diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 5b1050a..f509f7b 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2139,9 +2139,12 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 
 	if (res.type == RTN_LOCAL) {
 		int result;
+		int mark = 0;
+		if (sysctl_mark_validate_source)
+			mark = skb->mark;
 		result = fib_validate_source(saddr, daddr, tos,
 					     net->loopback_dev->ifindex,
-					     dev, &spec_dst, &itag, skb->mark);
+					     dev, &spec_dst, &itag, mark);
 		if (result < 0)
 			goto martian_source;
 		if (result)