brotli/dec/safe_malloc.c

// Copyright 2013 Google Inc. All Rights Reserved.
//
// 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.
//
// Size-checked memory allocation.

#include <stdlib.h>
#include "./safe_malloc.h"

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

// Returns 0 in case of overflow of nmemb * size.
static int CheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
  const uint64_t total_size = nmemb * size;
  if (nmemb == 0) return 1;
  if ((uint64_t)size > BROTLI_MAX_ALLOCABLE_MEMORY / nmemb) return 0;
  if (total_size != (size_t)total_size) return 0;
  return 1;
}

void* BrotliSafeMalloc(uint64_t nmemb, size_t size) {
  if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL;
  assert(nmemb * size > 0);
  return malloc((size_t)(nmemb * size));
}

#if defined(__cplusplus) || defined(c_plusplus)
}    // extern "C"
#endif