This is a small project for fuzzing Apache Commons CSV with the jazzer fuzzing tool.
See Fuzzing for a general description of the theory behind fuzzy testing.
Because Java uses a runtime environment which does not crash on invalid actions of an
application (unless native code is invoked), Fuzzing of Java-based applications
focuses on the following:
- verify if only expected exceptions are thrown
- verify any JNI or native code calls
- find cases of unbounded memory allocations
Apache Commons CSV does not use JNI or native code, so the fuzzing target tries to trigger unexpected exceptions and unbounded memory allocations.
Build the fuzzing target:
./gradlew shadowJar
Copy over the corpus of test-files from Apache Commons Compress sources
cp -a /opt/commons-csv/src/test/resources corpus/
Create a directory for the "complex" fuzzing
mkdir -p corpusComplex
You can add documents from other testing-corpora as well. Valid documents as well as slightly broken ones are good sources as this helps the fuzzer to come up with interesting new cases.
Download Jazzer from the releases page,
choose the latest version and select the file jazzer-<os>-<version>.tar.gz
Unpack the archive:
tar xzf jazzer-*.tar.gz
Invoke the fuzzing:
With only fuzzing the CSV input file based on input files:
./jazzer --cp=build/libs/csv-fuzz-all.jar --instrumentation_includes=org.apache.commons.** --target_class=org.dstadler.csv.fuzz.Fuzz -rss_limit_mb=4096 corpus
When also fuzzing the CSV format via "complex" fuzzing (cannot use an external corpus):
./jazzer --cp=build/libs/csv-fuzz-all.jar --instrumentation_includes=org.apache.commons.** --target_class=org.dstadler.csv.fuzz.FuzzComplex -rss_limit_mb=4096 corpusComplex
In this mode Jazzer will stop whenever it detects an unexpected exception or crashes.
You can use --keep_going=10 to report a given number of exceptions before stopping.
See ./jazzer for options which can control details of how Jazzer operates.
Copyright 2023 Dominik Stadler
Licensed 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.