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Commit d5f984f5 authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

cls_fw: 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 0dadc117

net/sched/cls_fw.c

+14 −3
Original line number Diff line number Diff line
@@ -122,13 +122,19 @@ static int fw_init(struct tcf_proto *tp) 
	return 0;

}



static void __fw_delete_filter(struct fw_filter *f)

{

	tcf_exts_destroy(&f->exts);

	tcf_exts_put_net(&f->exts);

	kfree(f);

}



static void fw_delete_filter_work(struct work_struct *work)

{

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



	rtnl_lock();

	tcf_exts_destroy(&f->exts);

	kfree(f);

	__fw_delete_filter(f);

	rtnl_unlock();

}
@@ -154,7 +160,10 @@ static void fw_destroy(struct tcf_proto *tp) 
			RCU_INIT_POINTER(head->ht[h],

					 rtnl_dereference(f->next));

			tcf_unbind_filter(tp, &f->res);

			if (tcf_exts_get_net(&f->exts))

				call_rcu(&f->rcu, fw_delete_filter);

			else

				__fw_delete_filter(f);

		}

	}

	kfree_rcu(head, rcu);
@@ -179,6 +188,7 @@ static int fw_delete(struct tcf_proto *tp, void *arg, bool *last) 
		if (pfp == f) {

			RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));

			tcf_unbind_filter(tp, &f->res);

			tcf_exts_get_net(&f->exts);

			call_rcu(&f->rcu, fw_delete_filter);

			ret = 0;

			break;
@@ -299,6 +309,7 @@ static int fw_change(struct net *net, struct sk_buff *in_skb, 
		RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));

		rcu_assign_pointer(*fp, fnew);

		tcf_unbind_filter(tp, &f->res);

		tcf_exts_get_net(&f->exts);

		call_rcu(&f->rcu, fw_delete_filter);



		*arg = fnew;