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: Zengmo Gao <gaozengmo@jd.com>
Signed-off-by: Zhike Wang <wangzhike@jd.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 2c2aac4..dc10525 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -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);
+ err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
+ else
+ err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
+ n->nlmsg_flags & NLM_F_ECHO);
- return 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 = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
- n->nlmsg_flags & NLM_F_ECHO);
+ 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,