netdev - Re: [PATCHv3, ipsec-next] xfrm: Do not parse 32bits compiled xfrm netlink msg on 64bits host

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]

Date:	Mon, 02 Feb 2015 11:45:25 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	nicolas.dichtel@...nd.com
Cc:	steffen.klassert@...unet.com, fan.du@...el.com,
	herbert@...dor.apana.org.au, netdev@...r.kernel.org,
	fengyuleidian0615@...il.com
Subject: Re: [PATCHv3, ipsec-next] xfrm: Do not parse 32bits compiled xfrm
 netlink msg on 64bits host

From: Nicolas Dichtel <nicolas.dichtel@...nd.com>
Date: Mon, 02 Feb 2015 10:02:50 +0100

> Le 02/02/2015 09:44, Steffen Klassert a écrit :
>> On Thu, Jan 29, 2015 at 11:29:51AM +0100, Nicolas Dichtel wrote:
> [snip]
>>>
>>> The point I try to make is that patching userland apps allows to use
>>> xfrm on a
>>> 32bits userland / 64bits kernel.
>>
>> Ugh, I did not know that this is used that way. Which applications do
>> this?
>> So the situation is worse than I thought. What happens to such
>> applications
>> if we add a compat layer in the kernel? I'd guess they will break,
>> right?
>
> A compat layer will be perfect. I just wanted to highlight the fact
> that without this patch, it's possible to have a workaround to use
> netlink-xfrm and after it, it will be impossible.

Just a little history, there was a case where we tried to work around this
in userspace by messing with the structure definitions when building
the userland binaries, and that completely exploded.  This was with
the wireless extensions about 15 years ago.

If you work around it in userspace, then you can't fix the kernel to
do the right thing without potentially breaking things again for
the work around binaries that have been created.
--
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