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 <gaozen...@jd.com>
Signed-off-by: Zhike Wang <wangzh...@jd.com>
---
net/sched/cls_api.c | 32 +++++++++++++++++++++++---------
net/sched/sch_api.c | 15 +++++++++++----
2 files changed, 34 insertions(+), 13 deletions(-)
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 478095d..15cac37 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1896,6 +1896,7 @@ 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)
@@ -1909,10 +1910,14 @@ 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,
@@ -1944,12 +1949,15 @@ 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;
}
@@ -2691,6 +2699,7 @@ 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)
@@ -2704,9 +2713,14 @@ 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,
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 352b46f..fb8f138 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -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,
- n->nlmsg_flags & NLM_F_ECHO);
+ 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,
- n->nlmsg_flags & NLM_F_ECHO);
+ 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
--
1.8.3.1
