High level conclusions

Fuzzers reach 92.95% of cyclomatic complexity.

Fuzzers reach 87.45% of all functions.

Fuzzer fuzz_translate_generic is blocked:

The runtime code coverage of fuzz_translate_generic 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_backtranslate is blocked:

The runtime code coverage of fuzz_backtranslate 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

223 / 255

Cyclomatic complexity statically reachable by fuzzers

2733 / 2940

Runtime code coverage of functions

49 / 255

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_backtranslate

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	868	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	868	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
867	0	EP	call site: 00000	lou_backTranslateString

Runtime coverage analysis

Covered functions

0

Functions that are reachable but not covered

181

Reachable functions

181

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
/src/liblouis/tests/fuzzing/fuzz_backtranslate.c	2
/src/liblouis/liblouis/logging.c	3
/src/liblouis/liblouis/compileTranslationTable.c	96
/src/liblouis/tools/gnulib/free.c	1
/src/liblouis/liblouis/utils.c	7
/src/liblouis/liblouis/./internal.h	1
/src/liblouis/liblouis/pattern.c	15
/src/liblouis/liblouis/lou_backTranslateString.c	37
/src/liblouis/liblouis/commonTranslationFunctions.c	3

Fuzzer: table_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	578	84.1%
gold	[1:9]	98	14.2%
yellow	[10:29]	5	0.72%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	6	0.87%
All colors	687	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
33	33	3 : View List ['realloc', '_lou_outOfMemory', 'compileError']	33	33	allocateSpaceInDisplayTable	call site: 00157	/src/liblouis/liblouis/compileTranslationTable.c:468
33	33	3 : View List ['realloc', '_lou_outOfMemory', 'compileError']	33	33	allocateSpaceInTranslationTable	call site: 00046	/src/liblouis/liblouis/compileTranslationTable.c:435
25	45	5 : View List ['rpl_free', '_lou_findOpcodeName', '_lou_logMessage', 'printSource', 'strdup']	25	45	addForwardRuleWithSingleChar	call site: 00173	/src/liblouis/liblouis/compileTranslationTable.c:843
15	15	1 : View List ['compileError']	15	23	includeFile	call site: 00108	/src/liblouis/liblouis/compileTranslationTable.c:4944
15	15	1 : View List ['compileError']	15	15	getAChar	call site: 00087	/src/liblouis/liblouis/compileTranslationTable.c:307
15	15	1 : View List ['compileError']	15	15	parseDots	call site: 00139	/src/liblouis/liblouis/compileTranslationTable.c:1508
15	15	1 : View List ['compileError']	15	15	compileCharDef	call site: 00141	/src/liblouis/liblouis/compileTranslationTable.c:2657
6	6	1 : View List ['fgetc']	21	21	getAChar	call site: 00087	/src/liblouis/liblouis/compileTranslationTable.c:305
4	4	2 : View List ['addBackwardPassRule', 'addForwardPassRule']	45	181	addRule	call site: 00167	/src/liblouis/liblouis/compileTranslationTable.c:1046
0	40	1 : View List ['putDots']	0	40	addForwardRuleWithSingleChar	call site: 00170	/src/liblouis/liblouis/compileTranslationTable.c:824
0	12	1 : View List ['_lou_logMessage']	0	12	getTable	call site: 00011	/src/liblouis/liblouis/compileTranslationTable.c:5177
0	12	1 : View List ['_lou_logMessage']	0	12	compileFile	call site: 00119	/src/liblouis/liblouis/compileTranslationTable.c:4878

Runtime coverage analysis

Covered functions

50

Functions that are reachable but not covered

74

Reachable functions

121

Percentage of reachable functions covered

38.84%

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/liblouis/tests/fuzzing/table_fuzzer.cc	1
/src/liblouis/liblouis/compileTranslationTable.c	89
/src/liblouis/liblouis/logging.c	2
/src/liblouis/tools/gnulib/free.c	1
/src/liblouis/liblouis/utils.c	5
/src/liblouis/liblouis/./internal.h	1
/src/liblouis/liblouis/pattern.c	8

Fuzzer: fuzz_translate_generic

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	1074	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	1074	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
1073	0	EP	call site: 00000	lou_translateString

Runtime coverage analysis

Covered functions

0

Functions that are reachable but not covered

228

Reachable functions

228

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
/src/liblouis/tests/fuzzing/fuzz_translate_generic.c	2
/src/liblouis/liblouis/logging.c	4
/src/liblouis/liblouis/compileTranslationTable.c	96
/src/liblouis/tools/gnulib/free.c	1
/src/liblouis/liblouis/utils.c	8
/src/liblouis/liblouis/./internal.h	1
/src/liblouis/liblouis/pattern.c	15
/src/liblouis/liblouis/lou_translateString.c	74
/src/liblouis/liblouis/commonTranslationFunctions.c	3

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
_lou_defaultTableResolver	/src/liblouis/liblouis/compileTranslationTable.c	2	['N/A', 'N/A']	4	0	228	36	12	17	0	83	55

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

Functions statically reachable by fuzzers

226 / 255

Cyclomatic complexity statically reachable by fuzzers

2780 / 2940

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/liblouis/tests/fuzzing/fuzz_backtranslate.c

Dictionary

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

/src/liblouis/tests/fuzzing/table_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=['addBackwardRuleWithSingleCell', 'parseChars', 'addForwardRuleWithSingleChar', 'compileRule', 'getAChar', 'getRuleDotsPattern', 'compileFile', 'compileTable', 'rpl_free']

/src/liblouis/tests/fuzzing/fuzz_translate_generic.c

Dictionary

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

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
parseChars	125	30	24.0%	['table_fuzzer', 'fuzz_backtranslate', 'fuzz_translate_generic']
resolveSubtable	68	23	33.82%	['table_fuzzer']
compileTable	70	36	51.42%	['table_fuzzer', 'fuzz_backtranslate', 'fuzz_translate_generic']
compileRule	1306	31	2.373%	['table_fuzzer', 'fuzz_backtranslate', 'fuzz_translate_generic']
addForwardRuleWithSingleChar	45	19	42.22%	['table_fuzzer', 'fuzz_backtranslate', 'fuzz_translate_generic']

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/liblouis/liblouis/logging.c	['fuzz_backtranslate', 'table_fuzzer', 'fuzz_translate_generic']	['table_fuzzer']
/src/liblouis/liblouis/lou_translateString.c	['fuzz_translate_generic']	[]
/src/liblouis/tests/fuzzing/fuzz_translate_generic.c	['fuzz_translate_generic']	[]
/src/liblouis/liblouis/lou_backTranslateString.c	['fuzz_backtranslate']	[]
/src/liblouis/liblouis/./internal.h	['fuzz_backtranslate', 'table_fuzzer', 'fuzz_translate_generic']	[]
/src/liblouis/tests/fuzzing/table_fuzzer.cc	['table_fuzzer']	['table_fuzzer']
/src/liblouis/liblouis/utils.c	['fuzz_backtranslate', 'table_fuzzer', 'fuzz_translate_generic']	['table_fuzzer']
/src/liblouis/liblouis/compileTranslationTable.c	['fuzz_backtranslate', 'table_fuzzer', 'fuzz_translate_generic']	['table_fuzzer']
/src/liblouis/liblouis/pattern.c	['fuzz_backtranslate', 'table_fuzzer', 'fuzz_translate_generic']	[]
/src/liblouis/tools/gnulib/free.c	['fuzz_backtranslate', 'table_fuzzer', 'fuzz_translate_generic']	['table_fuzzer']
/src/liblouis/liblouis/commonTranslationFunctions.c	['fuzz_backtranslate', 'fuzz_translate_generic']	[]
/src/liblouis/tests/fuzzing/fuzz_backtranslate.c	['fuzz_backtranslate']	[]
/usr/local/bin/../include/c++/v1/stdexcept	[]	[]

Directories in report

Directory
/src/liblouis/liblouis/./
/src/liblouis/liblouis/
/usr/local/bin/../include/c++/v1/
/src/liblouis/tests/fuzzing/
/src/liblouis/tools/gnulib/