[PATCH 4.4 49/63] sock: free skb in skb_complete_tx_timestamp on error

From: Greg Kroah-Hartman
Date: Mon Jan 01 2018 - 09:28:02 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Willem de Bruijn <willemb@xxxxxxxxxx>


[ 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 <richardcochran@xxxxxxxxx>
Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/skbuff.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3676,7 +3676,7 @@ void skb_complete_tx_timestamp(struct sk
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.
@@ -3685,7 +3685,11 @@ void skb_complete_tx_timestamp(struct sk
*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);