Report generation date: 2025-06-30

Project overview: libwebsockets

High level conclusions

Fuzzers reach 1.938% of cyclomatic complexity.

"No files with coverage data was found. This is either because an error occurred when compiling and running coverage runs, or because the introspector run was intentionally done without coverage collection. In order to get optimal results coverage data is needed.

Reachability and coverage overview

Functions statically reachable by fuzzers

18 / 1111

Cyclomatic complexity statically reachable by fuzzers

179 / 9235

Runtime code coverage of functions

0 / 1111

Fuzzers overview

Fuzzer	Fuzzer filename	Functions Reached	Functions unreached	Fuzzer depth	Files reached	Basic blocks reached	Cyclomatic complexity	Details
lws_upng_inflate_fuzzer	/src/libwebsockets/lws_upng_inflate_fuzzer.cpp	28	1348	7	5	495	200	lws_upng_inflate_fuzzer.cpp

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: lws_upng_inflate_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 project has no code coverage. Will not display blockers as blockers depend on code coverage.

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	instr count	bb count	cyclomatic complexity	Reachable functions	total cyclomatic complexity	Unreached complexity
`rops_handle_POLLIN_h1`	/src/libwebsockets/lib/roles/h1/ops-h1.c	3	['N/A', 'N/A', 'N/A']	34	306	48	21	663	5125	5080
`lws_create_context`	/src/libwebsockets/lib/core/context.c	1	['N/A']	26	1913	211	75	545	3457	717
`lws_display_render_jpeg`	/src/libwebsockets/lib/misc/dlo/dlo-jpeg.c	1	['N/A']	9	435	49	20	71	475	410
`secstream_h2`	/src/libwebsockets/lib/secure-streams/protocols/ss-h2.c	5	['N/A', 'int', 'N/A', 'N/A', 'size_t']	27	218	34	11	380	2452	368
`lws_cache_heap_write`	/src/libwebsockets/lib/misc/cache-ttl/heap.c	6	['N/A', 'N/A', 'N/A', 'size_t', 'size_t', 'N/A']	16	334	39	14	59	281	171
`rops_perform_user_POLLOUT_h2`	/src/libwebsockets/lib/roles/h2/ops-h2.c	1	['N/A']	32	870	121	48	431	3251	167
`lws_display_render_png`	/src/libwebsockets/lib/misc/dlo/dlo-png.c	1	['N/A']	8	447	49	20	42	359	140
`lws_context_default_loop_run_destroy`	/src/libwebsockets/lib/core/libwebsockets.c	1	['N/A']	28	47	9	4	369	2122	122
`rops_handle_POLLIN_netlink`	/src/libwebsockets/lib/roles/netlink/ops-netlink.c	3	['N/A', 'N/A', 'N/A']	19	1459	160	35	306	1813	108
`lws_create_adopt_udp`	/src/libwebsockets/lib/core-net/adopt.c	10	['N/A', 'N/A', 'int', 'int', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A']	27	223	16	6	486	2940	93

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

Functions statically reachable by fuzzers

695 / 1111

Cyclomatic complexity statically reachable by fuzzers

7117 / 9235

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.

/src/libwebsockets/lws_upng_inflate_fuzzer.cpp

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Runtime coverage analysis

No runtime coverage data was found

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/libwebsockets/lib/misc/cache-ttl/lws-cache-ttl.c	[]	[]
/src/libwebsockets/lib/core/lws_dll2.c	[]	[]
/src/libwebsockets/lib/tls/openssl/openssl-session.c	[]	[]
/src/libwebsockets/lib/core-net/client/connect2.c	[]	[]
/src/libwebsockets/lib/plat/unix/unix-file.c	[]	[]
/src/libwebsockets/lib/secure-streams/system/fetch-policy/fetch-policy.c	[]	[]
/src/libwebsockets/lib/misc/sha-1.c	[]	[]
/src/libwebsockets/lib/core/libwebsockets.c	['lws_upng_inflate_fuzzer']	[]
/src/libwebsockets/lib/misc/lejp.c	[]	[]
/src/libwebsockets/lib/tls/openssl/openssl-ssl.c	[]	[]
/src/libwebsockets/lib/core-net/close.c	[]	[]
/src/libwebsockets/lib/core-net/service.c	[]	[]
/src/libwebsockets/lib/core-net/state.c	[]	[]
/src/libwebsockets/lib/core-net/client/sort-dns.c	[]	[]
/src/libwebsockets/lib/core-net/network.c	[]	[]
/src/libwebsockets/lib/system/system.c	[]	[]
/src/libwebsockets/lib/roles/raw-skt/ops-raw-skt.c	[]	[]
/src/libwebsockets/lib/roles/netlink/ops-netlink.c	[]	[]
/src/libwebsockets/lib/plat/unix/unix-misc.c	[]	[]
/src/libwebsockets/lib/tls/tls-server.c	[]	[]
/src/libwebsockets/lib/core-net/vhost.c	[]	[]
/src/libwebsockets/include/libwebsockets/lws-write.h	[]	[]
/src/libwebsockets/lib/secure-streams/protocols/ss-h1.c	[]	[]
/src/libwebsockets/lib/tls/openssl/openssl-server.c	[]	[]
/src/libwebsockets/lib/tls/tls-client.c	[]	[]
/src/libwebsockets/lib/roles/listen/ops-listen.c	[]	[]
/src/libwebsockets/lib/misc/dlo/dlo-font-mcufont.c	[]	[]
/src/libwebsockets/lib/roles/raw-file/ops-raw-file.c	[]	[]
/src/libwebsockets/lib/core-net/dummy-callback.c	[]	[]
/src/libwebsockets/lib/core-net/client/connect4.c	[]	[]
/src/libwebsockets/lib/core/vfs.c	[]	[]
/src/libwebsockets/lib/core-net/sorted-usec-list.c	[]	[]
/src/libwebsockets/lib/core-net/client/client.c	[]	[]
/src/libwebsockets/lib/misc/lwsac/lwsac.c	[]	[]
/src/libwebsockets/lib/tls/tls-sessions.c	[]	[]
/src/libwebsockets/lib/core/logs.c	['lws_upng_inflate_fuzzer']	[]
/src/libwebsockets/lib/core-net/wsi.c	[]	[]
/src/libwebsockets/lib/roles/http/date.c	[]	[]
/src/libwebsockets/lib/core-net/client/connect3.c	[]	[]
/src/libwebsockets/lib/secure-streams/protocols/ss-ws.c	[]	[]
/src/libwebsockets/lib/tls/tls.c	[]	[]
/src/libwebsockets/lib/core-net/client/conmon.c	[]	[]
/src/libwebsockets/lib/misc/base64-decode.c	[]	[]
/src/libwebsockets/lib/misc/dlo/dlo-text.c	[]	[]
/src/libwebsockets/lib/tls/lws-gencrypto-common.c	[]	[]
/src/libwebsockets/lib/plat/unix/unix-fds.c	[]	[]
/src/libwebsockets/lib/misc/dlo/dlo-png.c	[]	[]
/src/libwebsockets/lib/tls/openssl/openssl-client.c	[]	[]
/src/libwebsockets/lib/roles/http/client/client-http.c	[]	[]
/src/libwebsockets/lws_upng_inflate_fuzzer.cpp	['lws_upng_inflate_fuzzer']	[]
/src/libwebsockets/lib/roles/pipe/ops-pipe.c	[]	[]
/src/libwebsockets/lib/roles/h2/ops-h2.c	[]	[]
/src/libwebsockets/lib/plat/unix/unix-init.c	[]	[]
/src/libwebsockets/lib/roles/ws/client-parser-ws.c	[]	[]
/src/libwebsockets/lib/plat/unix/unix-caps.c	[]	[]
/src/libwebsockets/lib/secure-streams/protocols/ss-raw.c	[]	[]
/src/libwebsockets/lib/misc/cache-ttl/file.c	[]	[]
/src/libwebsockets/lib/roles/http/header.c	[]	[]
/src/libwebsockets/lib/tls/openssl/openssl-tls.c	[]	[]
/src/libwebsockets/lib/misc/upng-gzip.c	['lws_upng_inflate_fuzzer']	[]
/src/libwebsockets/lib/misc/cache-ttl/heap.c	[]	[]
/src/libwebsockets/lib/misc/dlo/dlo.c	[]	[]
/src/libwebsockets/lib/roles/h2/http2.c	[]	[]
/src/libwebsockets/lib/core-net/wsi-timeout.c	[]	[]
/src/libwebsockets/lib/secure-streams/system/auth-api.amazon.com/auth.c	[]	[]
/src/libwebsockets/lib/secure-streams/protocols/ss-h2.c	[]	[]
/src/libwebsockets/lib/event-libs/poll/poll.c	[]	[]
/src/libwebsockets/lib/tls/openssl/openssl-x509.c	[]	[]
/src/libwebsockets/lib/core/alloc.c	['lws_upng_inflate_fuzzer']	[]
/src/libwebsockets/lib/misc/upng.c	[]	[]
/src/libwebsockets/lib/core-net/adopt.c	[]	[]
/src/libwebsockets/lib/roles/ws/server-ws.c	[]	[]
/usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/limits	[]	[]
/src/libwebsockets/lib/tls/openssl/lws-genhash.c	[]	[]
/src/libwebsockets/lib/misc/dlo/dlo-jpeg.c	[]	[]
/src/libwebsockets/lib/tls/tls-network.c	[]	[]
/src/libwebsockets/lib/core/buflist.c	[]	[]
/src/libwebsockets/lib/misc/jpeg.c	[]	[]
/src/libwebsockets/lib/roles/http/server/server.c	[]	[]
/src/libwebsockets/lib/core-net/pollfd.c	[]	[]
/src/libwebsockets/lib/plat/unix/unix-service.c	[]	[]
/src/libwebsockets/lib/core-net/client/connect.c	[]	[]
/src/libwebsockets/lib/roles/http/cookie.c	[]	[]
/src/libwebsockets/include/libwebsockets/lws-dll2.h	[]	[]
/src/libwebsockets/lib/secure-streams/system/captive-portal-detect/captive-portal-detect.c	[]	[]
/src/libwebsockets/lib/core/context.c	[]	[]
/src/libwebsockets/include/libwebsockets/lws-vfs.h	[]	[]
/usr/include/openssl/x509.h	[]	[]
/src/libwebsockets/lib/roles/h1/ops-h1.c	[]	[]
/src/libwebsockets/lib/plat/unix/unix-sockets.c	[]	[]
/src/libwebsockets/lib/core-net/output.c	[]	[]
/src/libwebsockets/lib/plat/unix/unix-pipe.c	[]	[]
/src/libwebsockets/lib/secure-streams/secure-streams.c	[]	[]
/src/libwebsockets/lib/roles/ws/ops-ws.c	[]	[]
/src/libwebsockets/lib/roles/ws/client-ws.c	[]	[]
/src/libwebsockets/lib/core-net/route.c	[]	[]
/src/libwebsockets/lib/system/smd/smd.c	[]	[]
/src/libwebsockets/lib/secure-streams/policy-common.c	[]	[]
/src/libwebsockets/lib/secure-streams/policy-json.c	[]	[]
/src/libwebsockets/lib/roles/http/parsers.c	[]	[]
/src/libwebsockets/lib/roles/h2/hpack.c	[]	[]

Directories in report

Directory

/src/libwebsockets/lib/roles/netlink/
/usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/
/src/libwebsockets/lib/roles/raw-skt/
/src/libwebsockets/lib/misc/lwsac/
/src/libwebsockets/lib/misc/dlo/
/src/libwebsockets/lib/roles/h2/
/src/libwebsockets/lib/secure-streams/system/captive-portal-detect/
/src/libwebsockets/lib/core/
/src/libwebsockets/lib/plat/unix/
/src/libwebsockets/lib/roles/listen/
/src/libwebsockets/lib/roles/http/
/src/libwebsockets/lib/system/smd/
/src/libwebsockets/lib/event-libs/poll/
/src/libwebsockets/lib/secure-streams/system/auth-api.amazon.com/
/src/libwebsockets/lib/core-net/
/src/libwebsockets/lib/core-net/client/
/src/libwebsockets/lib/roles/http/client/
/src/libwebsockets/lib/roles/pipe/
/src/libwebsockets/lib/tls/
/src/libwebsockets/lib/secure-streams/protocols/
/src/libwebsockets/lib/roles/ws/
/src/libwebsockets/lib/misc/cache-ttl/
/usr/include/openssl/
/src/libwebsockets/lib/tls/openssl/
/src/libwebsockets/lib/secure-streams/system/fetch-policy/
/src/libwebsockets/include/libwebsockets/
/src/libwebsockets/lib/roles/raw-file/
/src/libwebsockets/lib/secure-streams/
/src/libwebsockets/lib/misc/
/src/libwebsockets/lib/system/
/src/libwebsockets/
/src/libwebsockets/lib/roles/h1/
/src/libwebsockets/lib/roles/http/server/

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

lws_upng_inflate_fuzzer fuzzerLogFile-0-QONvsARPC2.data fuzzerLogFile-0-QONvsARPC2.data.yaml

Table of contents