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Subject: Re: [PATCH net-next] net: ipv4: use BUG_ON instead of if condition
 followed by BUG
To:     Zheng Yongjun <zhengyongjun3@huawei.com>, davem@davemloft.net,
        yoshfuji@linux-ipv6.org, dsahern@kernel.org, kuba@kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20210607091131.2766890-1-zhengyongjun3@huawei.com>
From:   David Ahern <dsahern@gmail.com>
Message-ID: <6b84747d-80a9-08d8-c4e3-c91cdaa99330@gmail.com>
Date:   Mon, 7 Jun 2021 06:59:44 -0600
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On 6/7/21 3:11 AM, Zheng Yongjun wrote:
> Use BUG_ON instead of if condition followed by BUG in inet_set_link_af.
> 
> This issue was detected with the help of Coccinelle.
> 
> Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
> ---
>  net/ipv4/devinet.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
> index 2e35f68da40a..e3e1e8a600ef 100644
> --- a/net/ipv4/devinet.c
> +++ b/net/ipv4/devinet.c
> @@ -1988,8 +1988,7 @@ static int inet_set_link_af(struct net_device *dev, const struct nlattr *nla,
>  	if (!in_dev)
>  		return -EAFNOSUPPORT;
>  
> -	if (nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla, NULL, NULL) < 0)
> -		BUG();
> +	BUG_ON(nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla, NULL, NULL) < 0);
>  
>  	if (tb[IFLA_INET_CONF]) {
>  		nla_for_each_nested(a, tb[IFLA_INET_CONF], rem)
> 

no reason to have a BUG here at all. Catch the error and return.