xfrm: Verify MAC header exists before overwriting eth_hdr(skb)->h_proto

[mirror_ubuntu-bionic-kernel.git] / net / ipv6 / xfrm6_mode_tunnel.c

diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index dc93002ff9d1b88a9ac4ec750ae38f89c25dca73..1ff2cffaa23800b357f7a2621b0f922942f57cc5 100644 (file)
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -92,7 +92,8 @@ static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 
        skb_reset_network_header(skb);
        skb_mac_header_rebuild(skb);
-       eth_hdr(skb)->h_proto = skb->protocol;
+       if (skb->mac_len)
+               eth_hdr(skb)->h_proto = skb->protocol;
 
        err = 0;