- Fix that malloc failure for ngtcp2_conn_server_new

cleans up reference that older ngtcp2 versions can leave.
  Thanks to Qifan Zhang, Palo Alto Networks, for the report.

doc/Changelog

@@ -26,6 +26,9 @@
 	- Fix that malloc failure in doq connection setup, does
 	  not crash in doq connection delete later. Thanks to Qifan
 	  Zhang, Palo Alto Networks, for the report.
+	- Fix that malloc failure for ngtcp2_conn_server_new
+	  cleans up reference that older ngtcp2 versions can leave.
+	  Thanks to Qifan Zhang, Palo Alto Networks, for the report.
 
 16 June 2026: Wouter
 	- Fix to disallow $INCLUDE for secondary zones. Start up

services/listen_dnsport.c

@@ -4881,6 +4881,7 @@ doq_conn_setup(struct doq_conn* conn, uint8_t* scid, size_t scidlen,
 	rv = ngtcp2_conn_server_new(&conn->conn, &scid_cid, &sv_scid, &path,
 		conn->version, &callbacks, &settings, &params, NULL, conn);
 	if(rv != 0) {
+		conn->conn = NULL;
 		lock_rw_unlock(&conn->table->conid_lock);
 		log_err("ngtcp2_conn_server_new failed: %s",
 			ngtcp2_strerror(rv));

testcode/doqclient.c

@@ -1137,8 +1137,11 @@ static struct ngtcp2_conn* conn_client_setup(struct doq_client_data* data)
 		client_chosen_version, &cbs, &settings, &params,
 		NULL, /* ngtcp2_mem allocator, use default */
 		data /* callback argument */);
-	if(!conn) fatal_exit("could not ngtcp2_conn_client_new: %s",
-		ngtcp2_strerror(rv));
+	if(rv!=0) {
+		conn = NULL;
+		fatal_exit("could not ngtcp2_conn_client_new: %s",
+			ngtcp2_strerror(rv));
+	}
 	data->cc_algo = settings.cc_algo;
 	return conn;
 }