create_code(struct archive_read *a, struct huffman_code *code,
            unsigned char *lengths, int numsymbols, char maxlength)
{
  int i, j, codebits = 0, symbolsleft = numsymbols;

  code->numentries = 0;
  code->numallocatedentries = 0;
  if (new_node(code) < 0) {
    archive_set_error(&a->archive, ENOMEM,
                      "Unable to allocate memory for node data.");
    return (ARCHIVE_FATAL);
  }
  code->numentries = 1;
  code->minlength = INT_MAX;
  code->maxlength = INT_MIN;
  codebits = 0;
  for(i = 1; i <= maxlength; i++)
  {
    for(j = 0; j < numsymbols; j++)
    {
      if (lengths[j] != i) continue;
      if (add_value(a, code, j, codebits, i) != ARCHIVE_OK)
        return (ARCHIVE_FATAL);
      codebits++;
      if (--symbolsleft <= 0) { break; break; }
    }
    codebits <<= 1;
  }
  return (ARCHIVE_OK);
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.