diff mbox series

[net,09/13] cls_matchall: use tcf_exts_get_net() before call_rcu()

Message ID 20171106214730.24421-10-xiyou.wangcong@gmail.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series net_sched: close the race between call_rcu() and cleanup_net() | expand

Commit Message

Cong Wang Nov. 6, 2017, 9:47 p.m. UTC 
Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 net/sched/cls_matchall.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index c33f711b9019..3684153cd8a9 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -44,13 +44,19 @@  static int mall_init(struct tcf_proto *tp)
 	return 0;
 }
 
+static void __mall_destroy(struct cls_mall_head *head)
+{
+	tcf_exts_destroy(&head->exts);
+	tcf_exts_put_net(&head->exts);
+	kfree(head);
+}
+
 static void mall_destroy_work(struct work_struct *work)
 {
 	struct cls_mall_head *head = container_of(work, struct cls_mall_head,
 						  work);
 	rtnl_lock();
-	tcf_exts_destroy(&head->exts);
-	kfree(head);
+	__mall_destroy(head);
 	rtnl_unlock();
 }
 
@@ -109,7 +115,10 @@  static void mall_destroy(struct tcf_proto *tp)
 	if (tc_should_offload(dev, head->flags))
 		mall_destroy_hw_filter(tp, head, (unsigned long) head);
 
-	call_rcu(&head->rcu, mall_destroy_rcu);
+	if (tcf_exts_get_net(&head->exts))
+		call_rcu(&head->rcu, mall_destroy_rcu);
+	else
+		__mall_destroy(head);
 }
 
 static void *mall_get(struct tcf_proto *tp, u32 handle)