Commit 14546ba1 authored by WANG Cong's avatar WANG Cong Committed by David S. Miller

net_sched: introduce tclass_del_notify()

Like for TC actions, ->delete() is a special case,
we have to prepare and fill the notification before delete
otherwise would get use-after-free after we remove the
reference count.
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Acked-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 27d7f07c
......@@ -1618,6 +1618,38 @@ static int tclass_notify(struct net *net, struct sk_buff *oskb,
n->nlmsg_flags & NLM_F_ECHO);
}
static int tclass_del_notify(struct net *net,
const struct Qdisc_class_ops *cops,
struct sk_buff *oskb, struct nlmsghdr *n,
struct Qdisc *q, unsigned long cl)
{
u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
struct sk_buff *skb;
int err = 0;
if (!cops->delete)
return -EOPNOTSUPP;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
RTM_DELTCLASS) < 0) {
kfree_skb(skb);
return -EINVAL;
}
err = cops->delete(q, cl);
if (err) {
kfree_skb(skb);
return err;
}
return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
}
static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
struct netlink_ext_ack *extack)
{
......@@ -1722,12 +1754,7 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
goto out;
break;
case RTM_DELTCLASS:
err = -EOPNOTSUPP;
if (cops->delete)
err = cops->delete(q, cl);
if (err == 0)
tclass_notify(net, skb, n, q, cl,
RTM_DELTCLASS);
err = tclass_del_notify(net, cops, skb, n, q, cl);
goto out;
case RTM_GETTCLASS:
err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
......
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