examples/ubsan_int_overflow_fuzz_test.cc

// Copyright 2020 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.

// A fuzz target that triggers a signed integer overflow, which is undefined
// behavior and detected by UBSAN's signed-integer-overflow check.

#include <cstddef>
#include <cstdint>

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
  if (size == 0) {
    return 0;
  }
  int k = 0x7fffffff;
  k += data[0];
  // Use k.
  return k & 0;
}