diff --git a/include/net/route.h b/include/net/route.h
index 2ea40c1b5e009746dacb8f146fdcc37309aa7ff3..afdeeb5bec251ac773f03d8c7f0b830c9fa137e2 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -317,4 +317,12 @@ static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
 	return hoplimit;
 }
 
+static inline int ip_skb_dst_mtu(struct sk_buff *skb)
+{
+	struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL;
+
+	return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ?
+	       skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
+}
+
 #endif	/* _ROUTE_H */
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index e823786e7c66a6763e1cfa29bfcc76a3b4f7f6ba..b41d2d10ff0e2088b14ba3513b5483bb3df6786c 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -20,6 +20,7 @@
 #include <net/route.h>
 #include <net/ipv6.h>
 #include <net/ip6_fib.h>
+#include <net/ip6_route.h>
 #include <net/flow.h>
 
 #include <linux/interrupt.h>
@@ -1723,4 +1724,15 @@ static inline int xfrm_mark_put(struct sk_buff *skb, const struct xfrm_mark *m)
 	return ret;
 }
 
+static inline int xfrm_skb_dst_mtu(struct sk_buff *skb)
+{
+	struct sock *sk = skb->sk;
+
+	if (sk && sk->sk_family == AF_INET6)
+		return ip6_skb_dst_mtu(skb);
+	else if (sk && sk->sk_family == AF_INET)
+		return ip_skb_dst_mtu(skb);
+	return dst_mtu(skb_dst(skb));
+}
+
 #endif	/* _NET_XFRM_H */
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 4bcabf3ab4cad3bdc43f5b9ed33eba9c1357557d..9ee17e3d11c30e4054558729df205b41a762e806 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -211,14 +211,6 @@ static inline int ip_finish_output2(struct sk_buff *skb)
 	return -EINVAL;
 }
 
-static inline int ip_skb_dst_mtu(struct sk_buff *skb)
-{
-	struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL;
-
-	return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ?
-	       skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
-}
-
 static int ip_finish_output(struct sk_buff *skb)
 {
 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index 7a5491ffa4dec99e6e300bc349d4cfcbf1389b8b..80baf4a3b1b5cae54aa4827fe33ab733c12ed171 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -21,7 +21,6 @@
 static int xfrm4_tunnel_check_size(struct sk_buff *skb)
 {
 	int mtu, ret = 0;
-	struct dst_entry *dst;
 
 	if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
 		goto out;
@@ -29,8 +28,7 @@ static int xfrm4_tunnel_check_size(struct sk_buff *skb)
 	if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df)
 		goto out;
 
-	dst = skb_dst(skb);
-	mtu = dst_mtu(dst);
+	mtu = xfrm_skb_dst_mtu(skb);
 	if (skb->len > mtu) {
 		if (skb->sk)
 			xfrm_local_error(skb, mtu);
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index b64fff30eb064ddf47e5c97744d5fa9831365a6b..3ac5ab264fedd3dcb7988eb47782c1835ea3c234 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -138,7 +138,10 @@ static int __xfrm6_output(struct sk_buff *skb)
 {
 	struct dst_entry *dst = skb_dst(skb);
 	struct xfrm_state *x = dst->xfrm;
-	int mtu = ip6_skb_dst_mtu(skb);
+	int mtu = xfrm_skb_dst_mtu(skb);
+
+	if (mtu < IPV6_MIN_MTU)
+		mtu = IPV6_MIN_MTU;
 
 	if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
 		xfrm6_local_rxpmtu(skb, mtu);