High level conclusions

Fuzzer fuzz_menu is blocked:

The runtime code coverage of fuzz_menu covers 2.259% 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_xml_parse is blocked:

The runtime code coverage of fuzz_xml_parse 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.

Fuzzer fuzz_desktop_entry is blocked:

The runtime code coverage of fuzz_desktop_entry covers 8.0% 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_icon is blocked:

The runtime code coverage of fuzz_icon covers 11.66% 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_mime is blocked:

The runtime code coverage of fuzz_mime 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

100 / 666

Cyclomatic complexity statically reachable by fuzzers

425 / 2451

Runtime code coverage of functions

28 / 666

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_mime

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	114	88.3%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	15	11.6%
All colors	129	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
107	5	...fuzz_mime.TestOneInput	call site: 00005	xdg.Mime.get_type_by_name
2	113	...fuzz_mime.TestOneInput	call site: 00113	xdg.Mime.update_cache
2	116	...fuzz_mime.TestOneInput	call site: 00116	xdg.Mime.update_cache
2	126	...fuzz_mime.TestOneInput	call site: 00126	.str
1	123	...fuzz_mime.TestOneInput	call site: 00123	xdg.Mime.MagicDB.__init__

Runtime coverage analysis

Covered functions

31

Functions that are reachable but not covered

72

Reachable functions

72

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
/	1
...fuzz_mime	14
xdg.Mime	63
xdg.BaseDirectory	2

Fuzzer: fuzz_icon

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	157	89.2%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	19	10.7%
All colors	176	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
141	23	...fuzz_icon.TestOneInput	call site: 00023	xdg.DesktopEntry.DesktopEntry.checkKey
7	168	...fuzz_icon.TestOneInput	call site: 00168	xdg.IconTheme.IconData.__init__
4	17	xdg.IconTheme.IconTheme.parse	call site: 00017	xdg.IconTheme.IconData.parse
3	10	xdg.IconTheme.IconTheme.parse	call site: 00010	xdg.IconTheme.IconTheme.parse
1	3	...fuzz_icon.TestOneInput	call site: 00003	f.write
1	7	xdg.IniFile.IniFile.__init__	call site: 00007	xdg.IconTheme.IconTheme.parse

Runtime coverage analysis

Covered functions

32

Functions that are reachable but not covered

53

Reachable functions

60

Percentage of reachable functions covered

11.67%

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
/	1
...fuzz_icon	10
xdg.IconTheme	15
xdg.IniFile	35
xdg.DesktopEntry	14

Fuzzer: fuzz_desktop_entry

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	114	85.7%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	19	14.2%
All colors	133	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
82	49	...fuzz_desktop_entry.TestOneInput	call site: 00049	xdg.IniFile.IniFile.checkValue
26	19	xdg.DesktopEntry.DesktopEntry.parse	call site: 00019	xdg.DesktopEntry.DesktopEntry.new
3	10	xdg.DesktopEntry.DesktopEntry.parse	call site: 00010	xdg.DesktopEntry.DesktopEntry.parse
2	16	xdg.IconTheme.IconTheme.parse	call site: 00016	os.path.dirname
1	7	xdg.DesktopEntry.DesktopEntry.__init__	call site: 00007	xdg.DesktopEntry.DesktopEntry.parse

Runtime coverage analysis

Covered functions

32

Functions that are reachable but not covered

46

Reachable functions

50

Percentage of reachable functions covered

8.0%

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
/	1
...fuzz_desktop_entry	9
xdg.DesktopEntry	19
xdg.IconTheme	5
xdg.IniFile	23

Fuzzer: fuzz_xml_parse

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	75.0%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	1	25.0%
All colors	4	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
3	0	EP	call site: 00000	atheris.FuzzedDataProvider

Runtime coverage analysis

Covered functions

31

Functions that are reachable but not covered

4

Reachable functions

4

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.

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
...inspector.light.source_files.src.lxml.src.lxml.tests.fuzz_xml_parse	3

Fuzzer: fuzz_menu

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	332	95.9%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	14	4.04%
All colors	346	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
165	6	...fuzz_menu.TestOneInput	call site: 00006	xdg.Menu.parse
160	185	xdg.DesktopEntry.DesktopEntry.parse	call site: 00185	xdg.Menu.XMLMenuBuilder.parse_kde_legacy_dirs
3	177	xdg.IconTheme.IconTheme.parse	call site: 00177	xdg.IconTheme.IconTheme.parse
2	181	xdg.IconTheme.IconTheme.parse	call site: 00181	os.path.dirname
1	1	...fuzz_menu.TestOneInput	call site: 00001	et.XML
1	173	xdg.DesktopEntry.DesktopEntry.__init__	call site: 00173	xdg.DesktopEntry.DesktopEntry.parse

Runtime coverage analysis

Covered functions

32

Functions that are reachable but not covered

173

Reachable functions

177

Percentage of reachable functions covered

2.26%

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
/	1
...fuzz_menu	10
xdg.Menu	147
xdg.DesktopEntry	10
xdg.IconTheme	5
xdg.IniFile	14

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
lxml.html._diffcommand.main	lxml.html._diffcommand	1	['N/A']	6	0	5	5	5	115	1	379	352
lxml.html._difflib.HtmlDiff.make_table	lxml.html._difflib	7	['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A']	8	0	4	5	5	85	1	289	268
lxml.doctestcompare.LXMLOutputChecker.output_difference	lxml.doctestcompare	4	['N/A', 'N/A', 'N/A', 'N/A']	5	0	3	3	4	49	0	166	133
lxml.sax.ElementTreeProducer.saxify	lxml.sax	1	['N/A']	2	0	6	2	4	26	1	86	77
xdg.MenuEditor.MenuEditor.__addEntry	xdg.MenuEditor	5	['N/A', 'N/A', 'N/A', 'N/A', 'N/A']	3	0	8	6	5	24	7	83	74
lxml.ElementInclude._include	lxml.ElementInclude	5	['N/A', 'N/A', 'N/A', 'N/A', 'N/A']	2	0	2	15	9	22	2	82	73
xdg.IconTheme.getIconPath	xdg.IconTheme	4	['N/A', 'N/A', 'N/A', 'N/A']	10	0	1	11	7	44	1	160	67
lxml.html.HtmlMixin.rewrite_links	lxml.html	4	['N/A', 'N/A', 'N/A', 'N/A']	10	0	4	7	6	24	3	90	65
lxml.html.soupparser._parse	lxml.html.soupparser	4	['N/A', 'N/A', 'N/A', 'N/A']	3	0	0	6	5	23	3	78	63
lxml.html._MethodFunc.__call__	lxml.html	4	['N/A', 'N/A', 'N/A', 'N/A']	3	0	0	5	5	28	0	100	52

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

Functions statically reachable by fuzzers

226 / 666

Cyclomatic complexity statically reachable by fuzzers

940 / 2451

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/fuzz_mime.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=['...fuzz_mime.TestOneInput']

/src/fuzz_icon.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=['...fuzz_icon.TestOneInput', 'xdg.IconTheme.IconTheme.parse', 'xdg.IniFile.IniFile.__init__']

/src/fuzz_desktop_entry.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=['...fuzz_desktop_entry.TestOneInput', 'xdg.DesktopEntry.DesktopEntry.parse', 'xdg.IconTheme.IconTheme.parse', 'xdg.DesktopEntry.DesktopEntry.__init__']

/src/inspector/light/source_files/src/lxml/src/lxml/tests/fuzz_xml_parse.py

Dictionary

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

/src/fuzz_menu.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=['...fuzz_menu.TestOneInput', 'xdg.DesktopEntry.DesktopEntry.parse', 'xdg.IconTheme.IconTheme.parse', 'xdg.DesktopEntry.DesktopEntry.__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
xdg.Locale._expand_lang	32	0	0.0%	[]
xdg.DesktopEntry.DesktopEntry.checkKey	137	0	0.0%	['fuzz_icon', 'fuzz_desktop_entry']
xdg.IconTheme.IconTheme.checkKey	45	1	2.222%	['fuzz_desktop_entry', 'fuzz_icon', 'fuzz_xml_parse', 'fuzz_mime', 'fuzz_menu']
xdg.IconTheme.getIconPath	41	0	0.0%	[]
xdg.IniFile.IniFile.get	38	0	0.0%	['fuzz_menu', 'fuzz_icon', 'fuzz_desktop_entry']

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
	[]	[]
lxml.sax	[]	[]
lxml.html.clean	[]	[]
heapq	[]	[]
fcntl	[]	[]
doctest	[]	[]
xdg.Config	[]	[]
etree	[]	[]
xdg.Locale	[]	[]
...fuzz_icon	['fuzz_icon']	[]
difflib	[]	[]
xdg.Menu	['fuzz_menu']	[]
lxml.pyclasslookup	[]	[]
lxml.html.diff	[]	[]
lxml	[]	[]
lxml.html	[]	[]
time	[]	[]
lxml.includes.extlibs	[]	[]
lxml.html._setmixin	[]	[]
lxml.html.html5parser	[]	[]
ast	[]	[]
lxml.builder	[]	[]
lxml.html._html5builder	[]	[]
xdg.Exceptions	[]	[]
lxml._elementpath	[]	[]
webbrowser	[]	[]
lxml.includes.libxslt	[]	[]
...fuzz_menu	['fuzz_menu']	[]
os	[]	[]
...fuzz_desktop_entry	['fuzz_desktop_entry']	[]
urlparse	[]	[]
lxml.ElementInclude	[]	[]
lxml.html.ElementSoup	[]	[]
lxml.html.builder	[]	[]
stat	[]	[]
urllib2	[]	[]
io	[]	[]
lxml.html._diffcommand	[]	[]
xdg.Mime	['fuzz_mime']	[]
...fuzz_mime	['fuzz_mime']	[]
sys	[]	[]
functools	[]	[]
lxml.cssselect	[]	[]
xdg.util	[]	[]
xdg.IniFile	['fuzz_icon', 'fuzz_desktop_entry', 'fuzz_menu']	[]
...inspector.light.source_files.src.lxml.src.lxml.tests.fuzz_xml_parse	['fuzz_xml_parse']	[]
xdg.MenuEditor	[]	[]
lxml.includes	[]	[]
shutil	[]	[]
xdg.BaseDirectory	['fuzz_mime']	[]
xdg.RecentFiles	[]	[]
xdg.IconTheme	['fuzz_icon', 'fuzz_desktop_entry', 'fuzz_menu']	[]
collections	[]	[]
html5lib	[]	[]
subprocess	[]	[]
fnmatch	[]	[]
lxml.html.soupparser	[]	[]
lxml.html.defs	[]	[]
atheris	[]	[]
getpass	[]	[]
lxml.includes.libxml	[]	[]
lxml.html.formfill	[]	[]
lxml.isoschematron	[]	[]
optparse	[]	[]
tempfile	[]	[]
lxml.html._difflib	[]	[]
locale	[]	[]
xml	[]	[]
	[]	[]
lxml.doctestcompare	[]	[]
re	[]	[]
warnings	[]	[]
xdg	[]	[]
html	[]	[]
cssselect	[]	[]
lxml.usedoctest	[]	[]
lxml.includes.libexslt	[]	[]
xdg.DesktopEntry	['fuzz_icon', 'fuzz_desktop_entry', 'fuzz_menu']	[]
cgi	[]	[]
urllib	[]	[]
bs4	[]	[]
lxml.html.usedoctest	[]	[]
BeautifulSoup	[]	[]

Directories in report

Directory