Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH] net: smc: fix error return code of smc_diag_dump_proto()
To:     Jia-Ju Bai <baijiaju1990@gmail.com>, davem@davemloft.net,
        kuba@kernel.org
Cc:     linux-s390@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20210305101351.14683-1-baijiaju1990@gmail.com>
From:   Karsten Graul <kgraul@linux.ibm.com>
Organization: IBM Deutschland Research & Development GmbH
Message-ID: <d1d50e39-e496-1060-2c71-2338c0572c55@linux.ibm.com>
Date:   Fri, 5 Mar 2021 11:30:20 +0100
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.6.1
MIME-Version: 1.0
In-Reply-To: <20210305101351.14683-1-baijiaju1990@gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 05/03/2021 11:13, Jia-Ju Bai wrote:
> When the list of head is empty, no error return code of
> smc_diag_dump_proto() is assigned.
> To fix this bug, rc is assigned with -ENOENT as error return code.

Your change would break smc_diag_dump().
When there are no IPv4 sockets (SMCPROTO_SMC) in the list and -ENOENT 
is returned then smc_diag_dump() will not try to dump any IPv6 sockets
(SMCPROTO_SMC6). Returning zero is correct here.

> 
> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
>  net/smc/smc_diag.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/net/smc/smc_diag.c b/net/smc/smc_diag.c
> index c952986a6aca..a90889482842 100644
> --- a/net/smc/smc_diag.c
> +++ b/net/smc/smc_diag.c
> @@ -201,8 +201,10 @@ static int smc_diag_dump_proto(struct proto *prot, struct sk_buff *skb,
>  
>  	read_lock(&prot->h.smc_hash->lock);
>  	head = &prot->h.smc_hash->ht;
> -	if (hlist_empty(head))
> +	if (hlist_empty(head)) {
> +		rc = -ENOENT;
>  		goto out;
> +	}
>  
>  	sk_for_each(sk, head) {
>  		if (!net_eq(sock_net(sk), net))
> 

-- 
Karsten

(I'm a dude)