内存泄漏通过new []而没有调用new

Question

我从以下函数中获取内存泄漏:

int ReadWrite(int socket, char *readfile) {
  FILE *rf = NULL;
  rf = fopen(readfile, "rb");
  fseek(rf, 0, SEEK_END);
  int len = ftell(rf);
  rewind(rf);

  char readbuf[len + 1];

  int res = fread(readbuf, len, 1, rf);
  readbuf[len + 1] = '\0';
  fclose(rf);
  while (1) {
    int wres = write(socket, readbuf, res);
    if (wres == 0) {
      cerr << "socket closed prematurely" << endl;
      close(socket);
      return EXIT_FAILURE;
    }
    if (res == -1) {
      if (errno == EINTR)
        continue;
      cerr << "socket write failure: " << strerror(errno) << endl;
      close(socket);
      return EXIT_FAILURE;
    }
    break;
  }
  return EXIT_SUCCESS;
}

Valgrind告诉我通过这个操作泄漏readfile中的字节数(实际文件,而不是readfile的名称):

Address 0x4c3b67e is 0 bytes after a block of size 14 alloc'd
at 0x4A07C84: operator new[](unsigned long) (vg_replace_malloc.c:363)

令我困惑的是我在代码中没有使用new [].我检查了fopen,ftell和fread,看看他们是否隐藏了"gotcha's",他们在某处调用new [],但在cplusplus.com的文档中没有找到任何内容.我已经尝试了新的char []/delete [],malloc/free和stack-allocated变量(上面)的所有不同组合,但每次都得到相同的valgrind消息.有任何想法吗？谢谢.

Answer 1

你打电话

• char readbuf[len + 1];

  然后是

• readbuf[len + 1] = '\0';

不会溢出阵列？