netdev - Re: [PATCH 1/2] Revert "xfrm: interface with if

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: <20220301161001.GV1223722@gauss3.secunet.de>
Date:   Tue, 1 Mar 2022 17:10:01 +0100
From:   Steffen Klassert <steffen.klassert@...unet.com>
To:     Kai Lüke <kailueke@...ux.microsoft.com>
CC:     Paul Chaignon <paul@...ium.io>,
        Eyal Birger <eyal.birger@...il.com>, <netdev@...r.kernel.org>
Subject: Re: [PATCH 1/2] Revert "xfrm: interface with if_id 0 should return
 error"

On Tue, Mar 01, 2022 at 04:48:38PM +0100, Kai Lüke wrote:
> > I agree with Eyal here.  As far as Cilium is concerned, this is not
> > causing any regression.  Only the second commit, 68ac0f3810e7 ("xfrm:
> > state and policy should fail if XFRMA_IF_ID 0") causes issues in a
> > previously-working setup in Cilium.  We don't use xfrm interfaces.
> >
> I see this as a very generic question of changing userspace behavior or
> not, regardless if we know how many users are affected, and from what I
> know there are similar cases in the kernel where the response was that
> breaking userspace is a no go - even if the intention was to be helpful
> by having early errors.

In general I agree that the userspace ABI has to be stable, but
this never worked. We changed the behaviour from silently broken to
notify userspace about a misconfiguration.

It is the question what is more annoying for the users. A bug that
we can never fix, or changing a broken behaviour to something that
tells you at least why it is not working.

In such a case we should gauge what's the better solution. Here
I tend to keep it as it is.