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Date:   Tue, 6 Jun 2023 13:21:12 +0200
From:   Jiri Pirko <jiri@resnulli.us>
To:     Hangyu Hua <hbh25y@gmail.com>
Cc:     jhs@mojatatu.com, xiyou.wangcong@gmail.com, davem@davemloft.net,
        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] net: sched: fix possible refcount leak in
 tc_chain_tmplt_add()
Message-ID: <ZH8WqFQZrniml8Yq@nanopsycho>
References: <20230605070158.48403-1-hbh25y@gmail.com>
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In-Reply-To: <20230605070158.48403-1-hbh25y@gmail.com>
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Mon, Jun 05, 2023 at 09:01:58AM CEST, hbh25y@gmail.com wrote:
>try_module_get can be called in tcf_proto_lookup_ops. So if ops don't
>implement the corresponding function we should call module_put to drop
>the refcount.

Who's "we"? Use imperative mood. Tell the codebase what to do, what to
change, etc.

Code-wise, this is fine. Please fix the patch description.


>
>Fixes: 9f407f1768d3 ("net: sched: introduce chain templates")
>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 2621550bfddc..92bfb892e638 100644
>--- a/net/sched/cls_api.c
>+++ b/net/sched/cls_api.c
>@@ -2952,6 +2952,7 @@ static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
> 		return PTR_ERR(ops);
> 	if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
> 		NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
>+		module_put(ops->owner);
> 		return -EOPNOTSUPP;
> 	}
> 
>-- 
>2.34.1
>