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

Table of contents

Project overview: libarchive
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: libarchive_fuzzer
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/libarchive_fuzzer.cc
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
Report generation date: 2026-05-30

Project overview: libarchive

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
66.0%
844 / 1286
Cyclomatic complexity statically reachable by fuzzers
74.0%
7492 / 10117
Runtime code coverage of functions
73.0%
941 / 1286

Warning: The number of runtime covered functions are larger than the number of reachable functions. This means that Fuzz Introspector found there are more functions covered at runtime than what is considered reachable based on the static analysis. This is a limitation in the analysis as anything covered at runtime is by definition reachable by the fuzzers.
This is likely due to a limitation in the static analysis. In this case, the count of functions covered at runtime is the true value, which means this is what should be considered "achieved" by the fuzzer.

Use the project functions table below to query all functions that were not covered at runtime.

Fuzzers overview

Fuzzer Fuzzer filename Functions Reached Functions unreached Fuzzer depth Files reached Basic blocks reached Cyclomatic complexity Details
libarchive_fuzzer /src/libarchive_fuzzer.cc 909 510 19 51 19988 7654 libarchive_fuzzer.cc

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: libarchive_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 distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 1618 35.8%
gold [1:9] 254 5.63%
yellow [10:29] 149 3.30%
greenyellow [30:49] 114 2.52%
lawngreen 50+ 2375 52.6%
All colors 4510 100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked Calltree index Parent function Callsite Largest blocked function
46 1943 xml_end call site: 01943 strcmp
43 2342 seek_pack call site: 02342 get_uncompressed_data
42 1866 xml_start call site: 01866 unknowntag_start
39 989 parse_file call site: 00989 archive_entry_linkify
30 2074 xattr_free call site: 02074 archive_set_error
29 4319 slurp_central_directory call site: 04319 expose_parent_dirs
27 4357 archive_read_format_zip_seekable_read_header call site: 04357 zip_read_mac_metadata
25 1041 archive_entry_clear call site: 01041 archive_entry_pathname
23 2296 extract_pack_stream call site: 02296 archive_set_error
22 1998 xml_data call site: 01998 strappend_base64
21 3709 parse_file_info call site: 03709 register_CE
20 283 iconv_strncat_in_locale call site: 00283 archive_string_normalize_D

Runtime coverage analysis

Covered functions
948
Functions that are reachable but not covered
165
Reachable functions
909
Percentage of reachable functions covered
81.85%
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.
Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.
Function name source code lines source lines hit percentage hit

Files reached

filename functions hit
/src/libarchive_fuzzer.cc 1
/src/libarchive/libarchive/archive_read.c 32
/src/libarchive/libarchive/archive_entry.c 99
/src/libarchive/libarchive/archive_read_support_filter_all.c 1
/src/libarchive/libarchive/archive_check_magic.c 6
/src/libarchive/libarchive/archive_util.c 5
/src/libarchive/libarchive/archive_string_sprintf.c 4
/src/libarchive/libarchive/archive_string.c 72
/src/libarchive/libarchive/archive_read_support_filter_bzip2.c 1
/src/libarchive/libarchive/archive_read_support_filter_compress.c 1
/src/libarchive/libarchive/archive_read_support_filter_gzip.c 1
/src/libarchive/libarchive/archive_read_support_filter_xz.c 3
/src/libarchive/libarchive/archive_read_support_filter_uu.c 1
/src/libarchive/libarchive/archive_read_support_filter_rpm.c 1
/src/libarchive/libarchive/archive_read_support_filter_lrzip.c 1
/src/libarchive/libarchive/archive_read_support_filter_lzop.c 1
/src/libarchive/libarchive/archive_read_support_filter_grzip.c 1
/src/libarchive/libarchive/archive_read_support_filter_lz4.c 1
/src/libarchive/libarchive/archive_read_support_filter_zstd.c 1
/src/libarchive/libarchive/archive_read_support_format_all.c 1
/src/libarchive/libarchive/archive_read_support_format_ar.c 11
/src/libarchive/libarchive/archive_read_support_format_cpio.c 8
/src/libarchive/libarchive/archive_endian.h 9
/src/libarchive/libarchive/archive_read_support_format_empty.c 4
/src/libarchive/libarchive/archive_read_support_format_lha.c 37
/src/libarchive/libarchive/archive_time.c 2
/src/libarchive/libarchive/archive_read_support_format_mtree.c 34
/src/libarchive/libarchive/archive_rb.c 11
/src/libarchive/libarchive/archive_entry_link_resolver.c 8
/src/libarchive/libarchive/archive_pack_dev.c 2
/src/libarchive/libarchive/archive_acl.c 14
/src/libarchive/libarchive/archive_entry_xattr.c 2
/src/libarchive/libarchive/archive_entry_sparse.c 2
/src/libarchive/libarchive/archive_read_support_format_tar.c 55
/src/libarchive/libarchive/archive_read_support_format_xar.c 48
/src/libarchive/libarchive/archive_read_support_format_warc.c 19
/src/libarchive/libarchive/archive_read_support_format_7zip.c 53
/src/libarchive/libarchive/archive_read_support_format_cab.c 43
/src/libarchive/libarchive/archive_read_support_format_rar.c 60
/src/libarchive/libarchive/archive_read_support_format_rar5.c 100
/src/libarchive/libarchive/archive_blake2sp_ref.c 6
/src/libarchive/libarchive/archive_blake2_impl.h 5
/src/libarchive/libarchive/archive_blake2s_ref.c 9
/src/libarchive/libarchive/archive_read_support_format_iso9660.c 50
/src/libarchive/libarchive/archive_read_support_format_zip.c 46
/src/libarchive/libarchive/archive_read_add_passphrase.c 7
/src/libarchive/libarchive/archive_virtual.c 5
/src/libarchive/libarchive/archive_read_support_format_raw.c 6
/src/libarchive/libarchive/archive_read_set_options.c 4
/src/libarchive/libarchive/archive_options.c 3
/src/libarchive/libarchive/archive_read_open_memory.c 7

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
parse_file /src/libarchive/libarchive/archive_read_support_format_mtree.c 5 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 10 0 854 155 55 158 0 1055 267
Ppmd7_EncodeSymbol /src/libarchive/libarchive/archive_ppmd7.c 3 ['N/A', 'N/A', 'int'] 7 0 737 58 17 23 0 149 149
archive_entry_acl_from_text_w /src/libarchive/libarchive/archive_entry.c 3 ['N/A', 'N/A', 'int'] 8 0 22 3 2 28 0 211 138
read_mtree /src/libarchive/libarchive/archive_read_support_format_mtree.c 2 ['N/A', 'N/A'] 10 0 360 65 24 54 0 426 97
uudecode_filter_read /src/libarchive/libarchive/archive_read_support_filter_uu.c 2 ['N/A', 'N/A'] 7 0 1265 184 69 29 0 239 83
grzip_bidder_init /src/libarchive/libarchive/archive_read_support_filter_grzip.c 1 ['N/A'] 6 0 24 3 2 40 0 168 80
_archive_entry_acl_text_l /src/libarchive/libarchive/archive_entry.c 5 ['N/A', 'int', 'N/A', 'N/A', 'N/A'] 11 0 58 6 3 80 0 665 74
lz4_filter_read /src/libarchive/libarchive/archive_read_support_filter_lz4.c 2 ['N/A', 'N/A'] 9 0 258 40 12 34 0 225 71
XXH32_update /src/libarchive/libarchive/xxhash.c 3 ['N/A', 'N/A', 'int'] 1 0 1717 180 61 2 0 65 65
header_odc /src/libarchive/libarchive/archive_read_support_format_cpio.c 5 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 9 0 162 12 6 45 0 236 60

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

Functions statically reachable by fuzzers
74.0%
949 / 1286
Cyclomatic complexity statically reachable by fuzzers
84.0%
8538 / 10117

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.

/src/libarchive_fuzzer.cc

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=['xml_end', 'seek_pack', 'xml_start', 'parse_file', 'xattr_free', 'slurp_central_directory', 'archive_read_format_zip_seekable_read_header', 'archive_entry_clear', 'extract_pack_stream', 'xml_data']

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
is_nfs4_perms 54 24 44.44% ['libarchive_fuzzer']
archive_entry_linkresolver_set_strategy 33 8 24.24% ['libarchive_fuzzer']
_archive_set_options 56 23 41.07% ['libarchive_fuzzer']
bzip2_filter_read 105 48 45.71% ['libarchive_fuzzer']
consume_header 58 27 46.55% ['libarchive_fuzzer']
lz4_filter_read 69 27 39.13% ['libarchive_fuzzer']
lzip_tail 41 20 48.78% ['libarchive_fuzzer']
set_error 40 9 22.5% ['libarchive_fuzzer']
zstd_bidder_bid 36 18 50.0% ['libarchive_fuzzer']
archive_read_format_7zip_read_header 168 76 45.23% ['libarchive_fuzzer']
read_stream 77 39 50.64% ['libarchive_fuzzer']
extract_pack_stream 129 69 53.48% ['libarchive_fuzzer']
decompress 115 32 27.82% ['libarchive_fuzzer']
case_7Z_LZMA2 224 28 12.5%
get_uncompressed_data 38 16 42.10% ['libarchive_fuzzer']
setup_decode_folder 200 29 14.49% ['libarchive_fuzzer']
init_decompression 39 17 43.58% ['libarchive_fuzzer']
free_decompression 35 18 51.42% ['libarchive_fuzzer']
isEVD 43 10 23.25% ['libarchive_fuzzer']
read_CE 39 11 28.20% ['libarchive_fuzzer']
lha_read_file_extended_header 259 119 45.94% ['libarchive_fuzzer']
lzh_make_huffman_table 151 83 54.96% ['libarchive_fuzzer']
readline 56 22 39.28% ['libarchive_fuzzer']
parse_escapes 70 38 54.28% ['libarchive_fuzzer']
parse_file 152 38 25.0% ['libarchive_fuzzer']
parse_digest 51 19 37.25% ['libarchive_fuzzer']
read_data 39 11 28.20% ['libarchive_fuzzer']
archive_read_format_tar_options 31 14 45.16% ['libarchive_fuzzer']
header_pax_extension 215 112 52.09% ['libarchive_fuzzer']
pax_attribute 487 146 29.97% ['libarchive_fuzzer']
xar_read_header 168 17 10.11% ['libarchive_fuzzer']
read_toc 100 30 30.0% ['libarchive_fuzzer']
xml_end 325 110 33.84% ['libarchive_fuzzer']
xml_data 271 132 48.70% ['libarchive_fuzzer']
decompression_init 120 19 15.83% ['libarchive_fuzzer']
archive_read_format_zip_options 38 15 39.47% ['libarchive_fuzzer']
read_decryption_header 150 67 44.66% ['libarchive_fuzzer']
get_sconv_object 33 17 51.51% ['libarchive_fuzzer']
setup_converter 84 28 33.33% ['libarchive_fuzzer']

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/libarchive/libarchive/archive_read_support_format_rar.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_acl.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_check_magic.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_cryptor.c [] []
/src/libarchive/libarchive/archive_read_support_filter_lrzip.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/usr/local/bin/../include/c++/v1/stdexcept [] []
/src/libarchive/libarchive/archive_blake2sp_ref.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_raw.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/xxhash.c [] []
/src/libarchive/libarchive/archive_entry_sparse.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_empty.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_time.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_all.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_gzip.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_xar.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_set_options.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_zstd.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_rar5.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_ppmd8.c [] []
/src/libarchive/libarchive/archive_hmac.c [] []
/src/libarchive/libarchive/archive_blake2_impl.h ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_open_memory.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_zip.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_rpm.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_string_sprintf.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_entry.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_xz.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_tar.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_grzip.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_endian.h ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_ar.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_util.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_mtree.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive_fuzzer.cc ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_cab.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_program.c [] []
/src/libarchive/libarchive/archive_read_support_filter_uu.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_lha.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_all.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_pack_dev.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/filter_fork_posix.c [] []
/src/libarchive/libarchive/archive_read_support_filter_compress.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_warc.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_digest.c [] []
/src/libarchive/libarchive/archive_read_support_filter_lz4.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_blake2s_ref.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_string.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_options.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_ppmd7.c [] []
/src/libarchive/libarchive/archive_rb.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_7zip.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_iso9660.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_lzop.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_virtual.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_add_passphrase.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_cmdline.c [] []
/src/libarchive/libarchive/archive_read_support_format_cpio.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_entry_xattr.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_bzip2.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_entry_link_resolver.c ['libarchive_fuzzer'] ['libarchive_fuzzer']

Directories in report

Directory
/usr/local/bin/../include/c++/v1/
/src/
/src/libarchive/libarchive/

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
libarchive_fuzzer fuzzerLogFile-0-79Lb2VmVzD.data fuzzerLogFile-0-79Lb2VmVzD.data.yaml libarchive_fuzzer.covreport