High level conclusions

Fuzzers reach 98.27% of cyclomatic complexity.

Fuzzers reach 96.55% of all functions.

Fuzzers reach 91.37% code coverage.

Reachability and coverage overview

Functions statically reachable by fuzzers

56 / 58

Cyclomatic complexity statically reachable by fuzzers

399 / 406

Runtime code coverage of functions

53 / 58

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: cgif_file_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	2	2.53%
gold	[1:9]	0	0.0%
yellow	[10:29]	3	3.79%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	74	93.6%
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
2	10	cgif_newgif	call site: 00010	fclose

Runtime coverage analysis

Covered functions

33

Functions that are reachable but not covered

4

Reachable functions

40

Percentage of reachable functions covered

90.0%

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
fuzz/cgif_file_fuzzer.c	5
build/../src/cgif.c	12
build/../src/cgif_raw.c	16

Fuzzer: cgif_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	5	6.49%
gold	[1:9]	0	0.0%
yellow	[10:29]	1	1.29%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	71	92.2%
All colors	77	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	9	processInput(ByteStream*)	call site: 00009	fopen64
1	21	initAppExtBlock	call site: 00021	fclose
1	73	cgif_close	call site: 00073	fclose

Runtime coverage analysis

Covered functions

34

Functions that are reachable but not covered

3

Reachable functions

39

Percentage of reachable functions covered

92.31%

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
fuzz/cgif_fuzzer.c	5
build/../src/cgif.c	12
build/../src/cgif_raw.c	16

Fuzzer: cgif_rgb_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	21	18.2%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	1	0.86%
lawngreen	50+	93	80.8%
All colors	115	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
11	73	cgif_addframe	call site: 00073	doWidthHeightOptim
3	9	cgif_rgb_newgif	call site: 00009	fopen64
3	16	initMainHeader	call site: 00016	writeDummyBytes
2	21	initAppExtBlock	call site: 00021	freeCGIF
1	69	cgif_rgb_addframe	call site: 00069	memcmp
1	111	cgif_close	call site: 00111	fclose

Runtime coverage analysis

Covered functions

54

Functions that are reachable but not covered

7

Reachable functions

63

Percentage of reachable functions covered

88.89%

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
fuzz/cgif_rgb_fuzzer.c	5
build/../src/cgif_rgb.c	23
build/../src/cgif.c	12
build/../src/cgif_raw.c	16

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

56 / 58

Cyclomatic complexity statically reachable by fuzzers

399 / 406

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.

fuzz/cgif_file_fuzzer.c

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=['cgif_newgif']

fuzz/cgif_fuzzer.c

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=['processInput(ByteStream*)', 'initAppExtBlock', 'cgif_close']

fuzz/cgif_rgb_fuzzer.c

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=['cgif_addframe', 'cgif_rgb_newgif', 'initMainHeader', 'initAppExtBlock', 'cgif_rgb_addframe', 'cgif_close']

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

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/cgif/build/../src/cgif_raw.c	['cgif_file_fuzzer', 'cgif_fuzzer', 'cgif_rgb_fuzzer']	[]
/src/cgif/build/../src/cgif_rgb.c	['cgif_rgb_fuzzer']	[]
/src/cgif/fuzz/cgif_file_fuzzer.c	['cgif_file_fuzzer']	['cgif_file_fuzzer']
/src/cgif/fuzz/cgif_fuzzer.c	['cgif_fuzzer']	['cgif_fuzzer']
/src/cgif/fuzz/cgif_rgb_fuzzer.c	['cgif_rgb_fuzzer']	['cgif_rgb_fuzzer']
/src/cgif/build/../src/cgif.c	['cgif_file_fuzzer', 'cgif_fuzzer', 'cgif_rgb_fuzzer']	[]

Directories in report

Directory
/src/cgif/build/../src/
/src/cgif/fuzz/