Commit 5b5f99b1 authored by Zhike Wang's avatar Zhike Wang Committed by David S. Miller
Browse files

net_sched: return correct value for *notify* functions 



It is confusing to directly use return value of netlink_send()/
netlink_unicast() as the return value of *notify*, as it may be not
error at all.

Example: in tc_del_tfilter(), after calling tfilter_del_notify(), it will
goto errout if (err). However, the netlink_send()/netlink_unicast() will
return positive value even for successful case. So it may not call
tcf_chain_tp_remove() and so on to clean up the resource, as a result,
resource is leaked.

It may be easier to only check the return value of tfilter_del_nofiy(),
but it is more clean to correct all related functions.

Co-developed-by: default avatarZengmo Gao <gaozengmo@jd.com>
Signed-off-by: default avatarZhike Wang <wangzhike@jd.com>
Acked-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent deb6bfab

net/sched/cls_api.c

+23 −9
Original line number Diff line number Diff line
@@ -1893,6 +1893,7 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb, 
{

	struct sk_buff *skb;

	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;

	int err = 0;



	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);

	if (!skb)
@@ -1906,10 +1907,14 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb, 
	}



	if (unicast)

		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);



	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,

		err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);

	else

		err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,

				     n->nlmsg_flags & NLM_F_ECHO);



	if (err > 0)

		err = 0;

	return err;

}



static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
@@ -1941,12 +1946,15 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb, 
	}



	if (unicast)

		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);



		err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);

	else

		err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,

				     n->nlmsg_flags & NLM_F_ECHO);

	if (err < 0)

		NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");



	if (err > 0)

		err = 0;

	return err;

}
@@ -2688,6 +2696,7 @@ static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb, 
	struct tcf_block *block = chain->block;

	struct net *net = block->net;

	struct sk_buff *skb;

	int err = 0;



	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);

	if (!skb)
@@ -2701,9 +2710,14 @@ static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb, 
	}



	if (unicast)

		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);

		err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);

	else

		err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,

				     flags & NLM_F_ECHO);



	return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);

	if (err > 0)

		err = 0;

	return err;

}



static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,

net/sched/sch_api.c

+11 −4
Original line number Diff line number Diff line
@@ -1824,6 +1824,7 @@ static int tclass_notify(struct net *net, struct sk_buff *oskb, 
{

	struct sk_buff *skb;

	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;

	int err = 0;



	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);

	if (!skb)
@@ -1834,8 +1835,11 @@ static int tclass_notify(struct net *net, struct sk_buff *oskb, 
		return -EINVAL;

	}



	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,

	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,

			     n->nlmsg_flags & NLM_F_ECHO);

	if (err > 0)

		err = 0;

	return err;

}



static int tclass_del_notify(struct net *net,
@@ -1866,8 +1870,11 @@ static int tclass_del_notify(struct net *net, 
		return err;

	}



	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,

	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,

			     n->nlmsg_flags & NLM_F_ECHO);

	if (err > 0)

		err = 0;

	return err;

}



#ifdef CONFIG_NET_CLS

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