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

Fuzzer details

Fuzzer: read_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 0 210 39.6%
gold [1:9] 5 0.94%
yellow [10:29] 1 0.18%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 314 59.2%
All colors 530 100

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
108 1511 4 :

['get_next_frame', 'decode_the_frame', 'INT123_decode_update', 'frame_buffercheck']

108 1511 mpg123_decode call site: 00114 /src/mpg123/src/libmpg123/libmpg123.c:1121
24 24 1 :

['INT123_make_conv16to8_table']

24 46 INT123_set_synth_functions call site: 00180 /src/mpg123/src/libmpg123/optimize.c:423
6 26 2 :

['INT123_fi_resize', 'fi_shrink']

6 28 INT123_fi_add call site: 00483 /src/mpg123/src/libmpg123/index.c:84
4 4 1 :

['INT123_do_equalizer']

14 14 INT123_synth_1to1_stereo_avx call site: 00000 /src/mpg123/src/libmpg123/synth.c:510
4 4 1 :

['fcntl']

6 22 default_init call site: 00000 /src/mpg123/src/libmpg123/readers.c:1022
4 4 1 :

['find_synth']

4 13 find_dectype call site: 00170 /src/mpg123/src/libmpg123/optimize.c:235
4 4 2 :

['close', 'abort']

4 4 fuzzer_get_tmpfile call site: 00013 /src/read_fuzzer.c:29
2 2 1 :

['strcasecmp']

2 2 INT123_dectype call site: 00077 /src/mpg123/src/libmpg123/optimize.c:927
0 303 3 :

['enc_chan_fit', 'INT123_frame_freq', 'rate2num']

0 317 INT123_frame_output_format call site: 00137 /src/mpg123/src/libmpg123/format.c:290
0 105 3 :

['imin', 'imax', 'cap_fit']

0 105 enc_chan_fit call site: 00126 /src/mpg123/src/libmpg123/format.c:194
0 54 2 :

['INT123_frame_exit', 'free']

0 54 mpg123_parnew call site: 00076 /src/mpg123/src/libmpg123/libmpg123.c:107
0 28 1 :

['INT123_frame_index_setup']

0 30 mpg123_param call site: 00092 /src/mpg123/src/libmpg123/libmpg123.c:170

Runtime coverage analysis

Covered functions
172
Functions that are reachable but not covered
73
Reachable functions
206
Percentage of reachable functions covered
64.56%
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/read_fuzzer.c 3
/src/mpg123/src/libmpg123/libmpg123.c 18
/src/mpg123/./src/libmpg123/sample.h 1
/src/mpg123/src/libmpg123/frame.c 28
/src/mpg123/./src/libmpg123/getcpuflags.h 1
/src/mpg123/src/libmpg123/optimize.c 7
/src/mpg123/src/libmpg123/icy.c 3
/src/mpg123/src/libmpg123/id3.c 23
/src/mpg123/src/libmpg123/format.c 17
/src/mpg123/src/libmpg123/readers.c 14
/src/mpg123/src/libmpg123/stringbuf.c 6
/src/mpg123/src/libmpg123/index.c 7
/src/mpg123/src/compat/compat_str.c 1
/src/mpg123/src/libmpg123/layer3.c 2
/src/mpg123/./src/libmpg123/dither_impl.h 3
/src/mpg123/src/compat/compat.c 1
/src/mpg123/src/libmpg123/parse.c 20
/src/mpg123/src/libmpg123/ntom.c 7
/src/mpg123/src/libmpg123/tabinit.c 1
/src/mpg123/src/libmpg123/layer2.c 1
/src/mpg123/./src/libmpg123/gapless.h 1
/src/mpg123/./src/libmpg123/getbits.h 1
/src/mpg123/src/libmpg123/layer1.c 4

Fuzzer: decode_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 0 179 34.9%
gold [1:9] 5 0.97%
yellow [10:29] 0 0.0%
greenyellow [30:49] 5 0.97%
lawngreen 50+ 323 63.0%
All colors 512 100

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
24 24 1 :

['INT123_make_conv16to8_table']

24 46 INT123_set_synth_functions call site: 00175 /src/mpg123/src/libmpg123/optimize.c:423
4 4 1 :

['INT123_do_equalizer']

14 14 INT123_synth_1to1_stereo_avx call site: 00000 /src/mpg123/src/libmpg123/synth.c:510
4 4 1 :

['find_synth']

4 13 find_dectype call site: 00165 /src/mpg123/src/libmpg123/optimize.c:235
2 2 1 :

['strcasecmp']

2 2 INT123_dectype call site: 00058 /src/mpg123/src/libmpg123/optimize.c:927
0 303 3 :

['enc_chan_fit', 'INT123_frame_freq', 'rate2num']

0 317 INT123_frame_output_format call site: 00129 /src/mpg123/src/libmpg123/format.c:290
0 105 3 :

['imin', 'imax', 'cap_fit']

0 105 enc_chan_fit call site: 00118 /src/mpg123/src/libmpg123/format.c:194
0 54 2 :

['INT123_frame_exit', 'free']

0 54 mpg123_parnew call site: 00057 /src/mpg123/src/libmpg123/libmpg123.c:107
0 28 1 :

['INT123_frame_index_setup']

0 30 mpg123_param call site: 00073 /src/mpg123/src/libmpg123/libmpg123.c:170
0 20 1 :

['mpg123_grow_string']

0 20 store_id3_text call site: 00273 /src/mpg123/src/libmpg123/id3.c:345
0 10 2 :

['INT123_set_pointer', 'getbits']

0 10 halfspeed_do call site: 00228 /src/mpg123/src/libmpg123/parse.c:457
0 6 1 :

['mpg123_free_string']

16 157 process_extra call site: 00325 /src/mpg123/src/libmpg123/id3.c:695
0 6 1 :

['mpg123_free_string']

0 14 process_comment call site: 00295 /src/mpg123/src/libmpg123/id3.c:605

Runtime coverage analysis

Covered functions
189
Functions that are reachable but not covered
43
Reachable functions
192
Percentage of reachable functions covered
77.6%
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/decode_fuzzer.cc 1
/src/mpg123/src/libmpg123/libmpg123.c 19
/src/mpg123/./src/libmpg123/sample.h 1
/src/mpg123/src/libmpg123/frame.c 28
/src/mpg123/./src/libmpg123/getcpuflags.h 1
/src/mpg123/src/libmpg123/optimize.c 7
/src/mpg123/src/libmpg123/icy.c 3
/src/mpg123/src/libmpg123/id3.c 23
/src/mpg123/src/libmpg123/format.c 17
/src/mpg123/src/libmpg123/readers.c 13
/src/mpg123/src/libmpg123/stringbuf.c 6
/src/mpg123/src/libmpg123/index.c 7
/src/mpg123/src/compat/compat_str.c 1
/src/mpg123/src/libmpg123/layer3.c 2
/src/mpg123/./src/libmpg123/dither_impl.h 3
/src/mpg123/src/libmpg123/parse.c 20
/src/mpg123/src/libmpg123/ntom.c 7
/src/mpg123/src/libmpg123/tabinit.c 1
/src/mpg123/src/libmpg123/layer2.c 1
/src/mpg123/./src/libmpg123/gapless.h 1
/src/mpg123/./src/libmpg123/getbits.h 1
/src/mpg123/src/libmpg123/layer1.c 4

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
INT123_do_layer3 /src/mpg123/src/libmpg123/layer3.c 1 ['struct.mpg123_handle_struct *'] 2 0 1094 137 45 12 0 277 267
mpg123_open_fixed /src/mpg123/src/libmpg123/libmpg123.c 4 ['struct.mpg123_handle_struct *', 'char *', 'int ', 'int '] 7 0 64 9 4 152 0 1298 130
default_init /src/mpg123/src/libmpg123/readers.c 1 ['struct.mpg123_handle_struct *'] 1 0 333 45 16 14 0 91 85
mpg123_store_utf8_2 /src/mpg123/src/libmpg123/libmpg123.c 4 ['struct.mpg123_string *', 'int ', 'char *', 'size_t '] 7 0 28 3 2 16 0 85 49
INT123_do_layer2 /src/mpg123/src/libmpg123/layer2.c 1 ['struct.mpg123_handle_struct *'] 2 0 269 37 13 5 0 55 49
mpg123_feedseek /src/mpg123/src/libmpg123/libmpg123.c 4 ['struct.mpg123_handle_struct *', 'size_t ', 'int ', 'size_t *'] 8 0 299 43 14 126 0 1191 45
INT123_synth_ntom_s32_m2s /src/mpg123/./src/libmpg123/synth_ntom.h 2 ['N/A', 'struct.mpg123_handle_struct.376 *'] 1 0 77 7 3 3 0 45 45

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

Functions statically reachable by fuzzers
54.0%
247 / 458
Cyclomatic complexity statically reachable by fuzzers
66.0%
2134 / 3253

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/mpg123/./src/libmpg123/mpg123lib_intern.h [] []
/src/mpg123/./src/libmpg123/swap_bytes_impl.h [] []
/src/mpg123/src/libmpg123/ntom.c ['read_fuzzer', 'decode_fuzzer'] ['decode_fuzzer']
/src/mpg123/src/libmpg123/equalizer.c [] []
/src/mpg123/src/libmpg123/format.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/synth_real.c [] []
/src/mpg123/src/libmpg123/layer3.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/tabinit.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/stringbuf.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/./src/libmpg123/dither_impl.h ['read_fuzzer', 'decode_fuzzer'] []
/src/mpg123/./src/libmpg123/synth_ntom.h [] []
/src/mpg123/src/compat/compat.c ['read_fuzzer'] ['read_fuzzer']
/src/mpg123/./src/libmpg123/synth_mono.h [] []
/src/mpg123/./src/libmpg123/gapless.h ['read_fuzzer', 'decode_fuzzer'] []
/src/mpg123/./src/libmpg123/getcpuflags.h ['read_fuzzer', 'decode_fuzzer'] []
/src/mpg123/src/libmpg123/icy2utf8.c [] []
/src/mpg123/src/libmpg123/synth.c [] []
/src/mpg123/src/compat/compat_str.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/./src/libmpg123/sample.h ['read_fuzzer', 'decode_fuzzer'] []
/src/mpg123/./src/libmpg123/synth_8bit.h [] []
/src/decode_fuzzer.cc ['decode_fuzzer'] ['decode_fuzzer']
/src/mpg123/src/libmpg123/layer1.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/./src/libmpg123/synth.h [] []
/src/mpg123/src/libmpg123/parse.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/frame.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/optimize.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/readers.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/read_fuzzer.c ['read_fuzzer'] ['read_fuzzer']
/src/mpg123/src/libmpg123/libmpg123.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/layer2.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/id3.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/./src/libmpg123/getbits.h ['read_fuzzer', 'decode_fuzzer'] []
/usr/include/x86_64-linux-gnu/bits/byteswap.h [] []
/src/mpg123/src/libmpg123/icy.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/index.c ['read_fuzzer', 'decode_fuzzer'] ['read_fuzzer', 'decode_fuzzer']
/src/mpg123/src/libmpg123/dct64.c [] []
/src/mpg123/src/libmpg123/synth_s32.c [] []
/usr/local/bin/../include/c++/v1/stdexcept [] []

Directories in report

Directory
/src/mpg123/src/compat/
/src/mpg123/./src/libmpg123/
/src/
/usr/local/bin/../include/c++/v1/
/src/mpg123/src/libmpg123/
/usr/include/x86_64-linux-gnu/bits/