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Date:   Tue, 20 Sep 2022 08:50:06 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Hangyu Hua <hbh25y@gmail.com>
Cc:     jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us,
        davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
        vladbu@mellanox.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: sched: fix possible refcount leak in
 tc_new_tfilter()
Message-ID: <20220920085006.32c743be@kernel.org>
In-Reply-To: <20220915085804.20894-1-hbh25y@gmail.com>
References: <20220915085804.20894-1-hbh25y@gmail.com>
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On Thu, 15 Sep 2022 16:58:04 +0800 Hangyu Hua wrote:
> tfilter_put need to be called to put the refount got by tp->ops->get to

s/refount/refcount/

> avoid possible refcount leak when chain->tmplt_ops == NULL or
> chain->tmplt_ops != tp->ops.

This should say:

  when cain->tmplt_ops != NULL and ...

otherwise the commit message does not match the code.

> Fixes: 7d5509fa0d3d ("net: sched: extend proto ops with 'put' callback")
> Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
> ---
>  net/sched/cls_api.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
> index 790d6809be81..51d175f3fbcb 100644
> --- a/net/sched/cls_api.c
> +++ b/net/sched/cls_api.c
> @@ -2137,6 +2137,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
>  	}
>  
>  	if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
> +		tfilter_put(tp, fh);
>  		NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
>  		err = -EINVAL;
>  		goto errout;