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

Table of contents

Project overview: netcdf
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: fuzz_open
Call tree
Fuzz blockers
Runtime coverage analysis
Files reached
Analyses and suggestions
Optimal target analysis
Remaining optimal interesting functions
All functions overview
Runtime coverage analysis
Complex functions with low coverage
Files and Directories in report
Files in report
Directories in report
Metadata section
Report generation date: 2022-11-18

Project overview: netcdf

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
8.59%
196/2281
Cyclomatic complexity statically reachable by fuzzers
10.02%
1428/14257
Functions covered at runtime
173

Fuzzers overview

Fuzzer Fuzzer filename Functions Reached Functions unreached Fuzzer depth Files reached Basic blocks reached Cyclomatic complexity Details
fuzz_open fuzz/fuzz_open.c 196 2086 15 28 3606 1428 fuzz_open.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: fuzz_open

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 0 580 73.0%
gold [1:9] 152 19.1%
yellow [10:29] 10 1.25%
greenyellow [30:49] 36 4.53%
lawngreen 50+ 16 2.01%
All colors 794 100

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
2219 2380 18 :

['parseonchar', 'ncurifragmentparams', 'ncurisetfragments', 'processmacros', 'NCpathcanonical', 'ncurisetpath', 'ncuribuild', 'nclistget', 'processfragmentkeys', 'strcmp', 'ncurifragmentlookup', 'processinferences', 'envvlist2string', 'NC_iss3', 'NC_s3urlrebuild', 'NCpathabsolute', 'cleanfragments', 'processmodearg']

2219 2854 NC_infermodel call site /src/netcdf-c/libdispatch/dinfermodel.c:837
366 373 9 :

['calloc', 'strdup', 'strlen', 'ensurequerylist', 'strchr', 'strcmp', 'nclocate', 'ensurefraglist', 'ncuridecode']

378 413 ncuriparse call site /src/netcdf-c/libdispatch/ncuri.c:251
202 277 9 :

['parseonchar', 'ncurifragmentparams', 'parsepair', 'strdup', 'ncurisetprotocol', 'nclistnew', 'nclistget', 'strcmp', 'nclistpush']

202 355 processuri call site /src/netcdf-c/libdispatch/dinfermodel.c:245
101 119 2 :

['locate', 'rehash']

101 119 NC_hashmapadd call site /src/netcdf-c/libdispatch/nchashmap.c:205
84 84 1 :

['readfile']

98 266 memio_open call site /src/netcdf-c/libsrc/memio.c:349
58 58 2 :

['NC_readfileF', 'fclose']

58 58 NC_readfilen call site /src/netcdf-c/libdispatch/dutil.c:272
35 52 3 :

['parselist', 'nclistpush', 'nclistextract']

415 467 ncuriparse call site /src/netcdf-c/libdispatch/ncuri.c:236
24 24 1 :

['writefile']

24 24 memio_close call site /src/netcdf-c/libsrc/memio.c:523
20 20 1 :

['collectprefixparams']

503 624 ncuriparse call site /src/netcdf-c/libdispatch/ncuri.c:187
17 33 5 :

['nclistfree', 'ncpsharedlibfree', 'NCZ_unload_plugin', 'nclistget', 'free']

17 33 NCZ_filter_finalize call site /src/netcdf-c/libnczarr/zfilter.c:770
14 47 4 :

['strcasecmp', 'nclistpush', 'nclistremove', 'nclistget']

14 47 removedups call site /src/netcdf-c/libdispatch/ncuri.c:1235
12 12 2 :

['freestringvec', 'free']

12 12 ncurifree call site /src/netcdf-c/libdispatch/ncuri.c:466

Runtime coverage analysis

Covered functions
173
Functions that are reachable but not covered
105
Reachable functions
196
Percentage of reachable functions covered
46.43%
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/fuzz_open.c 1
libdispatch/dfile.c 3
liblib/nc_initialize.c 3
libdispatch/ddispatch.c 2
libsrc4/nc4internal.c 3
libdispatch/nclist.c 11
libdispatch/dpathmgr.c 10
libdispatch/dstring.c 1
libdispatch/nclog.c 7
libdispatch/drc.c 27
libdispatch/ncbytes.c 10
libdispatch/dutil.c 6
libdispatch/ncuri.c 25
libdispatch/ds3util.c 3
libdispatch/dauth.c 1
libdispatch/doffsets.c 1
libsrc/nc3dispatch.c 2
libsrc4/nc4dispatch.c 2
libnczarr/zdispatch.c 2
libnczarr/zinternal.c 2
libnczarr/zprov.c 3
libnczarr/zarr.c 1
libnczarr/zfilter.c 2
libncpoco/ncpoco.c 1
libdispatch/dinfermodel.c 28
libdispatch/derror.c 1
libdispatch/nc.c 4
libdispatch/nclistmgr.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
NCZ_open /src/netcdf-c/libnczarr/zopen.c 7 ['char *', 'int ', 'int ', 'size_t *', 'char *', 'struct.NC_Dispatch.138 *', 'int '] 15 0 133 24 9 402 0 3593 2794
NC3_put_vara /src/netcdf-c/build/libsrc/putget.c 6 ['int ', 'int ', 'size_t *', 'size_t *', 'char *', 'int '] 5 0 532 75 29 343 0 1911 1657
NC3_get_vara /src/netcdf-c/build/libsrc/putget.c 6 ['int ', 'int ', 'size_t *', 'size_t *', 'char *', 'int '] 5 0 516 73 28 304 0 1566 1424
NCZ_get_vara /src/netcdf-c/libnczarr/zvar.c 6 ['int ', 'int ', 'size_t *', 'size_t *', 'char *', 'int '] 12 0 36 3 2 305 0 2718 826
NC3_open /src/netcdf-c/libsrc/nc3internal.c 7 ['char *', 'int ', 'int ', 'size_t *', 'char *', 'struct.NC_Dispatch.16 *', 'int '] 9 0 207 32 11 181 0 994 766
NC3_def_var_fill /src/netcdf-c/libsrc/var.c 4 ['int ', 'int ', 'int ', 'char *'] 8 0 194 30 13 266 0 1461 578
NC3_get_att /src/netcdf-c/build/libsrc/attr.c 5 ['int ', 'int ', 'char *', 'char *', 'int '] 6 0 341 42 11 221 0 1084 293

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

Functions statically reachable by fuzzers
61.64%
1406/2281
Cyclomatic complexity statically reachable by fuzzers
68.5%
9766 / 14257

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

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
NC_infermodel 104 37 35.57% ['fuzz_open']
processuri 57 19 33.33% ['fuzz_open']
NC_omodeinfer 40 14 35.0% ['fuzz_open']
pathinit 39 17 43.58% ['fuzz_open']
parsepath 63 32 50.79% ['fuzz_open']
unparsepath 190 33 17.36% ['fuzz_open']
locate 36 18 50.0% []
ncuriparse 205 53 25.85% ['fuzz_open']
memio_pad_length 31 7 22.58% []
NC_check_vlens 64 27 42.18% []
NC3_close 47 25 53.19% []
NC_var_shape 44 15 34.09% []

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/netcdf-c/libdispatch/dattput.c [] []
/src/netcdf-c/libsrc/nc3dispatch.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libnczarr/zutil.c [] []
/src/netcdf-c/build/libsrc/attr.c [] []
/src/netcdf-c/libsrc4/ncfunc.c [] []
/src/netcdf-c/libnczarr/zinternal.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/nclist.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/dvarget.c [] []
/src/netcdf-c/libsrc4/ncindex.c [] []
/src/netcdf-c/libsrc/posixio.c [] []
/src/netcdf-c/libdispatch/nclog.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libsrc/var.c [] []
/src/netcdf-c/libdispatch/ncbytes.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/dtype.c [] []
/src/netcdf-c/libdispatch/ncexhash.c [] []
/src/netcdf-c/libnczarr/zsync.c [] []
/src/netcdf-c/libdispatch/dnotnc4.c [] []
/src/netcdf-c/libdispatch/dattget.c [] []
/src/netcdf-c/libdispatch/ddim.c [] []
/src/netcdf-c/libdispatch/dcompound.c [] []
/src/netcdf-c/libncpoco/ncpoco.c ['fuzz_open'] []
/src/netcdf-c/libnczarr/zchunking.c [] []
/src/netcdf-c/libnczarr/zcvt.c [] []
/src/netcdf-c/libnczarr/zarr.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/derror.c ['fuzz_open'] []
/src/netcdf-c/libdispatch/drc.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/dpathmgr.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libsrc4/nc4type.c [] []
/src/netcdf-c/libdispatch/dfilter.c [] []
/src/netcdf-c/libsrc4/nc4dim.c [] []
/src/netcdf-c/libnczarr/zdim.c [] []
/src/netcdf-c/libdispatch/dgroup.c [] []
/src/netcdf-c/libdispatch/doffsets.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libnczarr/zmap.c [] []
/src/netcdf-c/fuzz/fuzz_open.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libnczarr/zgrp.c [] []
/src/netcdf-c/libsrc/v1hpg.c [] []
/src/netcdf-c/libdispatch/ncuri.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/dauth.c ['fuzz_open'] []
/src/netcdf-c/libnczarr/zodom.c [] []
/src/netcdf-c/libsrc/nc3internal.c [] []
/src/netcdf-c/libnczarr/zopen.c [] []
/src/netcdf-c/libnczarr/zprov.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/dstring.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libsrc/mmapio.c [] []
/src/netcdf-c/libnczarr/zxcache.c [] []
/src/netcdf-c/libdispatch/dfile.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libnczarr/zdispatch.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libnczarr/zattr.c [] []
/src/netcdf-c/libnczarr/ztype.c [] []
/src/netcdf-c/libdispatch/utf8proc.c [] []
/src/netcdf-c/libsrc/dim.c [] []
/src/netcdf-c/libsrc4/nc4dispatch.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/ncjson.c [] []
/src/netcdf-c/libdispatch/ddispatch.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/ncxcache.c [] []
/src/netcdf-c/libdispatch/ds3util.c ['fuzz_open'] []
/src/netcdf-c/libnczarr/zvar.c [] []
/src/netcdf-c/libdispatch/dinstance.c [] []
/src/netcdf-c/liblib/nc_initialize.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/nc.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libnczarr/zfile.c [] []
/src/netcdf-c/libsrc4/nc4internal.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/build/libsrc/putget.c [] []
/src/netcdf-c/libnczarr/zcreate.c [] []
/src/netcdf-c/libsrc4/nc4grp.c [] []
/src/netcdf-c/libsrc4/nc4attr.c [] []
/src/netcdf-c/libdispatch/dvarput.c [] []
/src/netcdf-c/libncpoco/cp_unix.c [] []
/src/netcdf-c/libsrc/ncio.c [] []
/src/netcdf-c/build/libsrc/ncx.c [] []
/src/netcdf-c/libnczarr/zmap_file.c [] []
/src/netcdf-c/libnczarr/zdebug.c [] []
/src/netcdf-c/libsrc4/nc4var.c [] []
/src/netcdf-c/libdispatch/nclistmgr.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libsrc/memio.c [] []
/src/netcdf-c/libdispatch/dvarinq.c [] []
/src/netcdf-c/libnczarr/zfilter.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/nchashmap.c [] []
/src/netcdf-c/libdispatch/dcrc64.c [] []
/src/netcdf-c/libnczarr/zwalk.c [] []
/src/netcdf-c/libdispatch/dutil.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/dvar.c [] []
/src/netcdf-c/libnczarr/zclose.c [] []
/src/netcdf-c/libdispatch/dutf8.c [] []
/src/netcdf-c/libdispatch/dinfermodel.c ['fuzz_open'] ['fuzz_open']
/src/netcdf-c/libdispatch/dattinq.c [] []

Directories in report

Directory
/src/netcdf-c/libnczarr/
/src/netcdf-c/fuzz/
/src/netcdf-c/libncpoco/
/src/netcdf-c/libdispatch/
/src/netcdf-c/libsrc4/
/src/netcdf-c/build/libsrc/
/src/netcdf-c/libsrc/
/src/netcdf-c/liblib/

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
fuzz_open fuzzerLogFile-0-7TjSfOMeXg.data fuzzerLogFile-0-7TjSfOMeXg.data.yaml fuzz_open.covreport