Index: mac_portacl.c
===================================================================
--- mac_portacl.c	(wersja 188919)
+++ mac_portacl.c	(kopia robocza)
@@ -341,10 +341,12 @@
 	int error;
 
 	new_string = NULL;
-	if (req->newptr == NULL) {
+	if (req->newptr != NULL) {
 		new_string = malloc(MAC_RULE_STRING_LEN, M_PORTACL,
 		    M_WAITOK | M_ZERO);
+		mtx_lock(&rule_mtx);
 		strcpy(new_string, rule_string);
+		mtx_unlock(&rule_mtx);
 		string = new_string;
 	} else
 		string = rule_string;