int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm,
					       struct mutex **tfm_mutex,
					       char *cipher_name)
{
	struct ecryptfs_key_tfm *key_tfm;
	int rc = 0;

	(*tfm) = NULL;
	(*tfm_mutex) = NULL;

	mutex_lock(&key_tfm_list_mutex);
	if (!ecryptfs_tfm_exists(cipher_name, &key_tfm)) {
		rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0);
		if (rc) {
			printk(KERN_ERR "Error adding new key_tfm to list; "
					"rc = [%d]\n", rc);
			goto out;
		}
	}
	(*tfm) = key_tfm->key_tfm;
	(*tfm_mutex) = &key_tfm->key_tfm_mutex;
out:
	mutex_unlock(&key_tfm_list_mutex);
	return rc;
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.