Subject: [PATCH 22/33] sock: free skb in skb_complete_tx_timestamp on error

From: Willem de Bruijn <[email-masked]>
Date: Wed, 13 Dec 2017 14:41:06 -0500

[ Upstream commit 35b99dffc3f710cafceee6c8c6ac6a98eb2cb4bf ]

skb_complete_tx_timestamp must ingest the skb it is passed. Call
kfree_skb if the skb cannot be enqueued.

Fixes: b245be1f4db1 ("net-timestamp: no-payload only sysctl")
Fixes: 9ac25fc06375 ("net: fix socket refcounting in skb_complete_tx_timestamp()")
Reported-by: Richard Cochran <[email-masked]>
Signed-off-by: Willem de Bruijn <[email-masked]>
Reviewed-by: Eric Dumazet <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/core/skbuff.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index aec5605..a645155 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3823,7 +3823,7 @@ void skb_complete_tx_timestamp(struct sk_buff *skb,
 	struct sock *sk = skb->sk;
 
 	if (!skb_may_tx_timestamp(sk, false))
-		return;
+		goto err;
 
 	/* Take a reference to prevent skb_orphan() from freeing the socket,
 	 * but only if the socket refcount is not zero.
@@ -3832,7 +3832,11 @@ void skb_complete_tx_timestamp(struct sk_buff *skb,
 		*skb_hwtstamps(skb) = *hwtstamps;
 		__skb_complete_tx_timestamp(skb, sk, SCM_TSTAMP_SND);
 		sock_put(sk);
+		return;
 	}
+
+err:
+	kfree_skb(skb);
 }
 EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
 
-- 
2.9.5