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Commit 0b2a5989 authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

cls_basic: use tcf_exts_get_net() before call_rcu() 



Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e4b95c41

net/sched/cls_basic.c

+15 −5
Original line number Diff line number Diff line
@@ -85,16 +85,21 @@ static int basic_init(struct tcf_proto *tp) 
	return 0;

}



static void __basic_delete_filter(struct basic_filter *f)

{

	tcf_exts_destroy(&f->exts);

	tcf_em_tree_destroy(&f->ematches);

	tcf_exts_put_net(&f->exts);

	kfree(f);

}



static void basic_delete_filter_work(struct work_struct *work)

{

	struct basic_filter *f = container_of(work, struct basic_filter, work);



	rtnl_lock();

	tcf_exts_destroy(&f->exts);

	tcf_em_tree_destroy(&f->ematches);

	__basic_delete_filter(f);

	rtnl_unlock();



	kfree(f);

}



static void basic_delete_filter(struct rcu_head *head)
@@ -113,7 +118,10 @@ static void basic_destroy(struct tcf_proto *tp) 
	list_for_each_entry_safe(f, n, &head->flist, link) {

		list_del_rcu(&f->link);

		tcf_unbind_filter(tp, &f->res);

		if (tcf_exts_get_net(&f->exts))

			call_rcu(&f->rcu, basic_delete_filter);

		else

			__basic_delete_filter(f);

	}

	kfree_rcu(head, rcu);

}
@@ -125,6 +133,7 @@ static int basic_delete(struct tcf_proto *tp, void *arg, bool *last) 


	list_del_rcu(&f->link);

	tcf_unbind_filter(tp, &f->res);

	tcf_exts_get_net(&f->exts);

	call_rcu(&f->rcu, basic_delete_filter);

	*last = list_empty(&head->flist);

	return 0;
@@ -219,6 +228,7 @@ static int basic_change(struct net *net, struct sk_buff *in_skb, 
	if (fold) {

		list_replace_rcu(&fold->link, &fnew->link);

		tcf_unbind_filter(tp, &fold->res);

		tcf_exts_get_net(&fold->exts);

		call_rcu(&fold->rcu, basic_delete_filter);

	} else {

		list_add_rcu(&fnew->link, &head->flist);