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Subject: Re: [Cocci] [PATCH] net: Zeroing the structure ethtool_wolinfo in
 ethtool_get_wol()
To:     Joe Perches <joe@perches.com>, zhanglin <zhang.lin16@zte.com.cn>,
        davem@davemloft.net, cocci <cocci@systeme.lip6.fr>,
        Andrew Morton <akpm@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     mkubecek@suse.cz, jakub.kicinski@netronome.com, ast@kernel.org,
        jiang.xuexin@zte.com.cn, f.fainelli@gmail.com,
        daniel@iogearbox.net, john.fastabend@gmail.com,
        lirongqing@baidu.com, maxime.chevallier@bootlin.com,
        vivien.didelot@gmail.com, dan.carpenter@oracle.com,
        wang.yi59@zte.com.cn, hawk@kernel.org, arnd@arndb.de,
        jiri@mellanox.com, xue.zhihong@zte.com.cn,
        natechancellor@gmail.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linyunsheng@huawei.com,
        pablo@netfilter.org, bpf@vger.kernel.org
References: <1572076456-12463-1-git-send-email-zhang.lin16@zte.com.cn>
 <c790578751dd69fb1080b355f5847c9ea5fb0e15.camel@perches.com>
From:   "Enrico Weigelt, metux IT consult" <lkml@metux.net>
Message-ID: <bc150c6a-6d3e-ff01-e40e-840e8a385bda@metux.net>
Date:   Thu, 21 Nov 2019 11:23:34 +0100
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On 26.10.19 21:40, Joe Perches wrote:
> On Sat, 2019-10-26 at 15:54 +0800, zhanglin wrote:
>> memset() the structure ethtool_wolinfo that has padded bytes
>> but the padded bytes have not been zeroed out.
> []
>> diff --git a/net/core/ethtool.c b/net/core/ethtool.c
> []
>> @@ -1471,11 +1471,13 @@ static int ethtool_reset(struct net_device *dev, char __user *useraddr)
>>  
>>  static int ethtool_get_wol(struct net_device *dev, char __user *useraddr)
>>  {
>> -	struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
>> +	struct ethtool_wolinfo wol;
>>  
>>  	if (!dev->ethtool_ops->get_wol)
>>  		return -EOPNOTSUPP;
>>  
>> +	memset(&wol, 0, sizeof(struct ethtool_wolinfo));
>> +	wol.cmd = ETHTOOL_GWOL;
>>  	dev->ethtool_ops->get_wol(dev, &wol);
>>  
>>  	if (copy_to_user(useraddr, &wol, sizeof(wol)))
> 
> It seems likely there are more of these.
> 
> Is there any way for coccinelle to find them?

Just curios: is static struct initialization (on stack) something that
should be avoided ? I've been under the impression that static
initialization allows thinner code and gives the compiler better chance
for optimizations.


--mtx

---
Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
info@metux.net -- +49-151-27565287