net_sched: act: Delete estimator in error path.

Some action modules free struct tcf_common in their error path
while estimator is still active. This results in est_timer()
dereference freed memory.
Add gen_kill_estimator() in ipt, pedit and simple action.
Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/act_ipt.c

@@ -185,7 +185,12 @@ static int tcf_ipt_init(struct nlattr *nla, struct nlattr *est,
 err2:
 	kfree(tname);
 err1:
-	kfree(pc);
+	if (ret == ACT_P_CREATED) {
+		if (est)
+			gen_kill_estimator(&pc->tcfc_bstats,
+					   &pc->tcfc_rate_est);
+		kfree_rcu(pc, tcfc_rcu);
+	}
 	return err;
 }
 

net/sched/act_pedit.c

@@ -74,7 +74,10 @@ static int tcf_pedit_init(struct nlattr *nla, struct nlattr *est,
 		p = to_pedit(pc);
 		keys = kmalloc(ksize, GFP_KERNEL);
 		if (keys == NULL) {
-			kfree(pc);
+			if (est)
+				gen_kill_estimator(&pc->tcfc_bstats,
+						   &pc->tcfc_rate_est);
+			kfree_rcu(pc, tcfc_rcu);
 			return -ENOMEM;
 		}
 		ret = ACT_P_CREATED;

net/sched/act_simple.c

@@ -131,7 +131,10 @@ static int tcf_simp_init(struct nlattr *nla, struct nlattr *est,
 		d = to_defact(pc);
 		ret = alloc_defdata(d, defdata);
 		if (ret < 0) {
-			kfree(pc);
+			if (est)
+				gen_kill_estimator(&pc->tcfc_bstats,
+						   &pc->tcfc_rate_est);
+			kfree_rcu(pc, tcfc_rcu);
 			return ret;
 		}
 		d->tcf_action = parm->action;