int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
{
	struct scatterlist *sg = req->src;
	unsigned int offset = sg->offset;
	unsigned int nbytes = req->nbytes;
	int err;

	if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
		void *data;

		data = kmap_atomic(sg_page(sg));
		err = crypto_shash_digest(desc, data + offset, nbytes,
					  req->result);
		kunmap_atomic(data);
		crypto_yield(desc->flags);
	} else
		err = crypto_shash_init(desc) ?:
		      shash_ahash_finup(req, desc);

	return err;
}

This weakness pertains to the use of cryptographic functions that are weak, misconfigured, or outdated, which undermines the intended protection of encrypted data and communications.