High level conclusions

Fuzzers reach 54.79% of cyclomatic complexity.

Fuzzers reach 51.20% of all functions.

Fuzzer db-daemon_fuzzer is blocked:

The runtime code coverage of db-daemon_fuzzer covers 12.5% of its statically reachable code. This means there is some place that blocks the fuzzer to continue exploring more code at run time.

Reachability and coverage overview

Functions statically reachable by fuzzers

85 / 166

Cyclomatic complexity statically reachable by fuzzers

543 / 991

Runtime code coverage of functions

46 / 166

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: qrexec_remote_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	27	50.0%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	27	50.0%
All colors	54	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
4	131	7 : View List ['do_replace_chars', 'read_vchan_all', 'fuzz_libvchan_recv', 'fuzz_libvchan_data_ready', 'write_stdin', 'write_all', '__errno_location']	4	131	handle_remote_data	call site: 00048	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/remote.c:123
0	0	None	24	39	flush_client_data	call site: 00011	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/write-stdin.c:43
0	0	None	23	23	write_stdin	call site: 00043	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/write-stdin.c:80
0	0	None	21	21	write_stdin	call site: 00036	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/write-stdin.c:70
0	0	None	4	131	handle_remote_data	call site: 00010	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/remote.c:57
0	0	None	4	131	handle_remote_data	call site: 00032	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/remote.c:84
0	0	None	4	131	handle_remote_data	call site: 00032	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/remote.c:91
0	0	None	4	131	handle_remote_data	call site: 00046	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/remote.c:109
0	0	None	4	131	handle_remote_data	call site: 00048	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/remote.c:117
0	0	None	4	4	write_stdin	call site: 00042	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/write-stdin.c:76
0	0	None	2	15	write_all	call site: 00050	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/ioall.c:62
0	0	None	0	6	fuzz_libvchan_read	call site: 00028	/src/qubes-os/qubes-core-qrexec/fuzz/fuzz.c:62

Runtime coverage analysis

Covered functions

18

Functions that are reachable but not covered

12

Reachable functions

30

Percentage of reachable functions covered

60.0%

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
qubes-core-qrexec/fuzz/qrexec_remote_fuzzer.c	2
qubes-core-qrexec/fuzz/fuzz.c	9
qubes-core-qrexec/fuzz/../libqrexec/buffer.c	8
qubes-core-qrexec/fuzz/../libqrexec/remote.c	1
qubes-core-qrexec/fuzz/../libqrexec/libqrexec-utils.h	1
qubes-core-qrexec/fuzz/../libqrexec/write-stdin.c	2
qubes-core-qrexec/fuzz/../libqrexec/txrx-vchan.c	1
qubes-core-qrexec/fuzz/../libqrexec/replace.c	1
qubes-core-qrexec/fuzz/../libqrexec/ioall.c	1

Fuzzer: input-proxy-receiver_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	38	35.5%
gold	[1:9]	34	31.7%
yellow	[10:29]	1	0.93%
greenyellow	[30:49]	1	0.93%
lawngreen	50+	33	30.8%
All colors	107	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
2	2	1 : View List ['perror']	2	2	validate_and_forward_event	call site: 00086	/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c:321
0	0	None	2	2	receive_and_validate_caps	call site: 00061	/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c:76
0	0	None	2	2	receive_and_validate_caps	call site: 00065	/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c:96
0	0	None	2	2	receive_and_validate_caps	call site: 00068	/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c:113
0	0	None	0	0	long_set_bit	call site: 00012	/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c:52
0	0	None	0	0	receive_and_validate_caps	call site: 00063	/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c:82
0	0	None	0	0	receive_and_validate_caps	call site: 00080	/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c:153
0	0	None	0	0	input_proxy_receiver_main	call site: 00011	/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c:581

Runtime coverage analysis

Covered functions

11

Functions that are reachable but not covered

12

Reachable functions

23

Percentage of reachable functions covered

47.83%

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
app-linux-input-proxy/fuzz/input-proxy-receiver_fuzzer.c	1
app-linux-input-proxy/fuzz/../src/common.c	2
app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c	9

Fuzzer: qubesrpc_parse_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	6	27.2%
gold	[1:9]	0	0.0%
yellow	[10:29]	3	13.6%
greenyellow	[30:49]	3	13.6%
lawngreen	50+	10	45.4%
All colors	22	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
0	0	None	22	28	parse_qubes_rpc_command	call site: 00001	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/exec.c:312
0	0	None	18	24	parse_qubes_rpc_command	call site: 00001	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/exec.c:320
0	0	None	18	24	parse_qubes_rpc_command	call site: 00003	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/exec.c:327
0	0	None	10	16	parse_qubes_rpc_command	call site: 00007	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/exec.c:362
0	0	None	4	10	parse_qubes_rpc_command	call site: 00009	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/exec.c:381
0	0	None	0	6	parse_qubes_rpc_command	call site: 00006	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/exec.c:355
0	0	None	0	0	parse_qubes_rpc_command	call site: 00012	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/exec.c:398

Runtime coverage analysis

Covered functions

3

Functions that are reachable but not covered

7

Reachable functions

10

Percentage of reachable functions covered

30.0%

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
qubes-core-qrexec/fuzz/qubesrpc_parse_fuzzer.c	1
qubes-core-qrexec/fuzz/../libqrexec/exec.c	2

Fuzzer: db-daemon_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	115	92.7%
gold	[1:9]	0	0.0%
yellow	[10:29]	8	6.45%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	1	0.80%
All colors	124	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
25	25	3 : View List ['perror', 'libvchan_recv', 'verify_hdr']	504	508	handle_vchan_data	call site: 00026	/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/db-cmds.c:687
0	0	None	2	2	qubesdb_init	call site: 00001	/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/db-core.c:20
0	0	None	2	2	qubesdb_init	call site: 00001	/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/db-core.c:25
0	0	None	0	0	handle_vchan_data	call site: 00035	/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/db-cmds.c:710

Runtime coverage analysis

Covered functions

6

Functions that are reachable but not covered

42

Reachable functions

48

Percentage of reachable functions covered

12.5%

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
qubes-core-qubesdb/fuzz/db-daemon_fuzzer.c	6
qubes-core-qubesdb/fuzz/../daemon/db-core.c	6
qubes-core-qubesdb/fuzz/../daemon/db-cmds.c	14
qubes-core-qubesdb/fuzz/../daemon/buffer.c	4
qubes-core-qubesdb/fuzz/../daemon/buffer.h	1

Fuzzer: qrexec_daemon_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	120	70.1%
gold	[1:9]	7	4.09%
yellow	[10:29]	3	1.75%
greenyellow	[30:49]	4	2.33%
lawngreen	50+	37	21.6%
All colors	171	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
0	21	1 : View List ['send_service_refused']	0	21	handle_execute_service	call site: 00039	/src/qubes-os/qubes-core-qrexec/fuzz/../daemon/qrexec-daemon.c:1043
0	4	1 : View List ['fuzz_exit']	0	4	send_service_refused	call site: 00036	/src/qubes-os/qubes-core-qrexec/fuzz/../daemon/qrexec-daemon.c:712
0	0	None	2	276	handle_message_from_agent	call site: 00038	/src/qubes-os/qubes-core-qrexec/fuzz/../daemon/qrexec-daemon.c:1313
0	0	None	0	6	fuzz_libvchan_read	call site: 00009	/src/qubes-os/qubes-core-qrexec/fuzz/fuzz.c:62
0	0	None	0	4	send_service_refused	call site: 00032	/src/qubes-os/qubes-core-qrexec/fuzz/../daemon/qrexec-daemon.c:707
0	0	None	0	0	fuzz_libvchan_read	call site: 00010	/src/qubes-os/qubes-core-qrexec/fuzz/fuzz.c:65
0	0	None	0	0	fuzz_write	call site: 00033	/src/qubes-os/qubes-core-qrexec/fuzz/fuzz.c:128
0	0	None	0	0	fuzz_write	call site: 00034	/src/qubes-os/qubes-core-qrexec/fuzz/fuzz.c:131

Runtime coverage analysis

Covered functions

21

Functions that are reachable but not covered

36

Reachable functions

57

Percentage of reachable functions covered

36.84%

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
qubes-core-qrexec/fuzz/qrexec_daemon_fuzzer.c	2
qubes-core-qrexec/fuzz/fuzz.c	10
qubes-core-qrexec/fuzz/../daemon/qrexec-daemon.c	14
qubes-core-qrexec/fuzz/../libqrexec/ioall.c	3

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
fuzz_main	/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/db-daemon.c	2	['int', 'char **']	8	0	304	48	7	102	0	407	181
execute_qubes_rpc_command	/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/exec.c	7	['char *', 'int *', 'int *', 'int *', 'int *', 'bool', 'struct.buffer *']	5	0	89	9	4	46	0	174	67
init	/src/qubes-os/qubes-core-qrexec/fuzz/../daemon/qrexec-daemon.c	1	['int']	5	0	363	69	9	48	0	126	58
handle_message_from_client	/src/qubes-os/qubes-core-qrexec/fuzz/../daemon/qrexec-daemon.c	1	['int']	6	0	62	12	13	26	0	119	51
register_device	/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c	2	['struct.options *', 'int']	2	0	599	88	34	13	0	70	46

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

Functions statically reachable by fuzzers

135 / 166

Cyclomatic complexity statically reachable by fuzzers

862 / 991

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

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
validate_and_forward_event	104	24	23.07%	['input-proxy-receiver_fuzzer']
handle_vchan_data	73	15	20.54%	['db-daemon_fuzzer']
handle_execute_service	111	13	11.71%	['qrexec_daemon_fuzzer']

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/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/unix-server.c	[]	[]
/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/buffer.c	['db-daemon_fuzzer']	[]
/src/qubes-os/qubes-core-qrexec/fuzz/qrexec_daemon_fuzzer.c	['qrexec_daemon_fuzzer']	['qrexec_daemon_fuzzer']
/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/db-cmds.c	['db-daemon_fuzzer']	[]
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/replace.c	['qrexec_remote_fuzzer']	[]
/src/qubes-os/qubes-core-qrexec/fuzz/qrexec_remote_fuzzer.c	['qrexec_remote_fuzzer']	['qrexec_remote_fuzzer']
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/txrx-vchan.c	['qrexec_remote_fuzzer']	[]
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/log.c	[]	[]
/src/qubes-os/qubes-core-qrexec/fuzz/../daemon/qrexec-daemon.c	['qrexec_daemon_fuzzer']	[]
/src/qubes-os/app-linux-input-proxy/fuzz/input-proxy-receiver_fuzzer.c	['input-proxy-receiver_fuzzer']	['input-proxy-receiver_fuzzer']
/src/qubes-os/app-linux-input-proxy/fuzz/../src/input-proxy-receiver.c	['input-proxy-receiver_fuzzer']	[]
/src/qubes-os/qubes-core-qrexec/fuzz/qubesrpc_parse_fuzzer.c	['qubesrpc_parse_fuzzer']	['qubesrpc_parse_fuzzer']
/src/qubes-os/qubes-core-qrexec/fuzz/fuzz.c	['qrexec_remote_fuzzer', 'qrexec_daemon_fuzzer']	['qrexec_remote_fuzzer', 'qrexec_daemon_fuzzer']
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/remote.c	['qrexec_remote_fuzzer']	[]
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/exec.c	['qubesrpc_parse_fuzzer']	[]
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/ioall.c	['qrexec_remote_fuzzer', 'qrexec_daemon_fuzzer']	[]
/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/db-daemon.c	[]	[]
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/write-stdin.c	['qrexec_remote_fuzzer']	[]
/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/db-core.c	['db-daemon_fuzzer']	[]
/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/buffer.h	['db-daemon_fuzzer']	[]
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/libqrexec-utils.h	['qrexec_remote_fuzzer']	[]
/src/qubes-os/qubes-core-qubesdb/fuzz/db-daemon_fuzzer.c	['db-daemon_fuzzer']	['db-daemon_fuzzer']
/src/qubes-os/app-linux-input-proxy/fuzz/../src/common.c	['input-proxy-receiver_fuzzer']	[]
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/buffer.c	['qrexec_remote_fuzzer']	[]

Directories in report

Directory
/src/qubes-os/qubes-core-qrexec/fuzz/../libqrexec/
/src/qubes-os/app-linux-input-proxy/fuzz/
/src/qubes-os/qubes-core-qubesdb/fuzz/
/src/qubes-os/qubes-core-qrexec/fuzz/
/src/qubes-os/qubes-core-qubesdb/fuzz/../daemon/
/src/qubes-os/app-linux-input-proxy/fuzz/../src/
/src/qubes-os/qubes-core-qrexec/fuzz/../daemon/