net/tls: Fix memory leak in tls_enc_skb() and tls_sw_fallback_init()

'aead_req' and 'aead_send' is allocated but not freed in default switch
case. This commit fixes the potential memory leak by freeing them under
the situation.

Note that the default cases here should never be reached as they'd
mean we allowed offloading an unsupported algorithm.

Fixes: ea7a9d8 ("net/tls: Use cipher sizes structs")
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Link: https://lore.kernel.org/r/20221110090329.2036382-1-liaoyu15@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/tls/tls_device_fallback.c

@@ -346,7 +346,7 @@ static struct sk_buff *tls_enc_skb(struct tls_context *tls_ctx,
 		salt = tls_ctx->crypto_send.aes_gcm_256.salt;
 		break;
 	default:
-		return NULL;
+		goto free_req;
 	}
 	cipher_sz = &tls_cipher_size_desc[tls_ctx->crypto_send.info.cipher_type];
 	buf_len = cipher_sz->salt + cipher_sz->iv + TLS_AAD_SPACE_SIZE +
@@ -492,7 +492,8 @@ int tls_sw_fallback_init(struct sock *sk,
 		key = ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->key;
 		break;
 	default:
-		return -EINVAL;
+		rc = -EINVAL;
+		goto free_aead;
 	}
 	cipher_sz = &tls_cipher_size_desc[crypto_info->cipher_type];