net/sched: act_tunnel_key: Remove rcu_read_lock protection (07c0f09e) · Commits · 戴 / test

Remove rcu_read_lock protection from tunnel_key_dump and use rtnl_dereference, dump operation is protected by rtnl lock. Also, remove rcu_read_lock from tunnel_key_release and use rcu_dereference_protected. Both operations are running exclusively and a writer couldn't modify t->params while those functions are executed. Fixes: 54d94fd89d90 ('net/sched: Introduce act_tunnel_key') Signed-off-by:

Hadar Hen Zion <hadarh@mellanox.com> Acked-by:

John Fastabend <john.r.fastabend@intel.com> Acked-by:

Eric Dumazet <edumazet@google.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/sched/act_tunnel_key.c

+4 −13

Original line number	Diff line number	Diff line
		@@ -194,15 +194,12 @@ static void tunnel_key_release(struct tc_action *a, int bind)
		struct tcf_tunnel_key *t = to_tunnel_key(a);
		struct tcf_tunnel_key_params *params;

		rcu_read_lock();
		params = rcu_dereference(t->params);
		params = rcu_dereference_protected(t->params, 1);

		if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET)
		dst_release(&params->tcft_enc_metadata->dst);

		kfree_rcu(params, rcu);

		rcu_read_unlock();
		}

		static int tunnel_key_dump_addresses(struct sk_buff *skb,
		@@ -245,10 +242,8 @@ static int tunnel_key_dump(struct sk_buff skb, struct tc_action a,
		.bindcnt = t->tcf_bindcnt - bind,
		};
		struct tcf_t tm;
		int ret = -1;

		rcu_read_lock();
		params = rcu_dereference(t->params);
		params = rtnl_dereference(t->params);

		opt.t_action = params->tcft_action;
		opt.action = params->action;
		@@ -272,15 +267,11 @@ static int tunnel_key_dump(struct sk_buff skb, struct tc_action a,
		&tm, TCA_TUNNEL_KEY_PAD))
		goto nla_put_failure;

		ret = skb->len;
		goto out;
		return skb->len;

		nla_put_failure:
		nlmsg_trim(skb, b);
		out:
		rcu_read_unlock();

		return ret;
		return -1;
		}

		static int tunnel_key_walker(struct net net, struct sk_buff skb,

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