net_sched: unify the init logic for act_police

Jamal reported a crash when we create a police action
with a specific index, this is because the init logic
is not correct, we should always create one for this
case. Just unify the logic with other tc actions.

Fixes: a03e6fe56971 ("act_police: fix a crash during removal")
Reported-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/act_police.c b/net/sched/act_police.c
index b3c7e97..259352d 100644 (file)
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -125,6 +125,7 @@ static int tcf_act_police_init(struct net *net, struct nlattr *nla,
        struct tcf_police *police;
        struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
        struct tc_action_net *tn = net_generic(net, police_net_id);
+       bool exists = false;
        int size;
 
        if (nla == NULL)
@@ -139,24 +140,24 @@ static int tcf_act_police_init(struct net *net, struct nlattr *nla,
        size = nla_len(tb[TCA_POLICE_TBF]);
        if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
                return -EINVAL;
+
        parm = nla_data(tb[TCA_POLICE_TBF]);
+       exists = tcf_hash_check(tn, parm->index, a, bind);
+       if (exists && bind)
+               return 0;
 
-       if (parm->index) {
-               if (tcf_hash_check(tn, parm->index, a, bind)) {
-                       if (ovr)
-                               goto override;
-                       /* not replacing */
-                       return -EEXIST;
-               }
-       } else {
+       if (!exists) {
                ret = tcf_hash_create(tn, parm->index, NULL, a,
                                      &act_police_ops, bind, false);
                if (ret)
                        return ret;
                ret = ACT_P_CREATED;
+       } else {
+               tcf_hash_release(*a, bind);
+               if (!ovr)
+                       return -EEXIST;
        }
 
-override:
        police = to_police(*a);
        if (parm->rate.rate) {
                err = -ENOMEM;