From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S934107AbcI3Qik (ORCPT <rfc822;w@1wt.eu>);
        Fri, 30 Sep 2016 12:38:40 -0400
Received: from mout.kundenserver.de ([212.227.126.131]:53815 "EHLO
        mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S932988AbcI3Qic (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Fri, 30 Sep 2016 12:38:32 -0400
From: Arnd Bergmann <arnd@arndb.de>
To: Eric Dumazet <edumazet@google.com>
Subject: Re: [PATCH] net: rtnl: avoid uninitialized data in IFLA_VF_VLAN_LIST handling
Date: Fri, 30 Sep 2016 18:38:05 +0200
User-Agent: KMail/1.12.2 (Linux/4.7.0-rc7+; KDE/4.3.2; x86_64; ; )
Cc: "David S. Miller" <davem@davemloft.net>,
        Roopa Prabhu <roopa@cumulusnetworks.com>,
        Nicolas Dichtel <nicolas.dichtel@6wind.com>,
        Nikolay Aleksandrov <nikolay@cumulusnetworks.com>,
        Jiri Pirko <jiri@mellanox.com>, Brenden Blanco <bblanco@plumgrid.com>,
        Hannes Frederic Sowa <hannes@stressinduktion.org>,
        Nogah Frankel <nogahf@mellanox.com>, netdev <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Moshe Shemesh <moshe@mellanox.com>, Tariq Toukan <tariqt@mellanox.com>
References: <20160930161416.18660-1-arnd@arndb.de> <CANn89iK2FQufz4NCan1y0dQME2RUOzc3NXXhqYd418ctHNc6fA@mail.gmail.com>
In-Reply-To: <CANn89iK2FQufz4NCan1y0dQME2RUOzc3NXXhqYd418ctHNc6fA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="utf-8"
Content-Transfer-Encoding: 7bit
Message-Id: <201609301838.05349.arnd@arndb.de>
X-Provags-ID: V03:K0:m1WlzQDHd1Z4cNYGcdUX1r8wIlOCrcpAlx2ZILMN2tu8vOUdHYo
 J3qqVQimvpfGV2iAtQrEHOtwvZlbeUKkP3jzfJ3vuf85rNfzbKi2S1Fja8GB7s7ozWheDUf
 P7TTjUM5RyMmh+bA1hFxrizbhVY+dNdIMIQoccZtgQCiyQn8PihNw37lauZmH6u8+AIswL1
 DPibcnHdvYu/f8SCyqb5A==
X-UI-Out-Filterresults: notjunk:1;V01:K0:lzqH+opJBPQ=:Njp8uOA10MvspScx3bZrOp
 7Pw0tsj+9+Uerm4qQkof3mXqg5wuBvDYlah9l5xHJPAz6qICddFSNosYQ7zcQH2KBA2BGPfuU
 gTqdyo2qSpffgz9C4L8Vz+wWQ6T/t46SsPeaDlTpakC/xPQCOaD1gzaVC5/AtBm4DRRD/RGDj
 24lE/DjeVrTNE0yWfjLHzxVbPWaJKpIta/5Kvw7dPwVUuXTBNMH9ZJKM9UCiKPUPfO1IUvSX9
 NgwH9x98Dk5Ty08XXpG4XN5YsyxrDRqlBI7NIv6ZPXKVqX60kPZKNMOsUXjN3MEURpTXeM7Oe
 0B+Gm8BLRM1ee65gk4x7MPRAwdFXsvJeG6ljXFrwoAa/vR70QFAuVBbnxgS+g8DTLici11bqn
 JWaFoDlKwqLNHN2TSd7DxMENGmTEszN2lAfV3Zw4VLxX+b9u3eq6vZO3Dn4CF3D3yllU5mjrV
 DTg3g5kfpfEd9oEvRcyC7AufvSCdzM4lxTvcz5YEcnItyIYuBC0F9nDTzeCWYOLA01loNgEfE
 WyAF5Aq8hJ1kpqat4UfPW8o1ZzCoDjnrgetUAPHnDxCjTPOJ+OsU1HDJE71cVjKcopg+kqf4m
 s+4NFxTLrY41+LOsGZPCcqBPL/hIadNZZqZv+xANFMxP/G0kX10w6otKkifWQM+SCBSoLzqPP
 ewi3Gsma+OSqV5hp5pLeQ6Gu60rGWL1aMNzwxAmDe0mSnkSnrZ8uyH2Cs0/DKYPFly1vAkNfe
 bsobf0zvJs4skIws
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Friday 30 September 2016, Eric Dumazet wrote:
> > @@ -1753,6 +1753,9 @@ static int do_setvfinfo(struct net_device *dev, struct nlattr **tb)
> >
> >                         len++;
> >                 }
> > +               if (len == 0)
> > +                       return -EINVAL;
> > +
> >                 err = ops->ndo_set_vf_vlan(dev, ivvl[0]->vf, ivvl[0]->vlan,
> >                                            ivvl[0]->qos, ivvl[0]->vlan_proto);
> >                 if (err < 0)
> > --
> > 2.9.0
> >
> 
> So, if I read this code, we build an array, but call ndo_set_vf_vlan()
> only using first element ?
> 
> Looks like the bug should be fixed in a different way.

I was wondering about this too, but didn't understand enough about it to say
if it was intentional or not. I just realized that I forgot to add Moshe and Tariq
on Cc (I relied on scripts/get_maintainer.pl, but didn't double-check).
I've added them to Cc now, hope they can clarify this.

	Arnd