static int cbc_aes_decrypt(struct blkcipher_desc *desc,
			   struct scatterlist *dst, struct scatterlist *src,
			   unsigned int nbytes)
{
	struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;

	if (unlikely(need_fallback(sctx->key_len)))
		return fallback_blk_dec(desc, dst, src, nbytes);

	blkcipher_walk_init(&walk, dst, src, nbytes);
	return cbc_aes_crypt(desc, sctx->dec, &walk);
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.