act_pedit: check binding before calling tcf_hash_release()

commit 5175f710 upstream.

When we share an action within a filter, the bind refcnt
should increase, therefore we should not call tcf_hash_release().

Fixes: 1a29321e ("net_sched: act: Dont increment refcnt on replace")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

net/sched/act_pedit.c

@@ -68,13 +68,12 @@ static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 		}
 		ret = ACT_P_CREATED;
 	} else {
-		p = to_pedit(a);
-		tcf_hash_release(a, bind);
 		if (bind)
 			return 0;
+		tcf_hash_release(a, bind);
 		if (!ovr)
 			return -EEXIST;
-
+		p = to_pedit(a);
 		if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
 			keys = kmalloc(ksize, GFP_KERNEL);
 			if (keys == NULL)