netdev - Re: [RFC PATCH] xfrm: fix handling of XFRM policies mark and mask.

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:	Fri, 8 Feb 2013 15:16:45 +0100
From:	Emmanuel Thierry <emmanuel.thierry@...ecom-bretagne.eu>
To:	Steffen Klassert <steffen.klassert@...unet.com>
Cc:	jamal <j.hadi123@...il.com>, Romain KUNTZ <r.kuntz@...lavors.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"davem@...emloft.net" <davem@...emloft.net>,
	herbert@...dor.apana.org.au,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Jamal Hadi Salim <hadi@...erus.ca>
Subject: Re: [RFC PATCH] xfrm: fix handling of XFRM policies mark and mask.

Hello,

Le 7 févr. 2013 à 13:54, Steffen Klassert <steffen.klassert@...unet.com> a écrit :

> On Thu, Feb 07, 2013 at 12:08:22PM +0100, Emmanuel Thierry wrote:
>> 
>> This is a nice idea, however you keep the insertion asymmetric. The usage of xfrm marks in non-conflicting cases will be made possible, but it stays disturbing for a user as the initial example will still have the same behavior:
>> * Inserting the marked one then the unmarked will succeed
>> * Inserting the unmarked then the marked one will fail
>> This gives to the user the feeling of an indeterministic behavior of the xfrm module.
> 
> This was intended. Inserting the marked one then the unmarked
> is a working scenario. Some users might rely on it, so we can't
> change this as you proposed.
> 
> On the other hand, inserting the unmarked one then the marked
> might result in a wrong policy lookup, so we can't allow this.
> The only possibility we have, is inserting with different
> priorites and that's what I'm proposing.
> 
> I fear we have to live with that asymmetric behaviour if
> both policies have the same priority.
> 

Ok, actually i understand the concern of backward compatibility you expose. It is true that users might be disturbed if we change such a behavior they would rely on.
Anyway, i'm ok with your patch.

Best regards
Emmanuel Thierry--
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