High level conclusions

Fuzzers reach 7.880% of cyclomatic complexity.

Fuzzers reach 8.454% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

64 / 757

Cyclomatic complexity statically reachable by fuzzers

545 / 6916

Runtime code coverage of functions

64 / 757

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	Fuzzers runtime hit	Func lines hit %	I Count	BB Count	Cyclomatic complexity	Functions reached	Reached by functions	Accumulated cyclomatic complexity	Undiscovered complexity

Fuzzer: split_uri_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	23.8%
gold	[1:9]	10	47.6%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	6	28.5%
All colors	21	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
0	0	None	2	24	coap_log_impl	call site: 00000	/src/libcoap/src/coap_debug.c:1204

Runtime coverage analysis

Covered functions

14

Functions that are reachable but not covered

12

Reachable functions

26

Percentage of reachable functions covered

53.85%

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
tests/oss-fuzz/split_uri_target.c	1
src/coap_uri.c	2
src/coap_debug.c	1
src/coap_notls.c	2
src/coap_tcp.c	1
src/coap_ws.c	2

Fuzzer: pdu_parse_ws_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	52	19.7%
gold	[1:9]	11	4.18%
yellow	[10:29]	2	0.76%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	198	75.2%
All colors	263	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
0	35	2 : View List ['coap_log_impl', 'coap_get_log_level']	0	35	coap_pdu_resize	call site: 00019	/src/libcoap/src/coap_pdu.c:271
0	2	1 : View List ['coap_free_type']	0	2	coap_pdu_init	call site: 00006	/src/libcoap/src/coap_pdu.c:141
0	0	None	2	261	coap_split_uri_sub	call site: 00080	/src/libcoap/src/coap_uri.c:103
0	0	None	2	24	coap_log_impl	call site: 00117	/src/libcoap/src/coap_debug.c:1204
0	0	None	0	70	coap_pdu_parse_header	call site: 00022	/src/libcoap/src/coap_pdu.c:1008
0	0	None	0	39	coap_pdu_resize	call site: 00017	/src/libcoap/src/coap_pdu.c:262
0	0	None	0	35	coap_pdu_parse_header	call site: 00024	/src/libcoap/src/coap_pdu.c:1017
0	0	None	0	35	coap_pdu_parse_header	call site: 00025	/src/libcoap/src/coap_pdu.c:1022
0	0	None	0	35	coap_pdu_parse_opt	call site: 00000	/src/libcoap/src/coap_pdu.c:1277
0	0	None	0	0	coap_option_filter_op	call site: 00034	/src/libcoap/src/coap_option.c:479
0	0	None	0	0	coap_pdu_resize	call site: 00021	/src/libcoap/src/coap_pdu.c:280
0	0	None	0	0	coap_get_data_large	call site: 00171	/src/libcoap/src/coap_pdu.c:819

Runtime coverage analysis

Covered functions

63

Functions that are reachable but not covered

15

Reachable functions

78

Percentage of reachable functions covered

80.77%

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
tests/oss-fuzz/pdu_parse_ws_target.c	1
src/coap_pdu.c	10
src/coap_mem.c	3
src/coap_debug.c	12
src/coap_uri.c	6
src/coap_option.c	12
src/coap_encode.c	3
src/coap_str.c	2
src/coap_notls.c	2
src/coap_tcp.c	1
src/coap_ws.c	2
src/coap_time.c	3
src/coap_block.c	1

Fuzzer: pdu_parse_udp_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	52	19.7%
gold	[1:9]	13	4.94%
yellow	[10:29]	1	0.38%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	197	74.9%
All colors	263	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
0	35	2 : View List ['coap_log_impl', 'coap_get_log_level']	0	35	coap_pdu_resize	call site: 00019	/src/libcoap/src/coap_pdu.c:271
0	2	1 : View List ['coap_free_type']	0	2	coap_pdu_init	call site: 00006	/src/libcoap/src/coap_pdu.c:141
0	0	None	2	261	coap_split_uri_sub	call site: 00080	/src/libcoap/src/coap_uri.c:103
0	0	None	2	24	coap_log_impl	call site: 00117	/src/libcoap/src/coap_debug.c:1204
0	0	None	0	39	coap_pdu_resize	call site: 00017	/src/libcoap/src/coap_pdu.c:262
0	0	None	0	35	coap_pdu_parse_opt	call site: 00000	/src/libcoap/src/coap_pdu.c:1277
0	0	None	0	0	coap_option_filter_op	call site: 00034	/src/libcoap/src/coap_option.c:479
0	0	None	0	0	coap_pdu_resize	call site: 00021	/src/libcoap/src/coap_pdu.c:280
0	0	None	0	0	coap_get_data_large	call site: 00171	/src/libcoap/src/coap_pdu.c:819
0	0	None	0	0	coap_pdu_parse_header_size	call site: 00015	/src/libcoap/src/coap_pdu.c:925

Runtime coverage analysis

Covered functions

63

Functions that are reachable but not covered

15

Reachable functions

78

Percentage of reachable functions covered

80.77%

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
tests/oss-fuzz/pdu_parse_udp_target.c	1
src/coap_pdu.c	10
src/coap_mem.c	3
src/coap_debug.c	12
src/coap_uri.c	6
src/coap_option.c	12
src/coap_encode.c	3
src/coap_str.c	2
src/coap_notls.c	2
src/coap_tcp.c	1
src/coap_ws.c	2
src/coap_time.c	3
src/coap_block.c	1

Fuzzer: pdu_parse_tcp_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	49	18.6%
gold	[1:9]	12	4.56%
yellow	[10:29]	1	0.38%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	201	76.4%
All colors	263	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
0	35	2 : View List ['coap_log_impl', 'coap_get_log_level']	0	35	coap_pdu_resize	call site: 00019	/src/libcoap/src/coap_pdu.c:271
0	2	1 : View List ['coap_free_type']	0	2	coap_pdu_init	call site: 00006	/src/libcoap/src/coap_pdu.c:141
0	0	None	2	261	coap_split_uri_sub	call site: 00080	/src/libcoap/src/coap_uri.c:103
0	0	None	2	24	coap_log_impl	call site: 00117	/src/libcoap/src/coap_debug.c:1204
0	0	None	0	70	coap_pdu_parse_header	call site: 00022	/src/libcoap/src/coap_pdu.c:1008
0	0	None	0	39	coap_pdu_resize	call site: 00017	/src/libcoap/src/coap_pdu.c:262
0	0	None	0	35	coap_pdu_parse_opt	call site: 00000	/src/libcoap/src/coap_pdu.c:1277
0	0	None	0	0	coap_option_filter_op	call site: 00034	/src/libcoap/src/coap_option.c:479
0	0	None	0	0	coap_pdu_resize	call site: 00021	/src/libcoap/src/coap_pdu.c:280
0	0	None	0	0	coap_get_data_large	call site: 00171	/src/libcoap/src/coap_pdu.c:819
0	0	None	0	0	coap_pdu_encode_header	call site: 00251	/src/libcoap/src/coap_pdu.c:1449

Runtime coverage analysis

Covered functions

63

Functions that are reachable but not covered

15

Reachable functions

78

Percentage of reachable functions covered

80.77%

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
tests/oss-fuzz/pdu_parse_tcp_target.c	1
src/coap_pdu.c	10
src/coap_mem.c	3
src/coap_debug.c	12
src/coap_uri.c	6
src/coap_option.c	12
src/coap_encode.c	3
src/coap_str.c	2
src/coap_notls.c	2
src/coap_tcp.c	1
src/coap_ws.c	2
src/coap_time.c	3
src/coap_block.c	1

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
coap_new_context	/src/libcoap/src/coap_net.c	1	['struct.coap_address_t *']	48	0	255	53	17	444	0	4637	4068
coap_ws_read	/src/libcoap/src/coap_ws.c	3	['struct.coap_session_t.50 *', 'char *', 'size_t']	30	0	733	118	47	420	2	4569	301
coap_persist_startup	/src/libcoap/src/coap_threadsafe.c	5	['struct.coap_context_t *', 'char *', 'char *', 'char *', 'int']	54	0	33	6	3	423	0	4538	266
coap_new_client_session_oscore_psk	/src/libcoap/src/coap_threadsafe.c	6	['struct.coap_context_t *', 'struct.coap_address_t *', 'struct.coap_address_t *', 'int', 'struct.coap_dtls_cpsk_t *', 'struct.coap_oscore_conf_t *']	48	0	34	6	3	418	0	4501	227
coap_send	/src/libcoap/src/coap_threadsafe.c	2	['struct.coap_session_t *', 'struct.coap_pdu_t *']	51	0	34	6	3	400	0	4441	173
coap_resolve_address_info	/src/libcoap/src/coap_address.c	8	['struct.coap_str_const_t *', 'short', 'short', 'short', 'short', 'int', 'int', 'int']	4	0	365	71	26	36	0	151	89
coap_new_oscore_conf	/src/libcoap/src/coap_oscore.c	5	['size_t', 'char *', 'func_type *', 'char *', 'size_t']	8	0	45	8	4	37	0	157	79
coap_add_resource	/src/libcoap/src/coap_threadsafe.c	2	['struct.coap_context_t *', 'struct.coap_resource_t *']	50	0	28	6	3	402	0	4347	52
coap_netif_dgrm_write	/src/libcoap/src/coap_netif.c	3	['struct.coap_session_t *', 'char *', 'size_t']	6	0	105	20	8	42	0	170	47
coap_join_mcast_group_intf	/src/libcoap/src/coap_threadsafe.c	3	['struct.coap_context_t *', 'char *', 'char *']	6	0	31	6	3	43	0	144	40

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

Functions statically reachable by fuzzers

480 / 757

Cyclomatic complexity statically reachable by fuzzers

5734 / 6916

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	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.

tests/oss-fuzz/split_uri_target.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=['coap_split_uri_sub', 'coap_ws_is_supported']

tests/oss-fuzz/pdu_parse_ws_target.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=['coap_log_impl', 'coap_pdu_encode_header', 'coap_pdu_clear', 'coap_pdu_init', 'coap_pdu_parse', 'coap_option_iterator_init', 'coap_get_query', 'coap_new_string']

tests/oss-fuzz/pdu_parse_udp_target.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=['coap_pdu_encode_header', 'coap_log_impl', 'coap_pdu_clear', 'coap_pdu_init', 'coap_pdu_parse', 'coap_pdu_parse_header', 'coap_option_iterator_init', 'coap_get_query', 'coap_new_string']

tests/oss-fuzz/pdu_parse_tcp_target.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=['coap_log_impl', 'coap_pdu_clear', 'coap_pdu_init', 'coap_pdu_parse', 'coap_pdu_parse_header', 'coap_option_iterator_init', 'coap_get_query', 'coap_new_string']

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/libcoap/src/coap_subscribe.c	[]	[]
/src/libcoap/src/coap_hashkey.c	[]	[]
/src/libcoap/tests/oss-fuzz/pdu_parse_udp_target.c	['pdu_parse_udp_fuzzer']	[]
/src/libcoap/src/coap_notls.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/usr/include/x86_64-linux-gnu/bits/byteswap.h	[]	[]
/usr/include/x86_64-linux-gnu/bits/socket.h	[]	[]
/src/libcoap/src/coap_str.c	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/tests/oss-fuzz/split_uri_target.c	['split_uri_fuzzer']	[]
/src/libcoap/src/oscore/oscore_context.c	[]	[]
/src/libcoap/src/coap_async.c	[]	[]
/src/libcoap/src/coap_encode.c	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/src/coap_block.c	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/tests/oss-fuzz/pdu_parse_tcp_target.c	['pdu_parse_tcp_fuzzer']	[]
/src/libcoap/src/coap_uri.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/src/coap_netif.c	[]	[]
/src/libcoap/src/coap_prng.c	[]	[]
/src/libcoap/tests/oss-fuzz/pdu_parse_ws_target.c	['pdu_parse_ws_fuzzer']	[]
/src/libcoap/src/coap_threadsafe.c	[]	[]
/usr/include/stdlib.h	[]	[]
/src/libcoap/./include/coap3/coap_uri.h	[]	[]
/src/libcoap/src/oscore/oscore_cbor.c	[]	[]
/src/libcoap/src/oscore/oscore_crypto.c	[]	[]
/src/libcoap/src/coap_address.c	[]	[]
/src/libcoap/src/coap_debug.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/src/coap_tcp.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/src/coap_sha1.c	[]	[]
/src/libcoap/src/coap_session.c	[]	[]
/src/libcoap/src/coap_dtls.c	[]	[]
/src/libcoap/src/coap_pdu.c	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/src/coap_mem.c	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/src/coap_cache.c	[]	[]
/src/libcoap/src/oscore/oscore.c	[]	[]
/src/libcoap/src/coap_option.c	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/src/coap_net.c	[]	[]
/src/libcoap/src/oscore/oscore_cose.c	[]	[]
/src/libcoap/src/coap_time.c	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/src/coap_io.c	[]	[]
/src/libcoap/./include/coap3/coap_address.h	[]	[]
/src/libcoap/src/coap_ws.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_udp_fuzzer', 'pdu_parse_tcp_fuzzer']
/src/libcoap/src/coap_oscore.c	[]	[]
/src/libcoap/src/coap_resource.c	[]	[]

Directories in report

Directory
/usr/include/
/src/libcoap/./include/coap3/
/usr/include/x86_64-linux-gnu/bits/
/src/libcoap/src/oscore/
/src/libcoap/src/
/src/libcoap/tests/oss-fuzz/