Fuzz introspector
For issues and ideas: https://github.com/ossf/fuzz-introspector/issues
Project coverage
Per-fuzzer coverage

Table of contents

Project overview: gpsd
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: FuzzJson
Call tree
Fuzz blockers
Runtime coverage analysis
Files reached
Fuzzer: FuzzPacket
Call tree
Fuzz blockers
Runtime coverage analysis
Files reached
Analyses and suggestions
Optimal target analysis
Remaining optimal interesting functions
All functions overview
Fuzz engine guidance
/src/gpsd/fuzzer/FuzzJson.c
Dictionary
Fuzzer function priority
/src/gpsd/fuzzer/FuzzPacket.c
Dictionary
Fuzzer function priority
Runtime coverage analysis
Complex functions with low coverage
Files and Directories in report
Files in report
Directories in report
Metadata section
Sink analyser for CWEs
Report generation date: 2024-02-25

Project overview: gpsd

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
10.0%
68 / 677
Cyclomatic complexity statically reachable by fuzzers
16.0%
1173 / 7197
Runtime code coverage of functions
8.0%
56 / 677

Fuzzers overview

Fuzzer Fuzzer filename Functions Reached Functions unreached Fuzzer depth Files reached Basic blocks reached Cyclomatic complexity Details
FuzzJson /src/gpsd/fuzzer/FuzzJson.c 56 39 8 12 1284 564 FuzzJson.c
FuzzPacket /src/gpsd/fuzzer/FuzzPacket.c 57 721 8 10 1719 704 FuzzPacket.c

Project functions overview

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 details

Fuzzer: FuzzJson

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

Full calltree

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 23 7.25%
gold [1:9] 97 30.5%
yellow [10:29] 28 8.83%
greenyellow [30:49] 11 3.47%
lawngreen 50+ 158 49.8%
All colors 317 100

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 18 529 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:758
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 529 json_read_array call site: 00037 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779

Runtime coverage analysis

Covered functions
32
Functions that are reachable but not covered
24
Reachable functions
56
Percentage of reachable functions covered
57.14%
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/gpsd/fuzzer/FuzzJson.c 1
libgps/libgps_json.c 13
libgps/../include/strfuncs.h 2
libgps/json.c 5
libgps/os_compat.c 1
/usr/include/stdlib.h 3
libgps/gpsutils.c 3
libgps/shared_json.c 2
libgps/rtcm2_json.c 1
libgps/rtcm3_json.c 1
libgps/ais_json.c 2
libgps/hex.c 2

Fuzzer: FuzzPacket

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

Full calltree

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 104 32.3%
gold [1:9] 7 2.18%
yellow [10:29] 10 3.11%
greenyellow [30:49] 11 3.42%
lawngreen 50+ 189 58.8%
All colors 321 100

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
6 6 1 :

['gps_hexdump']

78 263 packet_parse call site: 00230 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:2495
0 658 2 :

['packet_discard', 'packet_parse']

108 766 packet_get1 call site: 00313 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:3417
0 0 None 312 970 packet_get1 call site: 00262 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:3378
0 0 None 256 914 packet_get1 call site: 00306 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:3389
0 0 None 72 72 isgps_decode call site: 00031 /src/gpsd/gpsd-3.25.1~dev/gpsd/isgps.c:262
0 0 None 36 207 packet_parse call site: 00210 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:2325
0 0 None 36 36 isgps_decode call site: 00033 /src/gpsd/gpsd-3.25.1~dev/gpsd/isgps.c:291
0 0 None 36 36 packet_accept call site: 00218 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:2051
0 0 None 36 36 packet_discard call site: 00222 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:2078
0 0 None 36 36 packet_unstash call site: 00255 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:2123
0 0 None 0 0 nextstate call site: 00090 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:985
0 0 None 0 0 nextstate call site: 00092 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:1001

Runtime coverage analysis

Covered functions
27
Functions that are reachable but not covered
30
Reachable functions
57
Percentage of reachable functions covered
47.37%
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/gpsd/fuzzer/FuzzPacket.c 1
gpsd/packet.c 16
gpsd/isgps.c 3
drivers/driver_rtcm2.c 2
gpsd/libgpsd_core.c 4
libgps/hex.c 2
gpsd/../include/strfuncs.h 1
/usr/include/ctype.h 1
drivers/driver_greis_checksum.c 2
gpsd/crc24q.c 2

Analyses and suggestions

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
gpsd_multipoll /src/gpsd/gpsd-3.25.1~dev/gpsd/libgpsd_core.c 4 ['bool', 'struct.gps_device_t.86 *', 'func_type *', 'float'] 10 0 459 86 36 183 0 1866 1113
parse_input /src/gpsd/gpsd-3.25.1~dev/drivers/driver_ubx.c 1 ['struct.gps_device_t *'] 8 0 31 6 3 122 0 1076 914
tsip_parse_input /src/gpsd/gpsd-3.25.1~dev/drivers/driver_tsip.c 1 ['struct.gps_device_t.593 *'] 7 0 4494 617 195 48 0 498 393
sirfbin_parse_input /src/gpsd/gpsd-3.25.1~dev/drivers/driver_sirf.c 1 ['struct.gps_device_t *'] 9 0 39 8 4 83 0 765 342
aivdm_analyze /src/gpsd/gpsd-3.25.1~dev/drivers/drivers.c 1 ['struct.gps_device_t.420 *'] 6 0 50 10 5 45 0 406 235
skybin_parse_input /src/gpsd/gpsd-3.25.1~dev/drivers/driver_skytraq.c 1 ['struct.gps_device_t.515 *'] 7 0 300 60 5 75 0 447 216
rtcm104v3_analyze /src/gpsd/gpsd-3.25.1~dev/drivers/drivers.c 1 ['struct.gps_device_t.420 *'] 6 0 50 6 3 22 0 252 194
gps_mainloop /src/gpsd/gpsd-3.25.1~dev/libgps/libgps_core.c 3 ['struct.gps_data_t *', 'int', 'func_type *'] 10 0 56 9 4 77 0 700 110
navcom_parse_input /src/gpsd/gpsd-3.25.1~dev/drivers/driver_navcom.c 1 ['struct.gps_device_t *'] 7 0 39 8 4 48 0 275 103
processRMC /src/gpsd/gpsd-3.25.1~dev/drivers/driver_nmea0183.c 3 ['int', 'char **', 'struct.gps_device_t *'] 6 0 389 70 25 31 0 186 97

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

Functions statically reachable by fuzzers
51.0%
348 / 677
Cyclomatic complexity statically reachable by fuzzers
67.0%
4790 / 7197

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

Fuzz engine guidance

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/gpsd/fuzzer/FuzzJson.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=['json_internal_read_object', 'strlcpy', 'json_read_array', 'json_read_object']

/src/gpsd/fuzzer/FuzzPacket.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=['packet_get', 'isgps_decode', 'nextstate', 'packet_get1']

Runtime coverage analysis

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
json_read_array 205 92 44.87% ['FuzzJson']
packet_get1 58 28 48.27% ['FuzzPacket']

Files and Directories in report

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/gpsd/gpsd-3.25.1~dev/drivers/driver_rtcm2.c ['FuzzPacket'] ['FuzzPacket']
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_ubx.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/rtcm3_json.c ['FuzzJson'] ['FuzzJson']
/src/gpsd/gpsd-3.25.1~dev/gpsd/geoid.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/../include/strfuncs.h ['FuzzPacket'] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/bsd_base64.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/libgps_json.c ['FuzzJson'] ['FuzzJson']
/src/gpsd/gpsd-3.25.1~dev/gpsd/isgps.c ['FuzzPacket'] ['FuzzPacket']
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_greis.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/../include/timespec.h [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/../include/compiler.h [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/netlib.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/timebase.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c ['FuzzPacket'] ['FuzzPacket']
/src/gpsd/gpsd-3.25.1~dev/libgps/libgps_shm.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/timespec_str.c [] []
/src/gpsd/fuzzer/FuzzPacket.c ['FuzzPacket'] ['FuzzPacket']
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_nmea2000.c [] []
/src/gpsd/fuzzer/FuzzJson.c ['FuzzJson'] ['FuzzJson']
/src/gpsd/gpsd-3.25.1~dev/gpsd/matrix.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/rtcm2_json.c ['FuzzJson'] ['FuzzJson']
/src/gpsd/gpsd-3.25.1~dev/libgps/libgps_core.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/subframe.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/net_ntrip.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_italk.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_rtcm3.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/libgps_sock.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/ppsthread.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/gps_maskdump.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_garmin.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/net_dgpsip.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_evermore.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_sirf.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_greis_checksum.c ['FuzzPacket'] ['FuzzPacket']
/src/gpsd/gpsd-3.25.1~dev/libgps/hex.c ['FuzzJson', 'FuzzPacket'] ['FuzzJson']
/usr/include/x86_64-linux-gnu/sys/stat.h [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/pseudoais.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_navcom.c [] []
/usr/include/stdlib.h ['FuzzJson'] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/net_gnss_dispatch.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_tsip.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/pseudonmea.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/bits.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/json.c ['FuzzJson'] ['FuzzJson']
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_nmea0183.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_superstar2.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/os_compat.c ['FuzzJson'] ['FuzzJson']
/usr/include/ctype.h ['FuzzPacket'] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_ais.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/shared_json.c ['FuzzJson'] ['FuzzJson']
/src/gpsd/gpsd-3.25.1~dev/gpsd/libgpsd_core.c ['FuzzPacket'] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_geostar.c [] []
/usr/include/x86_64-linux-gnu/sys/sysmacros.h [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/gpsutils.c ['FuzzJson'] ['FuzzJson']
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_garmin_txt.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/serial.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_zodiac.c [] []
/src/gpsd/gpsd-3.25.1~dev/libgps/ais_json.c ['FuzzJson'] ['FuzzJson']
/src/gpsd/gpsd-3.25.1~dev/libgps/../include/strfuncs.h ['FuzzJson'] []
/src/gpsd/gpsd-3.25.1~dev/drivers/drivers.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_skytraq.c [] []
/src/gpsd/gpsd-3.25.1~dev/drivers/driver_oncore.c [] []
/src/gpsd/gpsd-3.25.1~dev/gpsd/crc24q.c ['FuzzPacket'] ['FuzzPacket']

Directories in report

Directory
/src/gpsd/gpsd-3.25.1~dev/libgps/../include/
/src/gpsd/gpsd-3.25.1~dev/gpsd/
/usr/include/
/src/gpsd/gpsd-3.25.1~dev/libgps/
/src/gpsd/gpsd-3.25.1~dev/drivers/
/src/gpsd/fuzzer/
/usr/include/x86_64-linux-gnu/sys/
/src/gpsd/gpsd-3.25.1~dev/gpsd/../include/

Metadata section

This sections shows the raw data that is used to produce this report. This is mainly used for further processing and developer debugging.

Fuzzer Calltree file Program data file Coverage file
FuzzJson fuzzerLogFile-0-eiSNBoywfK.data fuzzerLogFile-0-eiSNBoywfK.data.yaml FuzzJson.covreport
FuzzPacket fuzzerLogFile-0-VfFBM7Mnvo.data fuzzerLogFile-0-VfFBM7Mnvo.data.yaml FuzzPacket.covreport