static BrotliResult WriteRingBuffer(size_t* available_out, uint8_t** next_out,
    size_t* total_out, BrotliState* s) {
  size_t pos = (s->pos > s->ringbuffer_size) ?
      (size_t)s->ringbuffer_size : (size_t)(s->pos);
  uint8_t* start = s->ringbuffer
      + (s->partial_pos_out & (size_t)s->ringbuffer_mask);
  size_t partial_pos_rb =
      (s->rb_roundtrips * (size_t)s->ringbuffer_size) + pos;
  size_t to_write = (partial_pos_rb - s->partial_pos_out);
  size_t num_written = *available_out;
  if (num_written > to_write) {
    num_written = to_write;
  }
  if (s->meta_block_remaining_len < 0) {
    return BROTLI_FAILURE();
  }
  memcpy(*next_out, start, num_written);
  *next_out += num_written;
  *available_out -= num_written;
  BROTLI_LOG_UINT(to_write);
  BROTLI_LOG_UINT(num_written);
  s->partial_pos_out += (size_t)num_written;
  *total_out = s->partial_pos_out;
  if (num_written < to_write) {
    return BROTLI_RESULT_NEEDS_MORE_OUTPUT;
  }
  return BROTLI_RESULT_SUCCESS;
}

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.