[Patch net] net_sched: remove a redundant goto chain check

[Patch net] net_sched: remove a redundant goto chain check

[Cong Wang]

All TC actions call tcf_action_check_ctrlact() to validate
goto chain, so this check in tcf_action_init_1() is actually
redundant. Remove it to save troubles of leaking memory.

Fixes: e49d8c22f126 ("net_sched: defer tcf_idr_insert() in tcf_action_init_1()")
Reported-by: Vlad Buslov <vladbu@mellanox.com>
Suggested-by: Davide Caratti <dcaratti@redhat.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/act_api.c | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 104b47f5184f..5612b336e18e 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -722,13 +722,6 @@ int tcf_action_destroy(struct tc_action *actions[], int bind)
 	return ret;
 }
 
-static int tcf_action_destroy_1(struct tc_action *a, int bind)
-{
-	struct tc_action *actions[] = { a, NULL };
-
-	return tcf_action_destroy(actions, bind);
-}
-
 static int tcf_action_put(struct tc_action *p)
 {
 	return __tcf_action_put(p, false);
@@ -1000,13 +993,6 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 	if (err < 0)
 		goto err_mod;
 
-	if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
-	    !rcu_access_pointer(a->goto_chain)) {
-		tcf_action_destroy_1(a, bind);
-		NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
-		return ERR_PTR(-EINVAL);
-	}
-
 	if (!name && tb[TCA_ACT_COOKIE])
 		tcf_set_action_cookie(&a->act_cookie, cookie);
 
-- 
2.28.0

Re: [Patch net] net_sched: remove a redundant goto chain check

[Davide Caratti]

On Mon, 2020-09-28 at 11:31 -0700, Cong Wang wrote:
> All TC actions call tcf_action_check_ctrlact() to validate
> goto chain, so this check in tcf_action_init_1() is actually
> redundant. Remove it to save troubles of leaking memory.
> 
> Fixes: e49d8c22f126 ("net_sched: defer tcf_idr_insert() in tcf_action_init_1()")
> Reported-by: Vlad Buslov <vladbu@mellanox.com>
> Suggested-by: Davide Caratti <dcaratti@redhat.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/act_api.c | 14 --------------
>  1 file changed, 14 deletions(-)
> 
> diff --git a/net/sched/act_api.c b/net/sched/act_api.c
> index 104b47f5184f..5612b336e18e 100644
> --- a/net/sched/act_api.c
> +++ b/net/sched/act_api.c
> @@ -722,13 +722,6 @@ int tcf_action_destroy(struct tc_action *actions[], int bind)
>  	return ret;
>  }
>  
> -static int tcf_action_destroy_1(struct tc_action *a, int bind)
> -{
> -	struct tc_action *actions[] = { a, NULL };
> -
> -	return tcf_action_destroy(actions, bind);
> -}
> -
>  static int tcf_action_put(struct tc_action *p)
>  {
>  	return __tcf_action_put(p, false);
> @@ -1000,13 +993,6 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
>  	if (err < 0)
>  		goto err_mod;
>  
> -	if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
> -	    !rcu_access_pointer(a->goto_chain)) {
> -		tcf_action_destroy_1(a, bind);
> -		NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
> -		return ERR_PTR(-EINVAL);
> -	}
> -
>  	if (!name && tb[TCA_ACT_COOKIE])
>  		tcf_set_action_cookie(&a->act_cookie, cookie);
>  

Reviewed-by: Davide Caratti <dcaratti@redhat.com>

thanks!
-- 
davide

Re: [Patch net] net_sched: remove a redundant goto chain check

[David Miller]

From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Mon, 28 Sep 2020 11:31:03 -0700

> All TC actions call tcf_action_check_ctrlact() to validate
> goto chain, so this check in tcf_action_init_1() is actually
> redundant. Remove it to save troubles of leaking memory.
> 
> Fixes: e49d8c22f126 ("net_sched: defer tcf_idr_insert() in tcf_action_init_1()")
> Reported-by: Vlad Buslov <vladbu@mellanox.com>
> Suggested-by: Davide Caratti <dcaratti@redhat.com>
> Cc: Jamal Hadi Salim <jhs@mojatatu.com>
> Cc: Jiri Pirko <jiri@resnulli.us>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>

Applied, thank you.