net/sched: act_ct: Fix skb double-free in tcf_ct_handle_fragments() error flow

[ Upstream commit eda814b9 ]

tcf_ct_handle_fragments() shouldn't free the skb when ip_defrag() call
fails. Otherwise, we will cause a double-free bug.
In such cases, just return the error to the caller.

Fixes: b57dc7c1 ("net/sched: Introduce action ct")
Signed-off-by: Alaa Hleihel <alaa@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/sched/act_ct.c

@@ -702,7 +702,7 @@ static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb,
 		err = ip_defrag(net, skb, user);
 		local_bh_enable();
 		if (err && err != -EINPROGRESS)
-			goto out_free;
+			return err;
 
 		if (!err) {
 			*defrag = true;