examples/java/com/example/NativeUbsanFuncPtrFuzzTest.cpp

// Copyright 2021 Google LLC
//
// 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
//
//    https://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.

// parse calls a function through a pointer of a mismatched type. This is
// detected by UBSAN's function check.

#include "NativeUbsanFuncPtrFuzzTest.h"

#include <cstddef>
#include <cstdint>

int parse_data(const uint16_t *data) {
  return data[0] + data[1];
}

int (*mistyped_function_pointer)(const char *data);

JNIEXPORT int JNICALL Java_com_example_NativeUbsanFuncPtrFuzzTest_parse(
    JNIEnv *env, jobject o, jstring bytes) {
  const char *input(env->GetStringUTFChars(bytes, nullptr));
  mistyped_function_pointer =
      reinterpret_cast<int (*)(const char *)>(&parse_data);
  int result = mistyped_function_pointer(input);
  env->ReleaseStringUTFChars(bytes, input);
  return result;
}