xfrm: Fix skb double-free in xfrm_dev_direct_output()
A return value other than 1 from local_out() means that the skb has been
consumed or its ownership was transferred. xfrm_dev_direct_output()
nevertheless frees the skb on this path, causing a double-free when
netfilter drops the packet and invalidating any other owner.
Return the local_out() result directly, matching the ownership handling
in xfrm_output_resume().
Fixes: 5eddd76ec2fd ("xfrm: fix tunnel mode TX datapath in packet offload mode")
Signed-off-by: Sanghyun Park <sanghyun.park.cnu@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index cc35c2f..e305ba3 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -636,10 +636,8 @@ static int xfrm_dev_direct_output(struct sock *sk, struct xfrm_state *x,
nf_reset_ct(skb);
err = skb_dst(skb)->ops->local_out(net, sk, skb);
- if (unlikely(err != 1)) {
- kfree_skb(skb);
+ if (unlikely(err != 1))
return err;
- }
/* In transport mode, network destination is
* directly reachable, while in tunnel mode,
