diff --git a/include/net/ip.h b/include/net/ip.h
index 9b9ca2839399..525dc0778926 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -282,10 +282,12 @@ int ip_decrease_ttl(struct iphdr *iph)
 }
 
 static inline
-int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
+int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
 {
-	return  inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
-		(inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
+	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
+
+	return  pmtudisc == IP_PMTUDISC_DO ||
+		(pmtudisc == IP_PMTUDISC_WANT &&
 		 !(dst_metric_locked(dst, RTAX_MTU)));
 }