static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
{
	int err;
	struct page *oldpage = *pagep;
	struct page *newpage;
	struct pipe_buffer *buf = cs->pipebufs;
	struct address_space *mapping;
	pgoff_t index;

	unlock_request(cs->fc, cs->req);
	fuse_copy_finish(cs);

	err = buf->ops->confirm(cs->pipe, buf);
	if (err)
		return err;

	BUG_ON(!cs->nr_segs);
	cs->currbuf = buf;
	cs->len = buf->len;
	cs->pipebufs++;
	cs->nr_segs--;

	if (cs->len != PAGE_SIZE)
		goto out_fallback;

	if (buf->ops->steal(cs->pipe, buf) != 0)
		goto out_fallback;

	newpage = buf->page;

	if (WARN_ON(!PageUptodate(newpage)))
		return -EIO;

	ClearPageMappedToDisk(newpage);

	if (fuse_check_page(newpage) != 0)
		goto out_fallback_unlock;

	mapping = oldpage->mapping;
	index = oldpage->index;

	/*
	 * This is a new and locked page, it shouldn't be mapped or
	 * have any special flags on it
	 */
	if (WARN_ON(page_mapped(oldpage)))
		goto out_fallback_unlock;
	if (WARN_ON(page_has_private(oldpage)))
		goto out_fallback_unlock;
	if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
		goto out_fallback_unlock;
	if (WARN_ON(PageMlocked(oldpage)))
		goto out_fallback_unlock;

	err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
	if (err) {
		unlock_page(newpage);
		return err;
	}

	page_cache_get(newpage);

	if (!(buf->flags & PIPE_BUF_FLAG_LRU))
		lru_cache_add_file(newpage);

	err = 0;
	spin_lock(&cs->fc->lock);
	if (cs->req->aborted)
		err = -ENOENT;
	else
		*pagep = newpage;
	spin_unlock(&cs->fc->lock);

	if (err) {
		unlock_page(newpage);
		page_cache_release(newpage);
		return err;
	}

	unlock_page(oldpage);
	page_cache_release(oldpage);
	cs->len = 0;

	return 0;

out_fallback_unlock:
	unlock_page(newpage);
out_fallback:
	cs->mapaddr = buf->ops->map(cs->pipe, buf, 1);
	cs->buf = cs->mapaddr + buf->offset;

	err = lock_request(cs->fc, cs->req);
	if (err)
		return err;

	return 1;
}

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.