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Commit eb1fb147 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
Browse files

netfilter: nft_compat: use call_rcu for nfnl_compat_get 



Just use .call_rcu instead.  We can drop the rcu read lock
after obtaining a reference and re-acquire on return.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 88491c11

net/netfilter/nft_compat.c

+18 −11
Original line number Diff line number Diff line
@@ -611,7 +611,7 @@ nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, 
	return -1;

}



static int nfnl_compat_get(struct net *net, struct sock *nfnl,

static int nfnl_compat_get_rcu(struct net *net, struct sock *nfnl,

			       struct sk_buff *skb, const struct nlmsghdr *nlh,

			       const struct nlattr * const tb[],

			       struct netlink_ext_ack *extack)
@@ -653,16 +653,21 @@ static int nfnl_compat_get(struct net *net, struct sock *nfnl, 
		return -EINVAL;

	}



	if (!try_module_get(THIS_MODULE))

		return -EINVAL;



	rcu_read_unlock();

	try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,

						 rev, target, &ret),

						 fmt, name);



	if (ret < 0)

		return ret;

		goto out_put;



	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (skb2 == NULL)

		return -ENOMEM;

	if (skb2 == NULL) {

		ret = -ENOMEM;

		goto out_put;

	}



	/* include the best revision for this extension in the message */

	if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
@@ -672,14 +677,16 @@ static int nfnl_compat_get(struct net *net, struct sock *nfnl, 
				  nfmsg->nfgen_family,

				  name, ret, target) <= 0) {

		kfree_skb(skb2);

		return -ENOSPC;

		goto out_put;

	}



	ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,

				MSG_DONTWAIT);

	if (ret > 0)

		ret = 0;



out_put:

	rcu_read_lock();

	module_put(THIS_MODULE);

	return ret == -EAGAIN ? -ENOBUFS : ret;

}
@@ -691,7 +698,7 @@ static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = { 
};



static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {

	[NFNL_MSG_COMPAT_GET]		= { .call = nfnl_compat_get,

	[NFNL_MSG_COMPAT_GET]		= { .call_rcu = nfnl_compat_get_rcu,

					    .attr_count = NFTA_COMPAT_MAX,

					    .policy = nfnl_compat_policy_get },

};