diff
--- a/rtm_phonet_notify.c
+++ b/rtm_phonet_notify.c
@@ -4,6 +4,9 @@
 	struct sk_buff *skb;
 
 6-	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
+	if (extra_data_len > MAX_EXTRA_DATA_SIZE) {
+		// Handle error (e.g., return error code, log)
+	}
+	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) + extra_data_len, 
 
 