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

Table of contents

Project overview: haproxy
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: fuzz_hpack_decode
Call tree
Fuzz blockers
Runtime coverage analysis
Files reached
Fuzzer: fuzz_cfg_parser
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
fuzz_hpack_decode.c
Dictionary
Fuzzer function priority
fuzz_cfg_parser.c
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: 2026-02-02

Project overview: haproxy

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
4.0%
176 / 4573
Cyclomatic complexity statically reachable by fuzzers
1.0%
1540 / 123154
Runtime code coverage of functions
2.0%
93 / 4573

Fuzzers overview

Fuzzer Fuzzer filename Functions Reached Functions unreached Fuzzer depth Files reached Basic blocks reached Cyclomatic complexity Details
fuzz_hpack_decode fuzz_hpack_decode.c 28 2 4 8 482 175 fuzz_hpack_decode.c
fuzz_cfg_parser fuzz_cfg_parser.c 197 4514 13 30 3703 1467 fuzz_cfg_parser.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_hpack_decode

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 4 6.77%
gold [1:9] 0 0.0%
yellow [10:29] 0 0.0%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 55 93.2%
All colors 59 100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked Calltree index Parent function Callsite Largest blocked function
2 28 huff_dec call site: 00028 read_u32
1 8 hpack_idx_to_value call site: 00008 strlen
1 18 hpack_idx_to_name call site: 00018 strlen

Runtime coverage analysis

Covered functions
26
Functions that are reachable but not covered
2
Reachable functions
28
Percentage of reachable functions covered
92.86%
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_hpack_decode.c 1
include/haproxy/hpack-tbl.h 11
include/../src/hpack-dec.c 4
include/haproxy/chunk.h 2
include/import/ist.h 2
include/../src/hpack-huff.c 1
include/haproxy/net_helper.h 2
include/../src/hpack-tbl.c 3

Fuzzer: fuzz_cfg_parser

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 0 502 69.8%
gold [1:9] 16 2.22%
yellow [10:29] 29 4.03%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 172 23.9%
All colors 719 100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked Calltree index Parent function Callsite Largest blocked function
271 233 parse_cfg call site: 00233 hash_ipanon
79 56 print_message call site: 00056 ring_write
36 598 cfg_eval_cond_and call site: 00598 compare_current_version
30 537 cfg_lookup_cond_pred call site: 00537 make_arg_list
20 569 ha_warning call site: 00569 memprintf
12 173 cfg_apply_default_path call site: 00173 ha_alert
8 31 b_room call site: 00031 b_tail
7 40 generate_usermsgs_ctx_str call site: 00040 b_tail
7 705 parse_cfg call site: 00705 check_section_position
4 3 ha_alert call site: 00003 print_message_args
4 528 cfg_free_cond_term call site: 00528 chunk_destroy
3 169 cfg_apply_default_path call site: 00169 memprintf

Runtime coverage analysis

Covered functions
71
Functions that are reachable but not covered
130
Reachable functions
197
Percentage of reachable functions covered
34.01%
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_cfg_parser.c 1
src/cfgparse.c 5
src/errors.c 13
src/tools.c 37
include/haproxy/tools.h 4
include/haproxy/buf.h 20
include/haproxy/obj_type.h 2
src/ring.c 1
include/haproxy/vecpair.h 13
include/import/mt_list.h 6
include/haproxy/task.h 1
src/debug.c 3
include/haproxy/bug.h 1
src/chunk.c 1
src/task.c 1
src/clock.c 1
src/eb32tree.c 1
include/import/ebtree.h 4
src/ebtree.c 1
src/buf.c 1
include/import/xxhash.h 8
src/resolvers.c 1
include/haproxy/protocol.h 1
src/cfgcond.c 12
src/arg.c 4
include/haproxy/chunk.h 3
include/haproxy/regex.h 1
include/haproxy/intops.h 1
./src/haproxy.c 2
include/import/ist.h 5

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
read_cfg_in_discovery_mode /src/haproxy/./src/haproxy.c 2 ['int', 'N/A'] 37 0 213 49 12 1758 1 23426 21956
cfg_parse_listen /src/haproxy/src/cfgparse-listen.c 4 ['N/A', 'int', 'N/A', 'int'] 36 0 14443 1981 738 792 0 11888 2638
process_chk /src/haproxy/src/check.c 3 ['N/A', 'N/A', 'int'] 37 0 46 6 3 771 0 7917 1762
http_stats_io_handler /src/haproxy/src/stats-html.c 1 ['N/A'] 32 0 641 97 35 590 0 5427 1067
spop_io_cb /src/haproxy/src/mux_spop.c 3 ['N/A', 'N/A', 'int'] 24 0 634 125 27 440 0 3952 1035
peer_io_handler /src/haproxy/src/peers.c 1 ['N/A'] 15 0 2521 387 104 352 0 2322 973
smp_fetch_dump_all_vars /src/haproxy/src/vars.c 4 ['N/A', 'N/A', 'N/A', 'N/A'] 3 0 786 116 43 24 0 842 543

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

Functions statically reachable by fuzzers
47.0%
2128 / 4573
Cyclomatic complexity statically reachable by fuzzers
25.0%
31388 / 123154

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_hpack_decode.c

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=['huff_dec', 'hpack_idx_to_value', 'hpack_idx_to_name']

fuzz_cfg_parser.c

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=['parse_cfg', 'print_message', 'cfg_eval_cond_and', 'cfg_lookup_cond_pred', 'ha_warning', 'cfg_apply_default_path', 'b_room', 'generate_usermsgs_ctx_str', 'ha_alert']

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
cfg_eval_cond_term 100 14 14.00% ['fuzz_cfg_parser']
cfg_apply_default_path 58 14 24.13% ['fuzz_cfg_parser']

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/haproxy/include/../src/hpack-tbl.c ['fuzz_hpack_decode'] []
/src/haproxy/include/haproxy/namespace.h [] []
/src/haproxy/src/queue.c [] []
/src/haproxy/src/eb64tree.c [] []
/src/haproxy/include/haproxy/pool.h [] []
/src/haproxy/include/haproxy/sample.h [] []
/src/haproxy/src/connection.c [] []
/src/haproxy/include/haproxy/task.h ['fuzz_cfg_parser'] []
/src/haproxy/src/resolvers.c ['fuzz_cfg_parser'] []
/src/haproxy/src/eb32tree.c ['fuzz_cfg_parser'] []
/src/haproxy/src/cli.c [] []
/src/haproxy/include/haproxy/regex.h ['fuzz_cfg_parser'] []
/src/haproxy/src/channel.c [] []
/src/haproxy/src/ebsttree.c [] []
/src/haproxy/src/cache.c [] []
/src/haproxy/include/haproxy/applet.h [] []
/src/haproxy/src/task.c ['fuzz_cfg_parser'] []
/src/haproxy/src/buf.c ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/src/stream.c [] []
/src/haproxy/src/ebimtree.c [] []
/src/haproxy/fuzz_cfg_parser.c ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/include/haproxy/h1_htx.h [] []
/src/haproxy/include/../src/hpack-dec.c ['fuzz_hpack_decode'] []
/src/haproxy/include/haproxy/buf.h ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/include/import/mt_list.h ['fuzz_cfg_parser'] []
/src/haproxy/src/flt_spoe.c [] []
/src/haproxy/include/haproxy/trace.h [] []
/src/haproxy/include/import/ist.h ['fuzz_hpack_decode', 'fuzz_cfg_parser'] ['fuzz_hpack_decode', 'fuzz_cfg_parser']
/src/haproxy/src/proxy.c [] []
/src/haproxy/src/filters.c [] []
/src/haproxy/src/listener.c [] []
/src/haproxy/src/ebmbtree.c [] []
/src/haproxy/src/http_htx.c [] []
/src/haproxy/src/lb_ss.c [] []
/src/haproxy/src/vars.c [] []
/src/haproxy/src/pipe.c [] []
/src/haproxy/include/haproxy/stats.h [] []
/src/haproxy/include/haproxy/tcpcheck.h [] []
/src/haproxy/include/haproxy/chunk.h ['fuzz_hpack_decode', 'fuzz_cfg_parser'] ['fuzz_hpack_decode']
/src/haproxy/include/haproxy/limits.h [] []
/src/haproxy/src/cfgparse-listen.c [] []
/src/haproxy/include/haproxy/channel.h [] []
/src/haproxy/src/chunk.c ['fuzz_cfg_parser'] []
/src/haproxy/include/haproxy/hlua.h [] []
/src/haproxy/src/clock.c ['fuzz_cfg_parser'] []
/src/haproxy/include/haproxy/freq_ctr.h [] []
/src/haproxy/include/haproxy/vecpair.h ['fuzz_cfg_parser'] []
/src/haproxy/src/dns.c [] []
/src/haproxy/src/init.c [] []
/src/haproxy/src/regex.c [] []
/src/haproxy/src/sock_inet.c [] []
/src/haproxy/include/haproxy/port_range.h [] []
/src/haproxy/include/haproxy/sink.h [] []
/src/haproxy/include/haproxy/list.h [] []
/src/haproxy/include/haproxy/tinfo.h [] []
/src/haproxy/include/import/xxhash.h ['fuzz_cfg_parser'] []
/src/haproxy/include/haproxy/action.h [] []
/src/haproxy/include/haproxy/stream.h [] []
/src/haproxy/include/haproxy/istbuf.h [] []
/src/haproxy/src/cfgparse-global.c [] []
/src/haproxy/src/arg.c ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/include/haproxy/http-hdr.h [] []
/src/haproxy/src/errors.c ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/src/stconn.c [] []
/src/haproxy/src/mqtt.c [] []
/src/haproxy/include/haproxy/fix.h [] []
/src/haproxy/src/http.c [] []
/src/haproxy/src/lb_fwlc.c [] []
/src/haproxy/include/haproxy/cli.h [] []
/src/haproxy/include/haproxy/tools.h ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/src/mjson.c [] []
/src/haproxy/src/pool.c [] []
/src/haproxy/src/http_ext.c [] []
/src/haproxy/src/stats-proxy.c [] []
/src/haproxy/include/haproxy/spoe.h [] []
/src/haproxy/src/server_state.c [] []
/src/haproxy/src/fcgi-app.c [] []
/src/haproxy/src/lb_chash.c [] []
/src/haproxy/src/dict.c [] []
/src/haproxy/src/lb_map.c [] []
/src/haproxy/include/haproxy/bug.h ['fuzz_cfg_parser'] []
/src/haproxy/include/haproxy/check.h [] []
/src/haproxy/src/session.c [] []
/src/haproxy/src/extcheck.c [] []
/src/haproxy/src/mux_spop.c [] []
/src/haproxy/include/haproxy/server.h [] []
/src/haproxy/include/haproxy/sock.h [] []
/src/haproxy/include/haproxy/http.h [] []
/src/haproxy/include/haproxy/mux_spop-t.h [] []
/src/haproxy/src/_ceb_str.c [] []
/src/haproxy/include/haproxy/log.h [] []
/src/haproxy/src/mworker.c [] []
/src/haproxy/src/peers.c [] []
/src/haproxy/src/h1_htx.c [] []
/src/haproxy/include/haproxy/hpack-tbl.h ['fuzz_hpack_decode'] ['fuzz_hpack_decode']
/src/haproxy/src/action.c [] []
/src/haproxy/include/haproxy/htx.h [] []
/src/haproxy/include/haproxy/protocol.h ['fuzz_cfg_parser'] []
/src/haproxy/src/check.c [] []
/src/haproxy/src/limits.c [] []
/src/haproxy/src/lb_fas.c [] []
/src/haproxy/include/haproxy/session.h [] []
/src/haproxy/src/trace.c [] []
/src/haproxy/src/sink.c [] []
/src/haproxy/include/haproxy/shctx.h [] []
/src/haproxy/include/import/eb32sctree.h [] []
/src/haproxy/include/haproxy/xref.h [] []
/src/haproxy/include/haproxy/ring.h [] []
/src/haproxy/src/ebtree.c ['fuzz_cfg_parser'] []
/src/haproxy/src/freq_ctr.c [] []
/src/haproxy/include/import/eb64tree.h [] []
/src/haproxy/src/dns_ring.c [] []
/src/haproxy/src/sample.c [] []
/src/haproxy/include/haproxy/dynbuf.h [] []
/src/haproxy/src/event_hdl.c [] []
/src/haproxy/include/haproxy/vars.h [] []
/src/haproxy/src/htx.c [] []
/src/haproxy/include/haproxy/guid.h [] []
/src/haproxy/src/stick_table.c [] []
/src/haproxy/src/acl.c [] []
/src/haproxy/src/fix.c [] []
/src/haproxy/src/stats.c [] []
/src/haproxy/src/cfgparse.c ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/include/haproxy/acl.h [] []
/src/haproxy/include/haproxy/clock.h [] []
/src/haproxy/include/haproxy/mqtt.h [] []
/src/haproxy/include/import/plock.h [] []
/src/haproxy/src/sock.c [] []
/src/haproxy/include/haproxy/http_ana.h [] []
/src/haproxy/src/guid.c [] []
/src/haproxy/src/lru.c [] []
/src/haproxy/include/haproxy/proxy.h [] []
/src/haproxy/src/dgram.c [] []
/src/haproxy/src/h1.c [] []
/src/haproxy/src/slz.c [] []
/src/haproxy/src/proto_tcp.c [] []
/src/haproxy/include/haproxy/queue.h [] []
/src/haproxy/src/http_fetch.c [] []
/src/haproxy/include/haproxy/time.h [] []
/src/haproxy/src/compression.c [] []
/src/haproxy/src/http_ana.c [] []
/src/haproxy/include/haproxy/filters.h [] []
/src/haproxy/include/haproxy/thread.h [] []
/src/haproxy/include/haproxy/obj_type.h ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/src/thread.c [] []
/src/haproxy/include/haproxy/fd.h [] []
/src/haproxy/include/haproxy/connection.h [] []
/src/haproxy/src/fd.c [] []
/src/haproxy/src/cfgdiag.c [] []
/src/haproxy/src/shctx.c [] []
/src/haproxy/src/pattern.c [] []
/src/haproxy/src/tools.c ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/include/import/slz.h [] []
/src/haproxy/src/auth.c [] []
/src/haproxy/fuzz_hpack_decode.c ['fuzz_hpack_decode'] ['fuzz_hpack_decode']
/src/haproxy/include/haproxy/stconn.h [] []
/src/haproxy/src/stats-file.c [] []
/src/haproxy/src/counters.c [] []
/src/haproxy/src/log.c [] []
/src/haproxy/src/dynbuf.c [] []
/src/haproxy/include/haproxy/pattern.h [] []
/src/haproxy/src/ebistree.c [] []
/src/haproxy/include/haproxy/ticks.h [] []
/src/haproxy/src/ring.c ['fuzz_cfg_parser'] []
/src/haproxy/src/protocol.c [] []
/src/haproxy/src/backend.c [] []
/src/haproxy/src/uri_auth.c [] []
/src/haproxy/include/import/eb32tree.h [] []
/src/haproxy/include/haproxy/net_helper.h ['fuzz_hpack_decode'] ['fuzz_hpack_decode']
/src/haproxy/include/haproxy/backend.h [] []
/src/haproxy/include/haproxy/protobuf.h [] []
/src/haproxy/src/activity.c [] []
/src/haproxy/include/haproxy/signal.h [] []
/src/haproxy/src/stats-html.c [] []
/src/haproxy/src/cfgcond.c ['fuzz_cfg_parser'] ['fuzz_cfg_parser']
/src/haproxy/src/signal.c [] []
/src/haproxy/src/http_rules.c [] []
/src/haproxy/src/time.c [] []
/src/haproxy/include/haproxy/event_hdl.h [] []
/src/haproxy/include/haproxy/intops.h ['fuzz_cfg_parser'] []
/src/haproxy/src/proto_sockpair.c [] []
/src/haproxy/src/tcp_rules.c [] []
/src/haproxy/include/haproxy/activity.h [] []
/src/haproxy/src/_ceb_int.c [] []
/src/haproxy/include/haproxy/pool-os.h [] []
/src/haproxy/include/import/ebmbtree.h [] []
/src/haproxy/src/systemd.c [] []
/src/haproxy/include/haproxy/sc_strm.h [] []
/src/haproxy/src/frontend.c [] []
/src/haproxy/include/import/slz-tables.h [] []
/src/haproxy/include/haproxy/listener.h [] []
/src/haproxy/./src/haproxy.c ['fuzz_cfg_parser'] []
/src/haproxy/src/payload.c [] []
/src/haproxy/include/haproxy/h1.h [] []
/src/haproxy/src/mailers.c [] []
/src/haproxy/src/server.c [] []
/src/haproxy/src/sha1.c [] []
/src/haproxy/src/base64.c [] []
/src/haproxy/include/import/cebtree-prv.h [] []
/src/haproxy/include/import/ebtree.h ['fuzz_cfg_parser'] []
/src/haproxy/include/import/cebtree.h [] []
/src/haproxy/src/stats-json.c [] []
/src/haproxy/src/lb_fwrr.c [] []
/src/haproxy/src/hash.c [] []
/src/haproxy/src/applet.c [] []
/src/haproxy/include/../src/hpack-huff.c ['fuzz_hpack_decode'] []
/src/haproxy/include/haproxy/stick_table.h [] []
/src/haproxy/src/tcpcheck.c [] []
/src/haproxy/src/flt_http_comp.c [] []
/src/haproxy/src/proto_rhttp.c [] []
/src/haproxy/src/debug.c ['fuzz_cfg_parser'] []

Directories in report

Directory
/src/haproxy/include/../src/
/src/haproxy/include/haproxy/
/src/haproxy/include/import/
/src/haproxy/./src/
/src/haproxy/
/src/haproxy/src/

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_hpack_decode fuzzerLogFile-0-yxlclyPfQQ.data fuzzerLogFile-0-yxlclyPfQQ.data.yaml fuzz_hpack_decode.covreport
fuzz_cfg_parser fuzzerLogFile-0-os379CqejY.data fuzzerLogFile-0-os379CqejY.data.yaml fuzz_cfg_parser.covreport