net: sched: act_ipt: remove dependency on rtnl lock

w1ldptr · davem330 · commit ff25276de997 · 2018-08-11T12:37:09.000-07:00
Use tcf spinlock to protect ipt action private data from concurrent
modification during dump. Ipt init already takes tcf spinlock when
modifying ipt state.

Signed-off-by: Vlad Buslov &lt;vladbu@mellanox.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
@@ -288,6 +288,7 @@ static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 	 * for foolproof you need to not assume this
 	 */
 
+	spin_lock_bh(&ipt->tcf_lock);
 	t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC);
 	if (unlikely(!t))
 		goto nla_put_failure;
@@ -307,10 +308,12 @@ static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 	if (nla_put_64bit(skb, TCA_IPT_TM, sizeof(tm), &tm, TCA_IPT_PAD))
 		goto nla_put_failure;
 
+	spin_unlock_bh(&ipt->tcf_lock);
 	kfree(t);
 	return skb->len;
 
 nla_put_failure:
+	spin_unlock_bh(&ipt->tcf_lock);
 	nlmsg_trim(skb, b);
 	kfree(t);
 	return -1;
