From 07c0f09e23b47815251ed9e5ce245a58c6391974 Mon Sep 17 00:00:00 2001 From: Hadar Hen Zion Date: Mon, 12 Sep 2016 15:19:21 +0300 Subject: [PATCH] net/sched: act_tunnel_key: Remove rcu_read_lock protection 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 Acked-by: John Fastabend Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/act_tunnel_key.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c index dceff7412dc3..af47bdf2f483 100644 --- a/net/sched/act_tunnel_key.c +++ b/net/sched/act_tunnel_key.c @@ -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(¶ms->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, -- 2.11.0