From 1545996501383bd6220071c35e59aca6cd3e9b9b Mon Sep 17 00:00:00 2001
From: "Joseph C. Lehner" <joseph.c.lehner@gmail.com>
Date: Thu, 11 Jan 2024 12:25:30 +0100
Subject: [PATCH] Fix potential NULL dereference

---
 ethsock.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ethsock.c b/ethsock.c
index 3f48e4c..763cf69 100644
--- a/ethsock.c
+++ b/ethsock.c
@@ -1325,6 +1325,8 @@ static int ethsock_ip_add_del(struct ethsock *sock, uint32_t ipaddr, uint32_t ip
 
 		(*undo)->ip[0] = ipaddr;
 		(*undo)->ip[1] = ipmask;
+	} else if (!add && (!undo || !*undo)) {
+		return 0;
 	}
 
 	ret = -1;
@@ -1445,7 +1447,7 @@ int ethsock_ip_add(struct ethsock *sock, uint32_t ipaddr, uint32_t ipmask, struc
 
 int ethsock_ip_del(struct ethsock *sock, struct ethsock_ip_undo **undo)
 {
-	if (!*undo) {
+	if (!undo || !*undo) {
 		return 0;
 	}