diff --git a/src/dns_cache.c b/src/dns_cache.c
index c3c0066..2bd4b35 100644
--- a/src/dns_cache.c
+++ b/src/dns_cache.c
@@ -298,6 +298,7 @@ int dns_cache_insert(char *domain, int ttl, dns_type_t qtype, int speed, struct
 	}
 
 	if (dns_cache_head.size <= 0) {
+		dns_cache_data_free(cache_data);
 		return 0;
 	}
 
diff --git a/src/dns_client.c b/src/dns_client.c
index 37fdddb..4a4789a 100644
--- a/src/dns_client.c
+++ b/src/dns_client.c
@@ -1718,19 +1718,19 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 	const int ip_tos = SOCKET_IP_TOS;
 
 	if (server_info->ssl_ctx == NULL) {
-		tlog(TLOG_ERROR, "create ssl ctx failed.");
+		tlog(TLOG_ERROR, "create ssl ctx failed, %s", server_info->ip);
 		goto errout;
 	}
 
 	ssl = SSL_new(server_info->ssl_ctx);
 	if (ssl == NULL) {
-		tlog(TLOG_ERROR, "new ssl failed.");
+		tlog(TLOG_ERROR, "new ssl failed, %s", server_info->ip);
 		goto errout;
 	}
 
 	fd = socket(server_info->ai_family, SOCK_STREAM, 0);
 	if (fd < 0) {
-		tlog(TLOG_ERROR, "create socket failed.");
+		tlog(TLOG_ERROR, "create socket failed, %s", strerror(errno));
 		goto errout;
 	}
 
diff --git a/src/dns_server.c b/src/dns_server.c
index 9b0ed65..3dcf9a6 100644
--- a/src/dns_server.c
+++ b/src/dns_server.c
@@ -839,6 +839,7 @@ static int _dns_server_request_complete_AAAA(struct dns_request *request)
 			if (_dns_server_request_update_cache(request, DNS_T_AAAA, cache_data) != 0) {
 				goto errout;
 			}
+			cache_data = NULL;
 		}
 
 		request->has_soa = 0;
@@ -862,6 +863,7 @@ static int _dns_server_request_complete_AAAA(struct dns_request *request)
 				if (_dns_server_request_update_cache(request, DNS_T_A, cache_data) != 0) {
 					goto errout;
 				}
+				cache_data = NULL;
 			}
 
 			if (request->dualstack_selection) {
@@ -881,7 +883,7 @@ static int _dns_server_request_complete_AAAA(struct dns_request *request)
 	return 0;
 
 errout:
-	if (cache_data == NULL) {
+	if (cache_data != NULL) {
 		dns_cache_data_free(cache_data);
 		cache_data = NULL;
 	}