Commit fb2b77b9 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

mpls: Convert RTM_GETNETCONF to RCU. 



mpls_netconf_get_devconf() calls __dev_get_by_index(),
and this only depends on RTNL.

Let's convert mpls_netconf_get_devconf() to RCU and use
dev_get_by_index_rcu().

Note that nlmsg_new() is moved ahead to use GFP_KERNEL.

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: default avatarGuillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/20251029173344.2934622-12-kuniyu@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent dde1b38e

net/mpls/af_mpls.c

+30 −14
Original line number Diff line number Diff line
@@ -1282,23 +1282,32 @@ static int mpls_netconf_get_devconf(struct sk_buff *in_skb, 
	if (err < 0)

		goto errout;



	if (!tb[NETCONFA_IFINDEX]) {

		err = -EINVAL;

	if (!tb[NETCONFA_IFINDEX])

		goto errout;

	}



	ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);

	dev = __dev_get_by_index(net, ifindex);

	if (!dev)

		goto errout;



	mdev = mpls_dev_get(net, dev);

	if (!mdev)

		goto errout;



	err = -ENOBUFS;

	skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);

	if (!skb)

	if (!skb) {

		err = -ENOBUFS;

		goto errout;

	}



	rcu_read_lock();



	dev = dev_get_by_index_rcu(net, ifindex);

	if (!dev) {

		err = -EINVAL;

		goto errout_unlock;

	}



	mdev = mpls_dev_rcu(dev);

	if (!mdev) {

		err = -EINVAL;

		goto errout_unlock;

	}



	err = mpls_netconf_fill_devconf(skb, mdev,

					NETLINK_CB(in_skb).portid,
@@ -1307,12 +1316,19 @@ static int mpls_netconf_get_devconf(struct sk_buff *in_skb, 
	if (err < 0) {

		/* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */

		WARN_ON(err == -EMSGSIZE);

		kfree_skb(skb);

		goto errout;

		goto errout_unlock;

	}



	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);



	rcu_read_unlock();

errout:

	return err;



errout_unlock:

	rcu_read_unlock();

	kfree_skb(skb);

	goto errout;

}



static int mpls_netconf_dump_devconf(struct sk_buff *skb,
@@ -2776,7 +2792,7 @@ static const struct rtnl_msg_handler mpls_rtnl_msg_handlers[] __initdata_or_modu 
	 RTNL_FLAG_DUMP_UNLOCKED},

	{THIS_MODULE, PF_MPLS, RTM_GETNETCONF,

	 mpls_netconf_get_devconf, mpls_netconf_dump_devconf,

	 RTNL_FLAG_DUMP_UNLOCKED},

	 RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED},

};



static int __init mpls_init(void)