Re: [PATCH net v2] net: sched: act_ct: fix possible refcount leak in tcf_ct_init()

From: Cong Wang <xiyou.wangcong@gmail.com>
To: Hangyu Hua <hbh25y@gmail.com>
Cc: jhs@mojatatu.com, jiri@resnulli.us, davem@davemloft.net,
	edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
	paulb@mellanox.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH net v2] net: sched: act_ct: fix possible refcount leak in tcf_ct_init()
Date: Sat, 1 Oct 2022 12:55:37 -0700	[thread overview]
Message-ID: <YzibOQ2dviUNneAY@pop-os.localdomain> (raw)
In-Reply-To: <20220923020046.8021-1-hbh25y@gmail.com>

On Fri, Sep 23, 2022 at 10:00:46AM +0800, Hangyu Hua wrote:
> nf_ct_put need to be called to put the refcount got by tcf_ct_fill_params
> to avoid possible refcount leak when tcf_ct_flow_table_get fails.
> 
> Fixes: c34b961a2492 ("net/sched: act_ct: Create nf flow table per zone")
> Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
> ---
> 
> v2: use a new label to put the refcount.
> 
>  net/sched/act_ct.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
> index d55afb8d14be..5950974ae8f6 100644
> --- a/net/sched/act_ct.c
> +++ b/net/sched/act_ct.c
> @@ -1394,7 +1394,7 @@ static int tcf_ct_init(struct net *net, struct nlattr *nla,
>  
>  	err = tcf_ct_flow_table_get(net, params);
>  	if (err)
> -		goto cleanup;
> +		goto cleanup_params;
>  
>  	spin_lock_bh(&c->tcf_lock);
>  	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
> @@ -1409,6 +1409,9 @@ static int tcf_ct_init(struct net *net, struct nlattr *nla,
>  
>  	return res;
>  
> +cleanup_params:
> +	if (params->tmpl)
> +		nf_ct_put(params->tmpl);

Nit: this NULL check is unnecessary.

Thanks.