xfrm: Fix pmtu discovery for local generated packets.
Commit 044a832a777 ("xfrm: Fix local error reporting crash
with interfamily tunnels") moved the setting of skb->protocol
behind the last access of the inner mode family to fix an
interfamily crash. Unfortunately now skb->protocol might not
be set at all, so we fail dispatch to the inner address family.
As a reault, the local error handler is not called and the
mtu value is not reported back to userspace.
We fix this by setting skb->protocol on message size errors
before we call xfrm_local_error.
Fixes: 044a832a7779c ("xfrm: Fix local error reporting crash with interfamily tunnels")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index be033f2..e15feb7 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -79,6 +79,7 @@
if (!skb->ignore_df && skb->len > mtu) {
skb->dev = dst->dev;
+ skb->protocol = htons(ETH_P_IPV6);
if (xfrm6_local_dontfrag(skb))
xfrm6_local_rxpmtu(skb, mtu);