[PATCH 4.14 086/146] sock: free skb in skb_complete_tx_timestamp on error

Greg Kroah-Hartman
2018-01-01T14:43:56Z

From: Willem de Bruijn <willemb@google.com>

[ 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@gmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/core/skbuff.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4296,7 +4296,7 @@ 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.
@@ -4305,7 +4305,11 @@ void skb_complete_tx_timestamp(struct sk
*skb_hwtstamps(skb) = *hwtstamps;
__skb_complete_tx_timestamp(skb, sk, SCM_TSTAMP_SND, false);
sock_put(sk);
+ return;
}
+
+err:
+ kfree_skb(skb);
}
EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);