From: Wang Chen <wangchen@cn.fujitsu.com>
To: "YOSHIFUJI Hideaki / 吉藤英明" <yoshfuji@linux-ipv6.org>
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: Re: [2.6 PATCH] IPV6: Check length of optval provided by user in setsockopt()
Date: Mon, 31 Mar 2008 18:46:25 +0800 [thread overview]
Message-ID: <47F0C101.9090302@cn.fujitsu.com> (raw)
In-Reply-To: <20080331.181551.118587102.yoshfuji@linux-ipv6.org>
YOSHIFUJI Hideaki / 吉藤英明 said the following on 2008-3-31 17:15:
> In article <47F0AA16.1070900@cn.fujitsu.com> (at Mon, 31 Mar 2008 17:08:38 +0800), Wang Chen <wangchen@cn.fujitsu.com> says:
>
>> Check length of setsockopt's optval, which provided by user, before copy it
>> from user space.
>
> Please use "<" not "==".
>
There are two reasons that why I only check whether
len of optval is equal to that one in user space.
1. We currently copy the entire structure from user
to kernel.
2. In other cases, such as IPV6_LEAVE/JOIN_ANYCAST,
we check whether the len is equal to struct's len.
So, Yoshifuji-san, can you tell me more about why we
should use "<"? :)
--WCN
next prev parent reply other threads:[~2008-03-31 10:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-31 9:08 [2.6 PATCH] IPV6: Check length of optval provided by user in setsockopt() Wang Chen
2008-03-31 9:15 ` YOSHIFUJI Hideaki / 吉藤英明
2008-03-31 10:46 ` Wang Chen [this message]
2008-03-31 10:53 ` YOSHIFUJI Hideaki / 吉藤英明
2008-03-31 11:04 ` Wang Chen
2008-04-07 1:42 ` Wang Chen
2008-04-11 7:15 ` YOSHIFUJI Hideaki / 吉藤英明
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