diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 6ec86f1a2ed96d809e4a6a4579c0325886e77bb5..cf906d1ce8a7fb29522388e174e975863d797b41 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3702,5 +3702,29 @@ static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
 	return hdr_len + skb_gso_transport_seglen(skb);
 }
 
+/* Local Checksum Offload.
+ * Compute outer checksum based on the assumption that the
+ * inner checksum will be offloaded later.
+ * Fill in outer checksum adjustment (e.g. with sum of outer
+ * pseudo-header) before calling.
+ * Also ensure that inner checksum is in linear data area.
+ */
+static inline __wsum lco_csum(struct sk_buff *skb)
+{
+	char *inner_csum_field;
+	__wsum csum;
+
+	/* Start with complement of inner checksum adjustment */
+	inner_csum_field = skb->data + skb_checksum_start_offset(skb) +
+				skb->csum_offset;
+	csum = ~csum_unfold(*(__force __sum16 *)inner_csum_field);
+	/* Add in checksum of our headers (incl. outer checksum
+	 * adjustment filled in by caller)
+	 */
+	csum = skb_checksum(skb, 0, skb_checksum_start_offset(skb), csum);
+	/* The result is the checksum from skb->data to end of packet */
+	return csum;
+}
+
 #endif	/* __KERNEL__ */
 #endif	/* _LINUX_SKBUFF_H */
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 859d415c0b2dc84512798592eec9f2af26ec2837..d74ce93de1fec37d5f151471f6ffbaad9cb8da23 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -166,20 +166,20 @@ struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
 		return skb;
 	}
 
-	/* If packet is not gso and we are resolving any partial checksum,
+	/* If packet is not gso and we are not offloading inner checksum,
 	 * clear encapsulation flag. This allows setting CHECKSUM_PARTIAL
 	 * on the outer header without confusing devices that implement
 	 * NETIF_F_IP_CSUM with encapsulation.
 	 */
-	if (csum_help)
-		skb->encapsulation = 0;
-
 	if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) {
+		skb->encapsulation = 0;
 		err = skb_checksum_help(skb);
 		if (unlikely(err))
 			goto error;
-	} else if (skb->ip_summed != CHECKSUM_PARTIAL)
+	} else if (skb->ip_summed != CHECKSUM_PARTIAL) {
 		skb->ip_summed = CHECKSUM_NONE;
+		skb->encapsulation = 0;
+	}
 
 	return skb;
 error:
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ac3cedb25a9f02fd648c808cd24f5f17f3cd81d7..a59341cf483edffe4a3911131bb4ab9498328d51 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -848,16 +848,18 @@ void udp_set_csum(bool nocheck, struct sk_buff *skb,
 {
 	struct udphdr *uh = udp_hdr(skb);
 
-	if (nocheck)
+	if (nocheck) {
 		uh->check = 0;
-	else if (skb_is_gso(skb))
+	} else if (skb_is_gso(skb)) {
 		uh->check = ~udp_v4_check(len, saddr, daddr, 0);
-	else if (skb_dst(skb) && skb_dst(skb)->dev &&
-		 (skb_dst(skb)->dev->features &
-		  (NETIF_F_IP_CSUM | NETIF_F_HW_CSUM))) {
-
-		BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
-
+	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		uh->check = 0;
+		uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
+		if (uh->check == 0)
+			uh->check = CSUM_MANGLED_0;
+	} else if (skb_dst(skb) && skb_dst(skb)->dev &&
+		   (skb_dst(skb)->dev->features &
+		    (NETIF_F_IP_CSUM | NETIF_F_HW_CSUM))) {
 		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb->csum_start = skb_transport_header(skb) - skb->head;
 		skb->csum_offset = offsetof(struct udphdr, check);
@@ -865,8 +867,6 @@ void udp_set_csum(bool nocheck, struct sk_buff *skb,
 	} else {
 		__wsum csum;
 
-		BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
-
 		uh->check = 0;
 		csum = skb_checksum(skb, 0, len, 0);
 		uh->check = udp_v4_check(len, saddr, daddr, csum);
diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
index 9a4d7322fb22234c5d697c384a74949beb2e50c5..4924bd704e896bbead932d6ebfbec7c10bb0dc0c 100644
--- a/net/ipv6/ip6_checksum.c
+++ b/net/ipv6/ip6_checksum.c
@@ -98,11 +98,13 @@ void udp6_set_csum(bool nocheck, struct sk_buff *skb,
 		uh->check = 0;
 	else if (skb_is_gso(skb))
 		uh->check = ~udp_v6_check(len, saddr, daddr, 0);
-	else if (skb_dst(skb) && skb_dst(skb)->dev &&
-		 (skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) {
-
-		BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
-
+	else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		uh->check = 0;
+		uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
+		if (uh->check == 0)
+			uh->check = CSUM_MANGLED_0;
+	} else if (skb_dst(skb) && skb_dst(skb)->dev &&
+		   (skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) {
 		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb->csum_start = skb_transport_header(skb) - skb->head;
 		skb->csum_offset = offsetof(struct udphdr, check);
@@ -110,8 +112,6 @@ void udp6_set_csum(bool nocheck, struct sk_buff *skb,
 	} else {
 		__wsum csum;
 
-		BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
-
 		uh->check = 0;
 		csum = skb_checksum(skb, 0, len, 0);
 		uh->check = udp_v6_check(len, saddr, daddr, csum);