ip_tunnel_core: iptunnel_handle_offloads returns int and doesn't free skb

This patch updates the IP tunnel core function iptunnel_handle_offloads so
that we return an int and do not free the skb inside the function.  This
actually allows us to clean up several paths in several tunnels so that we
can free the skb at one point in the path without having to have a
secondary path if we are supporting tunnel offloads.

In addition it should resolve some double-free issues I have found in the
tunnels paths as I believe it is possible for us to end up triggering such
an event in the case of fou or gue.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 8 deletions

diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 43445df61efd..f46c5c873831 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -146,8 +146,8 @@ struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 }
 EXPORT_SYMBOL_GPL(iptunnel_metadata_reply);
 
-struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
-					 int gso_type_mask)
+int iptunnel_handle_offloads(struct sk_buff *skb,
+			     int gso_type_mask)
 {
 	int err;
 
@@ -159,9 +159,9 @@ struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
 	if (skb_is_gso(skb)) {
 		err = skb_unclone(skb, GFP_ATOMIC);
 		if (unlikely(err))
-			goto error;
+			return err;
 		skb_shinfo(skb)->gso_type |= gso_type_mask;
-		return skb;
+		return 0;
 	}
 
 	if (skb->ip_summed != CHECKSUM_PARTIAL) {
@@ -174,10 +174,7 @@ struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
 		skb->encapsulation = 0;
 	}
 
-	return skb;
-error:
-	kfree_skb(skb);
-	return ERR_PTR(err);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);