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

Table of contents

Project overview: jupyter_server
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: fuzz_serialization
Call tree
Fuzz blockers
Runtime coverage analysis
Files reached
Analyses and suggestions
Optimal target analysis
Remaining optimal interesting functions
All functions overview
Runtime coverage analysis
Complex functions with low coverage
Files and Directories in report
Files in report
Directories in report
Metadata section
Function call coverage
Function in each files in report
Report generation date: 2023-04-10

Project overview: jupyter_server

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
1.0%
17 / 1371
Cyclomatic complexity statically reachable by fuzzers
1.0%
60 / 4593
Runtime code coverage of functions
27.0%
374 / 1371

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
fuzz_serialization /src/fuzz_serialization.py 71 2662 6 5 28 219 fuzz_serialization.py

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: fuzz_serialization

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 67 45.5%
gold [1:9] 0 0.0%
yellow [10:29] 0 0.0%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 80 54.4%
All colors 147 100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked Calltree index Parent function Callsite Largest blocked function
35 25 jupyter_client.session.json_packer call site: 00025 jupyter_client.jsonutil.json_clean
13 11 jupyter_client.session.Session._check_packers call site: 00011 jupyter_client.session.Session._check_packers.
6 106 jupyter_client.session.Session.msg call site: 00106 fdp.ConsumeBytes
4 66 jupyter_client.session.Session._check_packers call site: 00066 jupyter_client.session.Session._check_packers.
3 142 jupyter_client.jsonutil.parse_date call site: 00142 warnings.warn
2 97 jupyter_client.session.Session._new_auth call site: 00097 traitlets.log.get_logger
2 103 jupyter_client.session.Session.msg call site: 00103 .isinstance
1 73 jupyter_client.session.json_unpacker call site: 00073 pickle.loads
1 136 jupyter_client.jsonutil.extract_dates call site: 00136 jupyter_client.jsonutil.extract_dates

Runtime coverage analysis

Covered functions
181
Functions that are reachable but not covered
56
Reachable functions
71
Percentage of reachable functions covered
21.13%
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
/ 1
...fuzz_serialization 9
jupyter_client.session 29
jupyter_client.jsonutil 30
jupyter_server.services.kernels.connection.base 13

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
jupyter_server.serverapp.ServerApp.initialize jupyter_server.serverapp 5 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 3 0 18 5 5 143 0 462 438
jupyter_server.auth.decorator.authorized.wrapper.inner jupyter_server.auth.decorator 3 ['N/A', 'N/A', 'N/A'] 3 0 1 5 5 135 1 436 378
jupyter_server.services.contents.filemanager.AsyncFileContentsManager.copy jupyter_server.services.contents.filemanager 3 ['N/A', 'N/A', 'N/A'] 5 0 2 5 5 124 1 403 340
jupyter_client.manager.KernelManager._async_restart_kernel jupyter_client.manager 4 ['N/A', 'N/A', 'N/A', 'N/A'] 4 0 5 2 4 63 0 206 170
jupyter_client.localinterfaces._load_ips jupyter_client.localinterfaces 1 ['N/A'] 2 0 3 2 4 41 2 132 117
jupyter_server.auth.identity.IdentityProvider._get_user jupyter_server.auth.identity 2 ['N/A', 'N/A'] 2 0 5 8 6 41 1 133 100
jupyter_server.auth.login.LegacyLoginHandler.post jupyter_server.auth.login 1 ['N/A'] 2 0 7 4 5 53 0 167 95

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

Functions statically reachable by fuzzers
17.0%
229 / 1371
Cyclomatic complexity statically reachable by fuzzers
18.0%
811 / 4593

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

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
jupyter_client.session.Session.send 40 0 0.0% []
jupyter_client.session.Session.deserialize 41 0 0.0% []
jupyter_client.jsonutil.json_clean 31 0 0.0% ['fuzz_serialization']
os.walk 90 30 33.33% []
traitlets.config.catch_config_error 1579 350 22.16% []
loop.spawn_callback 278 99 35.61% []
traitlets.config.configurable.LoggingConfigurable._kernel_ports.pop 245 81 33.06% []
stream.on_recv 760 116 15.26% []
typing.cast.cancel 448 232 51.78% []
future.set_exception 391 80 20.46% []
adapters.get 41 17 41.46% []
asyncio.Lock 92 44 47.82% []
jupyter_client.client.KernelClient._async_execute_interactive 53 0 0.0% []
jupyter_client.connect.write_connection_file 54 0 0.0% []
tornado.concurrent.Future 81 38 46.91% []
paths.items 441 53 12.01% []
jupyter_client.launcher.launch_kernel 54 1 1.851% []
platform.system 130 34 26.15% []
tornado.httpserver.HTTPServer 127 44 34.64% []
tornado.log.app_log.exception 115 27 23.47% []
tornado.escape.utf8 146 53 36.30% []
tornado.httputil.url_concat 434 114 26.26% []
tornado.web.RequestHandler.application.last_activity 1414 308 21.78% []
traitlets.config.application.Application.launch_instance 499 137 27.45% []
tornado.netutil.Resolver.__init__ 233 65 27.89% []
template.render 494 108 21.86% []
tornado.gen.with_timeout 322 78 24.22% []
inspect.iscoroutinefunction 537 7 1.303% []
tornado.httpclient.AsyncHTTPClient.fetch 245 70 28.57% []
connection.disconnect 429 60 13.98% []
zmq.eventloop.zmqstream.ZMQStream 285 74 25.96% []
tornado.websocket.websocket_connect 741 161 21.72% []
parser.parse_args 816 376 46.07% []

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
[] []
[] []
tempfile [] []
importlib_metadata [] []
jupyter_client.utils [] []
websocket [] []
pickle [] []
traceback [] []
jupyter_server.base.websocket [] []
weakref [] []
logging [] []
jupyter_server.services.kernels.handlers [] []
getpass [] []
jupyter_client.provisioning.provisioner_base [] []
notebook [] []
time [] []
stat [] []
jupyter_server.services.kernelspecs [] []
jupyter_server.services.kernelspecs.handlers [] []
jupyter_client.channelsabc [] []
jupyter_server.view.handlers [] []
argparse [] []
jupyter_server.view [] []
jupyter_server.gateway.managers [] []
jupyter_client.kernelspec [] []
jupyter_client.ssh.tunnel [] []
jupyter_server.log [] []
tornado [] []
jupyter_server.terminal.handlers [] []
importlib [] []
jupyter_server.nbconvert.handlers [] []
hashlib [] []
jupyter_client.connect [] []
datetime [] []
jupyter_server.services.kernels.connection [] []
jupyter_server.extension [] []
jupyter_server.services.kernels.websocket [] []
jupyter_server.services.config.handlers [] []
jupyter_core [] []
ipykernel [] []
jupyter_server.base.handlers [] []
jupyter_client.kernelspecapp [] []
os [] []
pprint [] []
_subprocess [] []
jupyter_server.services.contents.largefilemanager [] []
jupyter_events [] []
jupyter_server.services.api [] []
jupyter_client.blocking [] []
jupyter_server.services.shutdown [] []
jinja2 [] []
copy [] []
jupyter_server.services.contents.manager [] []
queue [] []
asyncio [] []
signal [] []
platform [] []
shutil [] []
jupyter_server.services.kernels.connection.channels [] []
typing [] []
jupyter_server.services.config [] []
select [] []
jupyter_client.runapp [] []
ipaddress [] []
jupyter_client.ssh.forward [] []
jupyter_client.kernelapp [] []
jupyter_server.utils [] []
jupyter_client.jsonutil ['fuzz_serialization'] []
jupyter_server.traittypes [] []
jupyter_client [] []
jupyter_server.services.contents.handlers [] []
jupyter_server.nbconvert [] []
functools [] []
jupyter_client.launcher [] []
pathlib [] []
jupyter_server.services.api.handlers [] []
jupyter_client.consoleapp [] []
packaging [] []
nbconvert [] []
traitlets [] []
IPython [] []
jupyter_client.channels [] []
jupyter_server.kernelspecs.handlers [] []
warnings [] []
atheris [] []
argon2 [] []
jupyter_client.session ['fuzz_serialization'] []
zipfile [] []
jupyter_server._tz [] []
_winapi [] []
jupyter_server.auth.logout [] []
jupyter_server.extension.manager [] []
sys [] []
socketserver [] []
jupyter_server.services.sessions [] []
subprocess [] []
send2trash [] []
jupyter_server.files [] []
jupyter_server.transutils [] []
jupyter_client.asynchronous [] []
jupyter_client.provisioning [] []
jupyter_server.services.sessions.handlers [] []
zmq [] []
ctypes [] []
jupyter_client.client [] []
jupyter_server.auth.decorator [] []
jupyter_server.extension.config [] []
jupyter_server.terminal [] []
jupyter_server.base [] []
prometheus_client [] []
jupyter_server.services.contents [] []
jupyter_client.manager [] []
find_connection_file [] []
jupyter_client.ioloop.restarter [] []
types [] []
jupyter_server.auth.identity [] []
netifaces [] []
jupyter_server.services.kernels.connection.base ['fuzz_serialization'] []
jupyter_server.auth [] []
jupyter_server.services.sessions.sessionmanager [] []
hmac [] []
pexpect [] []
jupyter_server.services.config.manager [] []
jupyter_server.prometheus [] []
jupyter_server.services.contents.checkpoints [] []
jupyter_server.__main__ [] []
jupyter_server [] []
jupyter_server.services.nbconvert.handlers [] []
jupyter_server.base.zmqhandlers [] []
jupyter_server.pytest_plugin [] []
jupyter_client.provisioning.local_provisioner [] []
jupyter_server._version [] []
jupyter_server._sysinfo [] []
jupyter_server.auth.utils [] []
jupyter_server.services.kernels.kernelmanager [] []
jupyter_server.gateway.handlers [] []
jupyter_server.extension.serverextension [] []
jupyter_client.multikernelmanager [] []
jupyter_client.managerabc [] []
binascii [] []
anyio [] []
jupyter_server.services.contents.filecheckpoints [] []
gettext [] []
jupyter_server.extension.handler [] []
jupyter_server.services [] []
inspect [] []
jupyter_server.extension.application [] []
fnmatch [] []
jupyter_server.services.events [] []
re [] []
struct [] []
jupyter_server.services.contents.fileio [] []
http [] []
urllib [] []
io [] []
socket [] []
jupyter_server.services.kernels.connection.abc [] []
itertools [] []
jupyter_server.services.kernels [] []
jupyter_server.services.contents.filemanager [] []
jupyter_client.provisioning.factory [] []
jupyter_client.clientabc [] []
...fuzz_serialization ['fuzz_serialization'] []
jupyter_server.i18n [] []
jupyter_server.services.events.handlers [] []
json [] []
jupyter_client.adapter [] []
jupyter_server.prometheus.log_functions [] []
pysqlite2 [] []
email [] []
jupyter_server.services.security [] []
jupyter_client.ioloop [] []
glob [] []
nbformat [] []
jupyter_server.auth.security [] []
jupyter_client.asynchronous.client [] []
concurrent [] []
ast [] []
jupyter_client.restarter [] []
jupyter_server.auth.authorizer [] []
jupyter_server.gateway [] []
random [] []
uuid [] []
jupyter_server.kernelspecs [] []
jupyter_server.services.nbconvert [] []
jupyter_server.config_manager [] []
jupyter_server.services.security.handlers [] []
threading [] []
collections [] []
abc [] []
dateutil [] []
sqlite3 [] []
jupyter_server.serverapp [] []
jupyter_client.ssh [] []
jupyter_server.auth.login [] []
jupyter_server.files.handlers [] []
jupyter_server.terminal.terminalmanager [] []
jupyter_server.auth.__main__ [] []
jupyter_server.terminal.api_handlers [] []
jupyter_client.blocking.client [] []
jupyter_client.threaded [] []
jupyter_client.win_interrupt [] []
webbrowser [] []
jupyter_client._version [] []
jupyter_server.prometheus.metrics [] []
math [] []
jupyter_server.gateway.gateway_client [] []
jupyter_client.localinterfaces [] []
jupyter_server.extension.utils [] []
resource [] []
jupyter_client.ioloop.manager [] []
atexit [] []
dataclasses [] []
tunnel_to_kernel [] []
mimetypes [] []
paramiko [] []
textwrap [] []
base64 [] []
multiprocessing [] []

Directories in report

Directory

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_serialization fuzzerLogFile-fuzz_serialization.data fuzzerLogFile-fuzz_serialization.data.yaml all_cov.json