Fuzz introspector
For issues and ideas: https://github.com/ossf/fuzz-introspector/issues

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

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 22 6.96%
gold [1:9] 94 29.7%
yellow [10:29] 29 9.17%
greenyellow [30:49] 11 3.48%
lawngreen 50+ 160 50.6%
All colors 316 100

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 18 501 json_read_array call site: 00033 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:758
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /src/gpsd/gpsd-3.25.1~dev/libgps/json.c:779
0 0 None 18 501 json_read_array call site: 00035 /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
/usr/include/stdlib.h 3
libgps/gpsutils.c 3
libgps/os_compat.c 1
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

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 80 23.8%
gold [1:9] 0 0.0%
yellow [10:29] 0 0.0%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 256 76.1%
All colors 336 100

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: 00245 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:2676
0 57 1 :

['packet_discard']

108 165 packet_get1 call site: 00330 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:3619
0 0 None 312 994 packet_get1 call site: 00277 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:3567
0 0 None 256 938 packet_get1 call site: 00321 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:3578
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 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: 00233 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:2161
0 0 None 36 36 packet_discard call site: 00237 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:2188
0 0 None 36 36 packet_unstash call site: 00270 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:2233
0 0 None 0 0 nextstate call site: 00090 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:981
0 0 None 0 0 nextstate call site: 00092 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:995
0 0 None 0 0 nextstate call site: 00096 /src/gpsd/gpsd-3.25.1~dev/gpsd/packet.c:1023

Runtime coverage analysis

Covered functions
28
Functions that are reachable but not covered
30
Reachable functions
58
Percentage of reachable functions covered
48.28%
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 17
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', 'N/A', 'N/A', 'float'] 10 0 439 86 36 184 0 1849 1072
ubx_parse /src/gpsd/gpsd-3.25.1~dev/drivers/driver_ubx.c 3 ['N/A', 'N/A', 'size_t'] 7 0 2127 377 110 114 0 1032 917
tsip_parse_input /src/gpsd/gpsd-3.25.1~dev/drivers/driver_tsip.c 1 ['N/A'] 8 0 785 160 51 101 0 641 525
sirfbin_parse_input /src/gpsd/gpsd-3.25.1~dev/drivers/driver_sirf.c 1 ['N/A'] 9 0 39 8 4 87 0 789 412
aivdm_analyze /src/gpsd/gpsd-3.25.1~dev/drivers/drivers.c 1 ['N/A'] 6 0 49 10 5 45 0 404 235
skybin_parse_input /src/gpsd/gpsd-3.25.1~dev/drivers/driver_skytraq.c 1 ['N/A'] 7 0 300 60 5 75 0 447 213
rtcm104v3_analyze /src/gpsd/gpsd-3.25.1~dev/drivers/drivers.c 1 ['N/A'] 6 0 47 6 3 22 0 252 194
gps_mainloop /src/gpsd/gpsd-3.25.1~dev/libgps/libgps_core.c 3 ['N/A', 'int', 'N/A'] 10 0 55 9 4 77 0 702 110
navcom_parse_input /src/gpsd/gpsd-3.25.1~dev/drivers/driver_navcom.c 1 ['N/A'] 7 0 39 8 4 48 0 275 103
processGSV /src/gpsd/gpsd-3.25.1~dev/drivers/driver_nmea0183.c 3 ['int', 'N/A', 'N/A'] 5 0 831 154 55 20 0 144 102

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

Functions statically reachable by fuzzers
52.0%
402 / 777
Cyclomatic complexity statically reachable by fuzzers
65.0%
4980 / 7615

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

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

Directories in report

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