1 // Copyright 2022 Code Intelligence GmbH 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package com.example; 16 17 import com.code_intelligence.jazzer.api.FuzzedDataProvider; 18 import java.util.regex.Pattern; 19 20 /** 21 * Compiling a regex pattern can lead to stack overflows and thus is caught 22 * in the constructor of {@link java.util.regex.Pattern} and rethrown as a 23 * {@link java.util.regex.PatternSyntaxException}. 24 * The {@link com.code_intelligence.jazzer.sanitizers.RegexInjection} sanitizer 25 * uses this exception to detect injections and would incorrectly report a 26 * finding. Exceptions caused by stack overflows should not be handled in the 27 * hook as it's very unlikely that the fuzzer generates a pattern causing a 28 * stack overflow before it generates an invalid one. 29 */ 30 @SuppressWarnings({"ReplaceOnLiteralHasNoEffect", "ResultOfMethodCallIgnored"}) 31 public class StackOverflowRegexInjection { fuzzerTestOneInput(FuzzedDataProvider ignored)32 public static void fuzzerTestOneInput(FuzzedDataProvider ignored) { 33 // load regex classes by using them beforehand, 34 // otherwise initialization would cause other issues. 35 Pattern.compile("\n").matcher("some string").replaceAll("\\\\n"); 36 37 generatePatternSyntaxException(); 38 } 39 40 @SuppressWarnings("InfiniteRecursion") generatePatternSyntaxException()41 private static void generatePatternSyntaxException() { 42 // try-catch on every level to not unwind the stack 43 try { 44 // generate stack overflow 45 generatePatternSyntaxException(); 46 } catch (StackOverflowError e) { 47 // invoke regex injection hook 48 "some sting".replaceAll("\n", "\\\\n"); 49 } 50 } 51 } 52