From mboxrd@z Thu Jan  1 00:00:00 1970
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH v2] serial: max310x: Fix out of bounds access
Date: Wed, 12 Aug 2015 08:17:07 -0700
Message-ID: <20150812151707.GB12397@kroah.com>
References: <1439364125-19422-1-git-send-email-cantona@cantona.net>
 <CABJLtPHPCw7VN+wG4ApDxB-ZM7wRz_1xHfpNLL4o4_80JYyKaQ@mail.gmail.com>
 <1439372765.705411926@f362.i.mail.ru>
 <CABJLtPG7gfR8VSVfzRgF8XgON7F-mhfMu7C2an0sfQYLBNiLpg@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: QUOTED-PRINTABLE
Return-path: <linux-kernel-owner@vger.kernel.org>
Content-Disposition: inline
In-Reply-To: <CABJLtPG7gfR8VSVfzRgF8XgON7F-mhfMu7C2an0sfQYLBNiLpg@mail.gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
To: Kang Yin Su <cantona@cantona.net>
Cc: Alexander Shiyan <shc_work@mail.ru>, Jiri Slaby <jslaby@suse.com>, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
List-Id: linux-serial@vger.kernel.org

On Wed, Aug 12, 2015 at 07:50:25PM +0800, Kang Yin Su wrote:
> On 12 August 2015 at 17:46, Alexander Shiyan <shc_work@mail.ru> wrote=
:
> >> =D0=A1=D1=80=D0=B5=D0=B4=D0=B0, 12 =D0=B0=D0=B2=D0=B3=D1=83=D1=81=D1=
=82=D0=B0 2015, 15:36 +08:00 =D0=BE=D1=82 cantona <cantona@cantona.net>=
:
> >>
> >>
> >> added Alexander Shiyan < shc_work@mail.ru >.
> >>
> >> On 12 August 2015 at 15:22, Su Kang Yin  < cantona@cantona.net > w=
rote:
> >> >Max310x driver supports up to 4 UART devices but array size of
> >> >"struct max310x_one" is set to 1. That leads to out of bounds
> >> >access on UART port registration.
> >> >
> >> >This patch fixed it by increase the array size to 4 which is
> >> >maximum supported UART.
> >> >
> >> >Signed-off-by: Su Kang Yin < cantona@cantona.net >
> >> >---
> > ...
> >
> > This seems incorrect. The number of ports is allocated dynamically =
by:
> > ...
> > /* Alloc port structure */
> > s =3D devm_kzalloc(dev, sizeof(*s) + sizeof(struct max310x_one) * d=
evtype->nr, GFP_KERNEL);
> > ...
> >
> > Thanks.
> >
> > ---
> >
>=20
>=20
> Oh, my bad.  But it looks confusing. So we must ensure "struct
> max310x_one p[0]"  must the last element of "struct max310x_port".

Yes, that is a very common pattern we use in the kernel.