netdev - Re: [2.6 PATCH] IPV6: Check length of optval provided by user in setsockopt()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20080331.195323.83430743.yoshfuji@linux-ipv6.org>
Date:	Mon, 31 Mar 2008 19:53:23 +0900 (JST)
From:	YOSHIFUJI Hideaki / 吉藤英明 
	<yoshfuji@...ux-ipv6.org>
To:	wangchen@...fujitsu.com
Cc:	davem@...emloft.net, netdev@...r.kernel.org,
	yoshfuji@...ux-ipv6.org
Subject: Re: [2.6 PATCH] IPV6: Check length of optval provided by user in
 setsockopt()

In article <47F0C101.9090302@...fujitsu.com> (at Mon, 31 Mar 2008 18:46:25 +0800), Wang Chen <wangchen@...fujitsu.com> says:

> YOSHIFUJI Hideaki / 吉藤英明 said the following on 2008-3-31 17:15:
> > In article <47F0AA16.1070900@...fujitsu.com> (at Mon, 31 Mar 2008 17:08:38 +0800), Wang Chen <wangchen@...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 "<"? :)

POSIX, as we have some comments in that file ;-).
If it is shorter than expected, -EINVAL, otherwise, no error.
We need to fix other sites as well.

--yoshfuji
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html