[Patch net-next v2 2/4] net_sched: introduce tclass_del_notify()
flat view
STALE3345d
From: Cong Wang <hidden>
Date: 2017-08-24 23:51:56
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
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: Cong Wang <redacted> --- net/sched/sch_api.c | 39 +++++++++++++++++++++++++++++++++------ 1 file changed, 33 insertions(+), 6 deletions(-)
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 330ffaea9974..3ef4eb578739 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c@@ -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);
--
2.13.0