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

Table of contents

Project overview: tmux
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: input-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
fuzz/input-fuzzer.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: 2024-07-27

Project overview: tmux

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
32.0%
765 / 2388
Cyclomatic complexity statically reachable by fuzzers
32.0%
5809 / 18286
Runtime code coverage of functions
22.0%
536 / 2388

Fuzzers overview

Fuzzer Fuzzer filename Functions Reached Functions unreached Fuzzer depth Files reached Basic blocks reached Cyclomatic complexity Details
input-fuzzer fuzz/input-fuzzer.c 882 1713 37 58 15994 6047 input-fuzzer.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 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: input-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 2071 82.7%
gold [1:9] 14 0.55%
yellow [10:29] 0 0.0%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 419 16.7%
All colors 2504 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
6210 6616 10 :

['cmdq_free_state', 'options_get_string', 'cmdq_new_state', 'cmdq_add_formats', 'options_array_next', 'cmd_parse_from_string', 'free', 'options_array_first', 'notify_insert_one_hook', 'options_array_item_value']

6210 6690 notify_insert_hook call site: 01592 /src/tmux/notify.c:89
5226 5226 1 :

['control_notify_window_layout_changed']

7189 18134 notify_callback call site: 00194 /src/tmux/notify.c:131
430 430 3 :

['grid_scroll_history', 'grid_scroll_history_region', 'grid_collect_history']

430 430 grid_view_scroll_region_up call site: 00685 /src/tmux/grid-view.c:109
389 470 5 :

['osdep_get_name', 'xstrdup', 'free', 'cmd_stringify_argv', 'parse_window_name']

389 470 format_cb_current_command call site: 00000 /src/tmux/format.c:826
324 11719 10 :

['tty_write', 'log_debug', 'screen_write_set_cursor', 'grid_view_get_cell', 'screen_write_collect_flush', 'utf8_has_zwj', 'utf8_is_modifier', 'grid_view_set_cell', 'grid_view_set_padding', 'screen_write_initctx']

324 11719 screen_write_combine call site: 00717 /src/tmux/screen-write.c:2096
318 318 1 :

['screen_reflow']

318 475 screen_resize_cursor call site: 02002 /src/tmux/screen.c:315
266 266 1 :

['screen_resize_y']

584 741 screen_resize_cursor call site: 02001 /src/tmux/screen.c:308
262 262 1 :

['grid_view_clear_history']

262 279 screen_write_clearscreen call site: 00571 /src/tmux/screen-write.c:1601
218 218 1 :

['layout_dump']

218 218 format_cb_window_layout call site: 00000 /src/tmux/format.c:773
185 185 1 :

['cmd_stringify_argv']

185 185 format_cb_start_command call site: 00000 /src/tmux/format.c:799
178 178 1 :

['options_array_free']

178 188 options_array_set call site: 00000 /src/tmux/options.c:436
171 171 2 :

['cmd_find_best_winlink_with_window', 'cmd_find_log_state']

171 173 cmd_find_from_window call site: 00404 /src/tmux/cmd-find.c:775

Runtime coverage analysis

Covered functions
537
Functions that are reachable but not covered
652
Reachable functions
882
Percentage of reachable functions covered
26.08%
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/input-fuzzer.c 1
window.c 52
xmalloc.c 11
log.c 5
compat/vis.c 3
options.c 30
utf8.c 29
alerts.c 11
server-fn.c 4
notify.c 7
cmd-find.c 28
cmd-queue.c 31
format.c 57
cmd.c 23
session.c 11
control-notify.c 14
control.c 2
tmux.c 7
paste.c 3
server-client.c 8
file.c 14
proc.c 6
compat/imsg.c 9
compat/imsg-buffer.c 15
compat/recallocarray.c 1
compat/freezero.c 1
compat/getdtablecount.c 1
window-copy.c 9
screen-write.c 30
screen.c 16
tty.c 10
style.c 6
compat/strlcpy.c 1
colour.c 10
compat/strtonum.c 1
attributes.c 1
status.c 6
grid-view.c 10
grid.c 45
input.c 10
utf8-combined.c 4
compat/strlcat.c 1
hyperlinks.c 11
arguments.c 28
key-string.c 1
environ.c 14
regsub.c 3
format-draw.c 4
job.c 5
compat/getprogname.c 1
compat/fdforkpty.c 1
compat/closefrom.c 2
cmd-parse.y 29
cmd-parse.c 2
layout.c 6
tty-term.c 2
server.c 2
cfg.c 1

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
client_main /src/tmux/client.c 5 ['N/A', 'int', 'N/A', 'size_t', 'int'] 52 0 622 98 35 1383 0 10488 4603
cmd_new_session_exec /src/tmux/cmd-new-session.c 2 ['N/A', 'N/A'] 50 0 1201 203 73 1329 0 10570 1108
window_customize_init /src/tmux/window-customize.c 3 ['N/A', 'N/A', 'N/A'] 92 0 98 9 4 1019 0 7242 839
window_copy_cmd_copy_pipe_line_and_cancel /src/tmux/window-copy.c 1 ['N/A'] 92 0 16 3 2 858 0 5998 486
window_buffer_init /src/tmux/window-buffer.c 3 ['N/A', 'N/A', 'N/A'] 95 0 157 21 8 1102 0 7790 363
cmd_refresh_client_exec /src/tmux/cmd-refresh-client.c 2 ['N/A', 'N/A'] 77 0 532 83 32 921 0 6686 310
input_csi_dispatch /src/tmux/input.c 1 ['N/A'] 81 0 1140 204 40 822 0 5615 291

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

Functions statically reachable by fuzzers
68.0%
1630 / 2388
Cyclomatic complexity statically reachable by fuzzers
75.0%
13667 / 18286

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

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/input-fuzzer.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=['screen_write_cursormove', 'cmdq_next', 'notify_insert_hook', 'options_array_item', 'xrealloc', 'environ_create', 'options_array_first', 'style_parse', 'utf8_stravis', 'screen_write_start_pane']

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
colour_tostring 54 10 18.51% ['input-fuzzer']
format_entry_tree_RB_REMOVE 65 24 36.92% ['input-fuzzer']
format_entry_tree_RB_REMOVE_COLOR 74 8 10.81% ['input-fuzzer']
format_entry_tree_RB_INSERT_COLOR 42 17 40.47% ['input-fuzzer']
hyperlinks_by_inner_tree_RB_INSERT_COLOR 42 22 52.38% []
hyperlinks_by_inner_tree_RB_REMOVE 65 24 36.92% ['input-fuzzer']
hyperlinks_by_inner_tree_RB_REMOVE_COLOR 74 35 47.29% ['input-fuzzer']
options_tree_RB_REMOVE 65 18 27.69% ['input-fuzzer']
options_tree_RB_REMOVE_COLOR 74 8 10.81% ['input-fuzzer']
options_array_RB_INSERT_COLOR 42 22 52.38% []
paste_time_tree_RB_REMOVE 65 26 40.0% []
paste_time_tree_RB_REMOVE_COLOR 74 36 48.64% []
paste_time_tree_RB_INSERT_COLOR 42 21 50.0% []
windows_RB_INSERT_COLOR 42 7 16.66% ['input-fuzzer']
windows_RB_REMOVE_COLOR 74 8 10.81% ['input-fuzzer']
windows_RB_REMOVE 65 18 27.69% ['input-fuzzer']
window_pane_tree_RB_INSERT_COLOR 42 7 16.66% ['input-fuzzer']
window_pane_tree_RB_REMOVE_COLOR 74 8 10.81% ['input-fuzzer']
window_pane_tree_RB_REMOVE 65 18 27.69% ['input-fuzzer']
vis 81 24 29.62% ['input-fuzzer']
format_cb_mouse_status_range 36 5 13.88% []
format_cb_session_group_attached_list 32 9 28.12% []
notify_insert_hook 57 22 38.59% ['input-fuzzer']
options_array_set 66 18 27.27% []
screen_write_combine 59 13 22.03% ['input-fuzzer']
screen_write_overwrite 35 12 34.28% ['input-fuzzer']
screen_check_selection 72 5 6.944% ['input-fuzzer']
style_parse 170 28 16.47% ['input-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/tmux/compat/strlcat.c ['input-fuzzer'] []
/src/tmux/window-client.c [] []
/src/tmux/style.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/cmd-list-windows.c [] []
/src/tmux/cmd-confirm-before.c [] []
/src/tmux/cmd-set-option.c [] []
/src/tmux/attributes.c ['input-fuzzer'] []
/src/tmux/colour.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/file.c ['input-fuzzer'] []
/src/tmux/cmd-show-environment.c [] []
/src/tmux/cmd-attach-session.c [] []
/src/tmux/format-draw.c ['input-fuzzer'] []
/src/tmux/key-bindings.c [] []
/src/tmux/cmd.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/popup.c [] []
/src/tmux/tty-keys.c [] []
/src/tmux/compat/getdtablecount.c ['input-fuzzer'] []
/src/tmux/cmd-list-clients.c [] []
/src/tmux/cmd-bind-key.c [] []
/src/tmux/hyperlinks.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/cmd-send-keys.c [] []
/src/tmux/cmd-rotate-window.c [] []
/src/tmux/cmd-parse.y ['input-fuzzer'] []
/src/tmux/window-buffer.c [] []
/src/tmux/screen-write.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/compat/closefrom.c ['input-fuzzer'] []
/src/tmux/control-notify.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/cmd-wait-for.c [] []
/src/tmux/cmd-display-message.c [] []
/src/tmux/compat/unvis.c [] []
/src/tmux/cmd-command-prompt.c [] []
/src/tmux/cmd-source-file.c [] []
/src/tmux/tty.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/job.c ['input-fuzzer'] []
/src/tmux/control.c ['input-fuzzer'] []
/src/tmux/cmd-move-window.c [] []
/src/tmux/cmd-display-menu.c [] []
/src/tmux/cmd-show-options.c [] []
/src/tmux/input-keys.c [] []
/src/tmux/cmd-detach-client.c [] []
/src/tmux/tmux.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/cmd-join-pane.c [] []
/src/tmux/cmd-set-environment.c [] []
/src/tmux/server.c ['input-fuzzer'] []
/src/tmux/compat/vis.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/fuzz/input-fuzzer.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/cmd-rename-window.c [] []
/src/tmux/cmd-queue.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/cmd-pipe-pane.c [] []
/src/tmux/cmd-parse.c ['input-fuzzer'] []
/src/tmux/format.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/window.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/cmd-paste-buffer.c [] []
/src/tmux/cmd-resize-pane.c [] []
/src/tmux/server-client.c ['input-fuzzer'] []
/src/tmux/status.c ['input-fuzzer'] []
/src/tmux/cmd-split-window.c [] []
/src/tmux/server-fn.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/screen.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/cmd-capture-pane.c [] []
/src/tmux/cmd-list-sessions.c [] []
/src/tmux/paste.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/mode-tree.c [] []
/src/tmux/cmd-choose-tree.c [] []
/src/tmux/cmd-kill-server.c [] []
/src/tmux/cmd-new-window.c [] []
/src/tmux/cmd-new-session.c [] []
/src/tmux/cmd-select-layout.c [] []
/src/tmux/session.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/window-copy.c ['input-fuzzer'] []
/src/tmux/compat/setproctitle.c [] []
/src/tmux/compat/imsg-buffer.c ['input-fuzzer'] []
/src/tmux/cmd-select-pane.c [] []
/src/tmux/cmd-lock-server.c [] []
/src/tmux/cmd-server-access.c [] []
/src/tmux/cmd-if-shell.c [] []
/src/tmux/compat/getpeereid.c [] []
/src/tmux/cmd-switch-client.c [] []
/src/tmux/tty-features.c [] []
/src/tmux/cmd-kill-session.c [] []
/src/tmux/cmd-save-buffer.c [] []
/src/tmux/utf8-combined.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/log.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/layout.c ['input-fuzzer'] []
/src/tmux/cmd-refresh-client.c [] []
/src/tmux/cmd-respawn-pane.c [] []
/src/tmux/cmd-find.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/compat/getopt.c [] []
/src/tmux/names.c [] []
/src/tmux/spawn.c [] []
/src/tmux/utf8.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/compat/freezero.c ['input-fuzzer'] []
/src/tmux/cmd-kill-window.c [] []
/src/tmux/cmd-run-shell.c [] []
/src/tmux/compat/fgetln.c [] []
/src/tmux/cmd-show-prompt-history.c [] []
/src/tmux/cmd-kill-pane.c [] []
/src/tmux/proc.c ['input-fuzzer'] []
/src/tmux/compat/htonll.c [] []
/src/tmux/cmd-swap-window.c [] []
/src/tmux/compat/strtonum.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/compat/fdforkpty.c ['input-fuzzer'] []
/src/tmux/cmd-list-keys.c [] []
/src/tmux/cmd-show-messages.c [] []
/src/tmux/compat/recallocarray.c ['input-fuzzer'] []
/src/tmux/input.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/osdep-linux.c [] []
/src/tmux/cmd-list-buffers.c [] []
/src/tmux/cmd-rename-session.c [] []
/src/tmux/cmd-unbind-key.c [] []
/src/tmux/notify.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/regsub.c ['input-fuzzer'] []
/src/tmux/server-acl.c [] []
/src/tmux/client.c [] []
/src/tmux/grid-reader.c [] []
/src/tmux/cmd-swap-pane.c [] []
/src/tmux/compat/getprogname.c ['input-fuzzer'] []
/src/tmux/menu.c [] []
/src/tmux/cmd-display-panes.c [] []
/src/tmux/tty-acs.c [] []
/src/tmux/environ.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/cmd-set-buffer.c [] []
/src/tmux/compat/imsg.c ['input-fuzzer'] []
/src/tmux/tty-term.c ['input-fuzzer'] []
/src/tmux/grid-view.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/arguments.c ['input-fuzzer'] []
/src/tmux/cmd-copy-mode.c [] []
/src/tmux/window-tree.c [] []
/src/tmux/grid.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/compat/ntohll.c [] []
/src/tmux/cmd-break-pane.c [] []
/src/tmux/alerts.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/xmalloc.c ['input-fuzzer'] ['input-fuzzer']
/src/tmux/resize.c [] []
/src/tmux/compat/strlcpy.c ['input-fuzzer'] []
/src/tmux/cmd-find-window.c [] []
/src/tmux/key-string.c ['input-fuzzer'] []
/src/tmux/cmd-list-panes.c [] []
/src/tmux/cmd-select-window.c [] []
/src/tmux/screen-redraw.c [] []
/src/tmux/cmd-resize-window.c [] []
/src/tmux/layout-custom.c [] []
/src/tmux/cmd-respawn-window.c [] []
/src/tmux/window-clock.c [] []
/src/tmux/cmd-load-buffer.c [] []
/src/tmux/layout-set.c [] []
/src/tmux/window-customize.c [] []
/src/tmux/cfg.c ['input-fuzzer'] []
/src/tmux/options.c ['input-fuzzer'] ['input-fuzzer']

Directories in report

Directory
/src/tmux/
/src/tmux/fuzz/
/src/tmux/compat/

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
input-fuzzer fuzzerLogFile-0-OgI6oVnFDh.data fuzzerLogFile-0-OgI6oVnFDh.data.yaml input-fuzzer.covreport