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: 2026-04-12

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%
7428 / 10069
Runtime code coverage of functions
73.0%
943 / 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 909 511 19 51 19849 7590 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 1724 38.3%
gold [1:9] 381 8.48%
yellow [10:29] 208 4.63%
greenyellow [30:49] 111 2.47%
lawngreen 50+ 2068 46.0%
All colors 4492 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 1938 xml_end call site: 01938 strcmp
42 1861 xml_start call site: 01861 unknowntag_start
42 2330 seek_pack call site: 02330 get_uncompressed_data
41 1382 pax_attribute call site: 01382 pax_attribute_read_number
39 986 parse_file call site: 00986 archive_entry_linkify
30 2065 xattr_free call site: 02065 archive_set_error
29 4300 slurp_central_directory call site: 04300 expose_parent_dirs
27 4338 archive_read_format_zip_seekable_read_header call site: 04338 zip_read_mac_metadata
25 1038 archive_entry_clear call site: 01038 archive_entry_pathname
24 2248 archive_read_format_7zip_read_header call site: 02248 header_bytes
22 1993 xml_data call site: 01993 strappend_base64
21 2287 decompress call site: 02287 archive_set_error

Runtime coverage analysis

Covered functions
950
Functions that are reachable but not covered
153
Reachable functions
909
Percentage of reachable functions covered
83.17%
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 33
/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 54
/src/libarchive/libarchive/archive_read_support_format_xar.c 49
/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 269
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 0 207 134
archive_entry_acl_text_w /src/libarchive/libarchive/archive_entry.c 2 ['N/A', 'int'] 11 0 51 6 3 84 0 714 106
read_mtree /src/libarchive/libarchive/archive_read_support_format_mtree.c 2 ['N/A', 'N/A'] 10 0 360 65 24 55 0 427 97
grzip_bidder_init /src/libarchive/libarchive/archive_read_support_filter_grzip.c 1 ['N/A'] 6 0 24 3 2 42 0 173 83
uudecode_filter_read /src/libarchive/libarchive/archive_read_support_filter_uu.c 2 ['N/A', 'N/A'] 7 0 1265 184 69 30 0 240 83
lz4_filter_read /src/libarchive/libarchive/archive_read_support_filter_lz4.c 2 ['N/A', 'N/A'] 9 0 258 40 12 35 0 226 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 46 0 238 56

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

Functions statically reachable by fuzzers
74.0%
950 / 1286
Cyclomatic complexity statically reachable by fuzzers
84.0%
8501 / 10069

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', 'xml_start', 'seek_pack', 'pax_attribute', 'parse_file', 'xattr_free', 'slurp_central_directory', 'archive_read_format_zip_seekable_read_header', 'archive_entry_clear', 'archive_read_format_7zip_read_header']

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
archive_entry_linkresolver_set_strategy 33 8 24.24% ['libarchive_fuzzer']
_archive_set_options 56 23 41.07% ['libarchive_fuzzer']
bzip2_filter_read 98 43 43.87% ['libarchive_fuzzer']
consume_header 46 22 47.82% ['libarchive_fuzzer']
lz4_filter_read 69 27 39.13% ['libarchive_fuzzer']
lzip_tail 41 18 43.90% ['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 162 76 46.91% ['libarchive_fuzzer']
read_stream 77 40 51.94% ['libarchive_fuzzer']
decompress 115 32 27.82% ['libarchive_fuzzer']
case_7Z_LZMA2 224 28 12.5%
setup_decode_folder 181 29 16.02% ['libarchive_fuzzer']
init_decompression 38 17 44.73% ['libarchive_fuzzer']
free_decompression 35 18 51.42% ['libarchive_fuzzer']
_ar_read_header 142 69 48.59% ['libarchive_fuzzer']
cab_consume_cfdata 80 30 37.5% ['libarchive_fuzzer']
archive_read_format_cab_read_data_skip 34 16 47.05% ['libarchive_fuzzer']
isEVD 43 10 23.25% ['libarchive_fuzzer']
read_CE 39 11 28.20% ['libarchive_fuzzer']
lha_read_file_extended_header 259 108 41.69% ['libarchive_fuzzer']
lzh_make_huffman_table 151 83 54.96% ['libarchive_fuzzer']
parse_file 152 37 24.34% ['libarchive_fuzzer']
parse_keyword 248 67 27.01% ['libarchive_fuzzer']
mtree_atol 40 18 45.0% ['libarchive_fuzzer']
parse_digest 51 16 31.37% ['libarchive_fuzzer']
read_data 39 11 28.20% ['libarchive_fuzzer']
archive_read_format_rar_seek_data 128 39 30.46% ['libarchive_fuzzer']
parse_file_extra_redir 56 29 51.78% ['libarchive_fuzzer']
archive_read_format_tar_options 31 14 45.16% ['libarchive_fuzzer']
header_pax_extension 213 98 46.00% ['libarchive_fuzzer']
pax_attribute 467 89 19.05% ['libarchive_fuzzer']
gnu_sparse_10_atol 31 13 41.93% ['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 218 119 54.58% ['libarchive_fuzzer']
parse_time 49 9 18.36% ['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 65 43.33% ['libarchive_fuzzer']
get_sconv_object 33 18 54.54% ['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_filter_compress.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_gzip.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_rb.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_digest.c [] []
/src/libarchive/libarchive/archive_read_support_format_tar.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_blake2_impl.h ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_xz.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_bzip2.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_empty.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_warc.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_add_passphrase.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_set_options.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_grzip.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_lz4.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_virtual.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_entry_link_resolver.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_open_memory.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_rar.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_ar.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_raw.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_endian.h ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_lha.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_hmac.c [] []
/src/libarchive/libarchive/archive_check_magic.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_util.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/filter_fork_posix.c [] []
/src/libarchive/libarchive/archive_cmdline.c [] []
/src/libarchive/libarchive/archive_read_support_format_iso9660.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_time.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_pack_dev.c ['libarchive_fuzzer'] []
/src/libarchive/libarchive/archive_acl.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_mtree.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_entry_sparse.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_lzop.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_cab.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_blake2sp_ref.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_options.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_string_sprintf.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_lrzip.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/xxhash.c [] []
/src/libarchive/libarchive/archive_read_support_filter_uu.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_entry.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_entry_xattr.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_all.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_filter_rpm.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_all.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_ppmd7.c [] []
/usr/local/bin/../include/c++/v1/stdexcept [] []
/src/libarchive/libarchive/archive_cryptor.c [] []
/src/libarchive/libarchive/archive_read_support_format_7zip.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_xar.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_blake2s_ref.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive_fuzzer.cc ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_zip.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_read_support_format_cpio.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_string.c ['libarchive_fuzzer'] ['libarchive_fuzzer']
/src/libarchive/libarchive/archive_ppmd8.c [] []
/src/libarchive/libarchive/archive_read_support_filter_program.c [] []

Directories in report

Directory
/src/
/usr/local/bin/../include/c++/v1/
/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-knZNIwQ0ui.data fuzzerLogFile-0-knZNIwQ0ui.data.yaml libarchive_fuzzer.covreport