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

Table of contents

Project overview: unbound
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: fuzz_1_fuzzer
Call tree
Fuzzer: parse_packet_fuzzer
Call tree
Fuzzer: fuzz_3_fuzzer
Call tree
Fuzzer: fuzz_4_fuzzer
Call tree
Fuzzer: fuzz_2_fuzzer
Call tree
Analyses and suggestions
Optimal target analysis
Remaining optimal interesting functions
All functions overview
Fuzz engine guidance
fuzz_1.c
Dictionary
Fuzzer function priority
parse_packet_fuzzer.c
Dictionary
Fuzzer function priority
fuzz_3.c
Dictionary
Fuzzer function priority
fuzz_4.c
Dictionary
Fuzzer function priority
fuzz_2.c
Dictionary
Fuzzer function priority
Runtime coverage analysis
Files and Directories in report
Files in report
Directories in report
Metadata section
Report generation date: 2025-10-28

Project overview: unbound

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
14.0%
353 / 2581
Cyclomatic complexity statically reachable by fuzzers
11.0%
2411 / 21157
Runtime code coverage of functions
0.0%
0 / 2581

Fuzzers overview

Fuzzer Fuzzer filename Functions Reached Functions unreached Fuzzer depth Files reached Basic blocks reached Cyclomatic complexity Details
fuzz_1_fuzzer fuzz_1.c 193 2619 9 24 2750 1153 fuzz_1.c
parse_packet_fuzzer parse_packet_fuzzer.c 74 2738 7 8 771 353 parse_packet_fuzzer.c
fuzz_3_fuzzer fuzz_3.c 95 2717 6 8 1483 668 fuzz_3.c
fuzz_4_fuzzer fuzz_4.c 239 2573 9 27 3279 1382 fuzz_4.c
fuzz_2_fuzzer fuzz_2.c 112 2700 7 6 1354 561 fuzz_2.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 Runtime reached by Fuzzers Combined 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_1_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

Full calltree

Call tree overview bitmap:

The project has no code coverage. Will not display blockers as blockers depend on code coverage.

Fuzzer: parse_packet_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

Full calltree

Call tree overview bitmap:

The project has no code coverage. Will not display blockers as blockers depend on code coverage.

Fuzzer: fuzz_3_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

Full calltree

Call tree overview bitmap:

The project has no code coverage. Will not display blockers as blockers depend on code coverage.

Fuzzer: fuzz_4_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

Full calltree

Call tree overview bitmap:

The project has no code coverage. Will not display blockers as blockers depend on code coverage.

Fuzzer: fuzz_2_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

Full calltree

Call tree overview bitmap:

The project has no code coverage. Will not display blockers as blockers depend on code coverage.

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
ub_resolve_async /src/unbound/libunbound/libunbound.c 7 ['N/A', 'N/A', 'int', 'int', 'N/A', 'N/A', 'N/A'] 27 0 439 86 23 1356 0 9049 6939
iter_operate /src/unbound/iterator/iterator.c 4 ['N/A', 'int', 'int', 'N/A'] 17 0 221 34 14 882 0 6369 2962
config_read /src/unbound/util/config_file.c 3 ['N/A', 'N/A', 'N/A'] 7 0 253 41 17 113 2 1562 1379
auth_zones_notify /src/unbound/services/authzone.c 10 ['N/A', 'N/A', 'N/A', 'size_t', 'short', 'N/A', 'int', 'int', 'int', 'N/A'] 43 0 182 33 9 1077 0 7517 1212
val_operate /src/unbound/validator/validator.c 4 ['N/A', 'int', 'int', 'N/A'] 24 0 350 48 20 857 0 6034 971
val_init /src/unbound/validator/validator.c 2 ['N/A', 'int'] 16 0 141 24 8 417 0 2683 622
ub_ctx_set_option /src/unbound/libunbound/libunbound.c 3 ['N/A', 'N/A', 'N/A'] 6 0 135 28 8 62 0 855 557

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

Functions statically reachable by fuzzers
74.0%
1913 / 2581
Cyclomatic complexity statically reachable by fuzzers
79.0%
16792 / 21157

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 Runtime reached by Fuzzers Combined 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.

fuzz_1.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag


parse_packet_fuzzer.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag


fuzz_3.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag


fuzz_4.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag


fuzz_2.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag


Runtime coverage analysis

No runtime coverage data was found

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/unbound/util/ub_event.c ['fuzz_4_fuzzer'] []
/src/unbound/util/data/packed_rrset.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/sldns/sbuffer.c ['fuzz_1_fuzzer', 'parse_packet_fuzzer', 'fuzz_3_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/compat/chacha_private.h [] []
/src/unbound/validator/val_secalgo.c [] []
/src/unbound/validator/autotrust.c [] []
/src/unbound/validator/val_utils.c [] []
/src/unbound/util/data/msgencode.c [] []
/src/unbound/libunbound/libworker.c [] []
/src/unbound/iterator/iter_donotq.c [] []
/src/unbound/./sldns/sbuffer.h ['fuzz_1_fuzzer', 'parse_packet_fuzzer', 'fuzz_3_fuzzer', 'fuzz_4_fuzzer', 'fuzz_2_fuzzer'] []
/src/unbound/sldns/str2wire.c ['fuzz_3_fuzzer'] []
/src/unbound/util/alloc.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/respip/respip.c [] []
/src/unbound/validator/val_kentry.c [] []
/src/unbound/services/mesh.c [] []
/src/unbound/fuzz_4.c ['fuzz_4_fuzzer'] []
/src/unbound/fuzz_1.c ['fuzz_1_fuzzer'] []
/src/unbound/ [] []
/src/unbound/util/configparser.c [] []
/src/unbound/sldns/parseutil.c ['fuzz_1_fuzzer', 'fuzz_3_fuzzer', 'fuzz_4_fuzzer', 'fuzz_2_fuzzer'] []
/src/unbound/util/tube.c [] []
/src/unbound/util/timeval_func.c [] []
/src/unbound/util/module.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/util/edns.c [] []
/src/unbound/compat/arc4random_uniform.c [] []
/src/unbound/compat/arc4_lock.c [] []
/src/unbound/iterator/iter_hints.c [] []
/src/unbound/util/fptr_wlist.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/util/config_file.c [] []
/src/unbound/services/modstack.c [] []
/src/unbound/services/cache/infra.c [] []
/src/unbound/compat/strlcpy.c ['fuzz_1_fuzzer', 'fuzz_3_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/util/rbtree.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/validator/val_nsec3.c [] []
/src/unbound/services/rpz.c [] []
/src/unbound/util/storage/lruhash.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/util/siphash.c [] []
/src/unbound/services/outside_network.c [] []
/src/unbound/util/tcp_conn_limit.c [] []
/src/unbound/fuzz_2.c ['fuzz_2_fuzzer'] []
/src/unbound/services/view.c [] []
/src/unbound/iterator/iter_utils.c [] []
/src/unbound/compat/strlcat.c [] []
/src/unbound/sldns/keyraw.c ['fuzz_2_fuzzer'] []
/src/unbound/iterator/iter_delegpt.c [] []
/src/unbound/validator/val_kcache.c [] []
/src/unbound/sldns/parse.c ['fuzz_3_fuzzer'] []
/src/unbound/util/data/msgreply.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/iterator/iter_fwd.c [] []
/src/unbound/./util/configlexer.lex [] []
/src/unbound/parse_packet_fuzzer.c ['parse_packet_fuzzer'] []
/src/unbound/util/log.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/services/cache/dns.c [] []
/src/unbound/services/outbound_list.c [] []
/src/unbound/validator/val_anchor.c [] []
/src/unbound/util/regional.c ['fuzz_1_fuzzer', 'parse_packet_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/iterator/iterator.c [] []
/src/unbound/validator/validator.c [] []
/src/unbound/libunbound/libunbound.c [] []
/src/unbound/services/authzone.c [] []
/src/unbound/util/mini_event.c ['fuzz_4_fuzzer'] []
/src/unbound/libunbound/context.c [] []
/src/unbound/iterator/iter_scrub.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/dns64/dns64.c [] []
/src/unbound/util/data/msgparse.c ['fuzz_1_fuzzer', 'parse_packet_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/services/localzone.c [] []
/src/unbound/fuzz_3.c ['fuzz_3_fuzzer'] []
/src/unbound/util/net_help.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/util/data/dname.c ['fuzz_1_fuzzer', 'parse_packet_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/util/random.c [] []
/src/unbound/services/cache/rrset.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/sldns/wire2str.c ['fuzz_2_fuzzer'] []
/src/unbound/util/rfc_1982.c [] []
/src/unbound/util/storage/dnstree.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/util/storage/lookup3.c ['fuzz_1_fuzzer', 'parse_packet_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/iterator/iter_resptype.c [] []
/src/unbound/compat/arc4random.c [] []
/src/unbound/util/rtt.c [] []
/src/unbound/validator/val_sigcrypt.c [] []
/src/unbound/validator/val_neg.c [] []
/src/unbound/./util/configparser.y [] []
/src/unbound/util/timehist.c [] []
/src/unbound/util/storage/slabhash.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/sldns/rrdef.c ['fuzz_1_fuzzer', 'parse_packet_fuzzer', 'fuzz_3_fuzzer', 'fuzz_4_fuzzer', 'fuzz_2_fuzzer'] []
/src/unbound/util/netevent.c ['fuzz_4_fuzzer'] []
/src/unbound/iterator/iter_priv.c ['fuzz_1_fuzzer', 'fuzz_4_fuzzer'] []
/src/unbound/services/listen_dnsport.c [] []
/src/unbound/util/proxy_protocol.c [] []
/src/unbound/validator/val_nsec.c [] []
/src/unbound/util/locks.c [] []

Directories in report

Directory
/src/unbound/sldns/
/src/unbound/dns64/
/src/unbound/libunbound/
/src/unbound/util/data/
/src/unbound/./sldns/
/src/unbound/
/src/unbound/validator/
/src/unbound/services/
/src/unbound/./util/
/src/unbound/services/cache/
/src/unbound/util/storage/
/src/unbound/compat/
/src/unbound/respip/
/src/unbound/iterator/
/src/unbound/util/

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_1_fuzzer fuzzerLogFile-0-5zPYPhsTcW.data fuzzerLogFile-0-5zPYPhsTcW.data.yaml
parse_packet_fuzzer fuzzerLogFile-0-8HnzewGzhk.data fuzzerLogFile-0-8HnzewGzhk.data.yaml
fuzz_3_fuzzer fuzzerLogFile-0-f0qYhlfLsL.data fuzzerLogFile-0-f0qYhlfLsL.data.yaml
fuzz_4_fuzzer fuzzerLogFile-0-gKzioL3muA.data fuzzerLogFile-0-gKzioL3muA.data.yaml
fuzz_2_fuzzer fuzzerLogFile-0-y5tZswz75q.data fuzzerLogFile-0-y5tZswz75q.data.yaml