diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index c5b4b586570f..25134a3548e9 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -515,21 +515,24 @@ struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
 	unsigned int off = skb_gro_offset(skb);
 	int flush = 1;
 
+	/* we can do L4 aggregation only if the packet can't land in a tunnel
+	 * otherwise we could corrupt the inner stream
+	 */
 	NAPI_GRO_CB(skb)->is_flist = 0;
-	if (skb->dev->features & NETIF_F_GRO_FRAGLIST)
-		NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1;
+	if (!sk || !udp_sk(sk)->gro_receive) {
+		if (skb->dev->features & NETIF_F_GRO_FRAGLIST)
+			NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled : 1;
 
-	if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) ||
-	    (sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) {
-		pp = call_gro_receive(udp_gro_receive_segment, head, skb);
+		if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) ||
+		    (sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist)
+			pp = call_gro_receive(udp_gro_receive_segment, head, skb);
 		return pp;
 	}
 
-	if (!sk || NAPI_GRO_CB(skb)->encap_mark ||
+	if (NAPI_GRO_CB(skb)->encap_mark ||
 	    (uh->check && skb->ip_summed != CHECKSUM_PARTIAL &&
 	     NAPI_GRO_CB(skb)->csum_cnt == 0 &&
-	     !NAPI_GRO_CB(skb)->csum_valid) ||
-	    !udp_sk(sk)->gro_receive)
+	     !NAPI_GRO_CB(skb)->csum_valid))
 		goto out;
 
 	/* mark that this skb passed once through the tunnel gro layer */