u8 ecryptfs_code_for_cipher_string(char *cipher_name, size_t key_bytes)
{
	int i;
	u8 code = 0;
	struct ecryptfs_cipher_code_str_map_elem *map =
		ecryptfs_cipher_code_str_map;

	if (strcmp(cipher_name, "aes") == 0) {
		switch (key_bytes) {
		case 16:
			code = RFC2440_CIPHER_AES_128;
			break;
		case 24:
			code = RFC2440_CIPHER_AES_192;
			break;
		case 32:
			code = RFC2440_CIPHER_AES_256;
		}
	} else {
		for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++)
			if (strcmp(cipher_name, map[i].cipher_str) == 0) {
				code = map[i].cipher_code;
				break;
			}
	}
	return code;
}

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