xfrm: Reset encapsulation field of the skb before transformation

The inner headers are invalid after a xfrm transformation.
So reset the skb encapsulation field to ensure nobody tries
to access the inner headers.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index ff4a91fcab9f..637387bbaaea 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -99,6 +99,9 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
 
                 skb_dst_force(skb);
 
+                /* Inner headers are invalid now. */
+                skb->encapsulation = 0;
+
                 err = x->type->output(x, skb);
                 if (err == -EINPROGRESS)
                         goto out;