net: sched: act_ipt: remove dependency on rtnl lock

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 <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
index 0dc787a..e149f0e 100644 (file)
--- 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;