuzzer', 'magic_fuzzer_fd']
get_next_format_from_precision	81	40	49.38%	['magic_fuzzer', 'magic_fuzzer_fd']
file_fsmagic	183	11	6.010%	['magic_fuzzer_fd']
file_or_fd	82	42	51.21%	['magic_fuzzer_fd']
cdf_check_summary_info	38	12	31.57%	['magic_fuzzer', 'magic_fuzzer_fd']
cvt_flip	56	22	39.28%	['magic_fuzzer', 'magic_fuzzer_fd']
handle_annotation	36	6	16.66%	['magic_fuzzer', 'magic_fuzzer_fd']

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/file/src/compress.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/usr/local/bin/../include/c++/v1/stdexcept	[]	[]
/src/file/src/readelf.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/file/src/cdf.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/magic_fuzzer_loaddb.cc	['magic_fuzzer_loaddb']	['magic_fuzzer_loaddb']
/src/file/src/ascmagic.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/usr/include/x86_64-linux-gnu/bits/byteswap.h	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']	[]
/src/magic_fuzzer_fd.cc	['magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/file/src/magic.c	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']
/src/file/src/apprentice.c	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']
/src/file/src/strlcpy.c	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']	['magic_fuzzer_loaddb', 'magic_fuzzer_fd']
/src/file/src/readcdf.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/file/src/fmtcheck.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/file/src/buffer.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/magic_fuzzer.cc	['magic_fuzzer']	['magic_fuzzer']
/src/file/src/der.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/file/src/is_simh.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/fuzzer_temp_file.h	['magic_fuzzer_loaddb', 'magic_fuzzer_fd']	['magic_fuzzer_loaddb', 'magic_fuzzer_fd']
/src/file/src/print.c	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']	['magic_fuzzer_loaddb', 'magic_fuzzer_fd']
/src/file/src/is_json.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/file/src/funcs.c	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']
/src/file/src/softmagic.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/file/src/is_csv.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/file/src/fsmagic.c	['magic_fuzzer_fd']	['magic_fuzzer_fd']
/src/file/src/encoding.c	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']	['magic_fuzzer_loaddb', 'magic_fuzzer_fd']
/src/file/src/cdf_time.c	['magic_fuzzer', 'magic_fuzzer_loaddb', 'magic_fuzzer_fd']	['magic_fuzzer_loaddb', 'magic_fuzzer_fd']
/src/file/src/is_tar.c	['magic_fuzzer', 'magic_fuzzer_fd']	['magic_fuzzer_fd']

Directories in report

Directory
/src/
/src/file/src/
/usr/local/bin/../include/c++/v1/
/usr/include/x86_64-linux-gnu/bits/