skbuff: fix ftrace handling in skb_unshare

If the skb is not dropped afterwards we should run consume_skb instead
kfree_skb. Inside of function skb_unshare we do always a kfree_skb,
doesn't depend if skb_copy failed or was successful.

This patch switch this behaviour like skb_share_check, if allocation of
sk_buff failed we use kfree_skb otherwise consume_skb.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 3ab0749d6875..a59d9343c25b 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1203,7 +1203,12 @@ static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
         might_sleep_if(pri & __GFP_WAIT);
         if (skb_cloned(skb)) {
                 struct sk_buff *nskb = skb_copy(skb, pri);
-                kfree_skb(skb); /* Free our shared copy */
+
+                /* Free our shared copy */
+                if (likely(nskb))
+                        consume_skb(skb);
+                else
+                        kfree_skb(skb);
                 skb = nskb;
         }
         return skb;