Fuzz introspector
For issues and ideas: https://github.com/ossf/fuzz-introspector/issues

Fuzzer details

Fuzzer: 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

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 2196 95.5%
gold [1:9] 2 0.08%
yellow [10:29] 0 0.0%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 101 4.39%
All colors 2299 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
2974 2974 1 :

['pr_trace_vmsg']

2974 2974 pr_trace_msg call site: 00052 /src/proftpd/src/trace.c:524
2 2 1 :

['sb_free']

2 2 parse_string call site: 02242 /src/proftpd/lib/ccan-json.c:948
2 2 1 :

['__errno_location']

2 2 pr_event_listening call site: 00056 /src/proftpd/src/event.c:284
2 2 1 :

['strncmp']

2 2 pr_event_listening call site: 00057 /src/proftpd/src/event.c:289
2 2 1 :

['__errno_location']

2 2 pcalloc call site: 00184 /src/proftpd/src/pool.c:694
2 2 1 :

['__errno_location']

2 2 alloc_pool call site: 00040 /src/proftpd/src/pool.c:652
2 2 1 :

['__errno_location']

2 2 pr_trace_msg call site: 00051 /src/proftpd/src/trace.c:516
0 5921 3 :

['pr_alarms_block', 'new_block', 'pr_alarms_unblock']

0 5921 alloc_pool call site: 00041 /src/proftpd/src/pool.c:664
0 2957 1 :

['malloc_block']

0 2957 new_block call site: 00003 /src/proftpd/src/pool.c:205
0 11 1 :

['json_delete']

0 11 json_decode call site: 02283 /src/proftpd/lib/ccan-json.c:398
0 0 None 5914 5914 smalloc call site: 00005 /src/proftpd/src/pool.c:103
0 0 None 2 2 pr_json_object_from_text call site: 02218 /src/proftpd/src/json.c:178

Runtime coverage analysis

Covered functions
56
Functions that are reachable but not covered
403
Reachable functions
459
Percentage of reachable functions covered
12.2%
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
/src/fuzzer.c 1
src/pool.c 18
src/timers.c 6
src/log.c 12
src/support.c 14
src/netaddr.c 35
src/sets.c 5
src/trace.c 6
src/event.c 3
src/table.c 31
src/signals.c 11
src/child.c 4
src/privs.c 3
lib/sstrncpy.c 1
src/configdb.c 20
lib/pr-syslog.c 4
src/pidfile.c 1
src/scoreboard.c 10
src/session.c 5
src/str.c 14
src/wtmp.c 1
src/fsio.c 27
src/inet.c 10
src/main.c 3
src/bindings.c 18
src/class.c 1
src/dirtree.c 11
src/parser.c 12
src/auth.c 10
src/stash.c 5
src/modules.c 2
src/env.c 1
src/netio.c 4
lib/pr_fnmatch.c 1
lib/./pr_fnmatch_loop.c 3
src/response.c 1
src/json.c 7
lib/ccan-json.c 31

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
ls_stat /src/proftpd/modules/mod_ls.c 1 ['struct.cmd_struc *'] 228 0 911 139 50 626 0 5348 2387
auth_pass /src/proftpd/modules/mod_auth.c 1 ['struct.cmd_struc *'] 228 0 307 44 17 592 0 4730 939
log_sess_reinit_ev /src/proftpd/modules/mod_log.c 2 ['char *', 'char *'] 228 0 88 16 6 506 2 3895 552
ctrls_postparse_ev /src/proftpd/modules/mod_ctrls.c 2 ['char *', 'char *'] 229 0 48 9 4 549 1 3689 449
xfer_stor /src/proftpd/modules/mod_xfer.c 1 ['struct.cmd_struc *'] 229 0 1199 146 55 592 0 4564 405
core_post_host /src/proftpd/modules/mod_core.c 1 ['struct.cmd_struc *'] 214 0 131 21 8 465 0 3311 290
ls_nlst /src/proftpd/modules/mod_ls.c 1 ['struct.cmd_struc *'] 230 0 1564 226 83 616 0 5119 168

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

Functions statically reachable by fuzzers
44.6%
850/1906
Cyclomatic complexity statically reachable by fuzzers
51.5%
8094 / 15715

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

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/proftpd/src/auth.c ['fuzzer'] []
/src/proftpd/src/cmd.c [] []
/src/proftpd/modules/mod_auth_unix.c [] []
/src/proftpd/src/xferlog.c [] []
/src/proftpd/src/timers.c ['fuzzer'] ['fuzzer']
/src/proftpd/src/event.c ['fuzzer'] ['fuzzer']
/src/proftpd/lib/sstrncpy.c ['fuzzer'] []
/src/proftpd/modules/mod_xfer.c [] []
/src/proftpd/src/sets.c ['fuzzer'] []
/src/proftpd/lib/ccan-json.c ['fuzzer'] ['fuzzer']
/src/proftpd/src/dirtree.c ['fuzzer'] []
/src/proftpd/src/trace.c ['fuzzer'] ['fuzzer']
/src/proftpd/modules/mod_site.c [] []
/src/proftpd/src/parser.c ['fuzzer'] []
/src/proftpd/src/main.c ['fuzzer'] []
/src/proftpd/lib/pr-syslog.c ['fuzzer'] []
/src/proftpd/src/privs.c ['fuzzer'] []
/src/proftpd/src/data.c [] []
/src/proftpd/modules/mod_ctrls.c [] []
/src/proftpd/modules/mod_facts.c [] []
/src/proftpd/src/json.c ['fuzzer'] ['fuzzer']
/src/proftpd/src/response.c ['fuzzer'] []
/src/proftpd/src/support.c ['fuzzer'] []
/src/proftpd/src/jot.c [] []
/src/proftpd/src/feat.c [] []
/src/proftpd/lib/openbsd-blowfish.c [] []
/src/proftpd/src/configdb.c ['fuzzer'] []
/src/proftpd/src/child.c ['fuzzer'] []
/src/proftpd/src/regexp.c [] []
/src/proftpd/src/bindings.c ['fuzzer'] []
/src/proftpd/src/expr.c [] []
/src/proftpd/lib/glibc-glob.c [] []
/src/proftpd/src/rlimit.c [] []
/src/proftpd/src/netaddr.c ['fuzzer'] []
/src/proftpd/src/pidfile.c ['fuzzer'] []
/src/proftpd/src/inet.c ['fuzzer'] []
/src/proftpd/src/fsio.c ['fuzzer'] []
/src/fuzzer.c ['fuzzer'] ['fuzzer']
/src/proftpd/src/error.c [] []
/src/proftpd/src/modules.c ['fuzzer'] []
/src/proftpd/src/netacl.c [] []
/src/proftpd/src/netio.c ['fuzzer'] []
/src/proftpd/src/ascii.c [] []
/src/proftpd/src/ctrls.c [] []
/src/proftpd/src/proctitle.c [] []
/src/proftpd/src/str.c ['fuzzer'] []
/src/proftpd/src/var.c [] []
/src/proftpd/src/class.c ['fuzzer'] []
/src/proftpd/src/table.c ['fuzzer'] []
/src/proftpd/modules/mod_log.c [] []
/src/proftpd/modules/mod_delay.c [] []
/src/proftpd/src/scoreboard.c ['fuzzer'] []
/src/proftpd/src/env.c ['fuzzer'] []
/src/proftpd/lib/openbsd-bcrypt.c [] []
/src/proftpd/src/wtmp.c ['fuzzer'] []
/src/proftpd/lib/pr_fnmatch.c ['fuzzer'] []
/src/proftpd/src/pool.c ['fuzzer'] ['fuzzer']
/src/proftpd/modules/mod_core.c [] []
/src/proftpd/src/stash.c ['fuzzer'] []
/src/proftpd/src/throttle.c [] []
/src/proftpd/lib/./pr_fnmatch_loop.c ['fuzzer'] []
/src/proftpd/src/display.c [] []
/src/proftpd/src/help.c [] []
/src/proftpd/src/mkhome.c [] []
/src/proftpd/modules/mod_ls.c [] []
/src/proftpd/src/log.c ['fuzzer'] ['fuzzer']
/src/proftpd/src/signals.c ['fuzzer'] []
/src/proftpd/src/session.c ['fuzzer'] []
/src/proftpd/src/filter.c [] []
/src/proftpd/modules/mod_rlimit.c [] []
/src/proftpd/lib/pwgrent.c [] []
/src/proftpd/modules/mod_auth.c [] []
/src/proftpd/src/random.c [] []
/src/proftpd/modules/mod_auth_file.c [] []

Directories in report

Directory
/src/proftpd/lib/
/src/proftpd/src/
/src/proftpd/modules/
/src/
/src/proftpd/lib/./