AdamKorcz commented on code in PR #460: URL: https://github.com/apache/logging-log4cxx/pull/460#discussion_r1930188937
########## src/fuzzers/cpp/DOMConfiguratorFuzzer.cpp: ########## @@ -0,0 +1,37 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "stdint.h" +#include <fuzzer/FuzzedDataProvider.h> +#include <log4cxx/xml/domconfigurator.h> + +using namespace log4cxx; +using namespace log4cxx::helpers; +using namespace log4cxx::xml; + +extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { + char filename[9] = "conf.xml"; + + FILE *fp = fopen(filename, "wb"); + if (!fp) { Review Comment: > For OSS-fuzz to deeply investigate the DOMConfigurator code, it would need to generate mostly valid log4cxx configuration which would be extremely unlikely, as admitted by this concluding comment in [this blog post](https://lcamtuf.blogspot.com/2014/11/pulling-jpegs-out-of-thin-air.html) > > > In practical terms, this means that afl-fuzz won't have as much luck "inventing" PNG files or non-trivial HTML documents from scratch libFuzzer will be able to explore the code because of its coverage-guided features. We can help it too by adding a seed and a dictionary which will greatly improve the fuzzers reach from the first iterations. Once the fuzzer is merged, I can add that to the OSS-Fuzz build files. > What do you expect this fuzz test to achieve? The fuzzer tests [the XML parsing of the DOM Configurator.](https://github.com/apache/logging-log4cxx/blob/da0313eb333e4f76ed7ade48075025f64f9c29e9/src/main/cpp/domconfigurator.cpp#L1056). The DOM configurator has 1000+ LoC which would be great to have fuzz coverage of. I don't see a reason to not test it. > Have you considered mimicing the fuzz test in [libexpat](https://github.com/libexpat/libexpat/tree/master/expat/fuzz)? No. Could you elaborate on the advantages of that? > Testing DOMConfigurator::configure() with an empty file should be just a unit test. The file will not be empty. The fuzzer writes the test case to the file and then invokes the DOM Configurator so that it parses it. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: notifications-unsubscr...@logging.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
