Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751500AbcLEKz6 (ORCPT ); Mon, 5 Dec 2016 05:55:58 -0500 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:37455 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750855AbcLEKzz (ORCPT ); Mon, 5 Dec 2016 05:55:55 -0500 Subject: Re: net/can: warning in raw_setsockopt/__alloc_pages_slowpath To: Oliver Hartkopp , Andrey Konovalov , "David S. Miller" , linux-can@vger.kernel.org, netdev , LKML References:

<73b78023-bc11-25c0-33e3-3a748dbc81cd@hartkopp.net> <74e2aed8-ba38-ee91-59a3-49131ea18d60@pengutronix.de> <6fe05efd-eb2c-a5e2-9d45-48f2c3098abb@hartkopp.net> Cc: Dmitry Vyukov , Kostya Serebryany , syzkaller From: Marc Kleine-Budde Message-ID: <1d643f72-d90a-ab39-a23c-844766c10749@pengutronix.de> Date: Mon, 5 Dec 2016 11:55:45 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.4.0 MIME-Version: 1.0 In-Reply-To: <6fe05efd-eb2c-a5e2-9d45-48f2c3098abb@hartkopp.net> Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="lpn3P6fO2KhAuQvsCO2IPwVO5LjnXiJvV" X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3875 Lines: 116 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --lpn3P6fO2KhAuQvsCO2IPwVO5LjnXiJvV Content-Type: multipart/mixed; boundary="qBikJLJmAmUdFF4KjOcAvTKTSVRtE7FBk"; protected-headers="v1" From: Marc Kleine-Budde To: Oliver Hartkopp , Andrey Konovalov , "David S. Miller" , linux-can@vger.kernel.org, netdev , LKML Cc: Dmitry Vyukov , Kostya Serebryany , syzkaller Message-ID: <1d643f72-d90a-ab39-a23c-844766c10749@pengutronix.de> Subject: Re: net/can: warning in raw_setsockopt/__alloc_pages_slowpath References:

<73b78023-bc11-25c0-33e3-3a748dbc81cd@hartkopp.net> <74e2aed8-ba38-ee91-59a3-49131ea18d60@pengutronix.de> <6fe05efd-eb2c-a5e2-9d45-48f2c3098abb@hartkopp.net> In-Reply-To: <6fe05efd-eb2c-a5e2-9d45-48f2c3098abb@hartkopp.net> --qBikJLJmAmUdFF4KjOcAvTKTSVRtE7FBk Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 12/02/2016 06:05 PM, Oliver Hartkopp wrote: >=20 >=20 > On 12/02/2016 04:42 PM, Marc Kleine-Budde wrote: >> On 12/02/2016 04:11 PM, Oliver Hartkopp wrote: >>> >>> >>> On 12/02/2016 02:24 PM, Marc Kleine-Budde wrote: >>>> On 12/02/2016 01:43 PM, Andrey Konovalov wrote: >>> >>> >>>>> [] raw_setsockopt+0x1be/0x9f0 net/can/raw.c:506 >>>> >>>> We should add a check for a sensible optlen.... >>>> >>>>> static int raw_setsockopt(struct socket *sock, int level, int optna= me, >>>>> char __user *optval, unsigned int optlen) >>>>> { >>>>> struct sock *sk =3D sock->sk; >>>>> struct raw_sock *ro =3D raw_sk(sk); >>>>> struct can_filter *filter =3D NULL; /* dyn. alloc'ed filters */ >>>>> struct can_filter sfilter; /* single filter */ >>>>> struct net_device *dev =3D NULL; >>>>> can_err_mask_t err_mask =3D 0; >>>>> int count =3D 0; >>>>> int err =3D 0; >>>>> >>>>> if (level !=3D SOL_CAN_RAW) >>>>> return -EINVAL; >>>>> >>>>> switch (optname) { >>>>> >>>>> case CAN_RAW_FILTER: >>>>> if (optlen % sizeof(struct can_filter) !=3D 0) >>>>> return -EINVAL; >>>> >>>> here... >>>> >>>> if (optlen > 64 * sizeof(struct can_filter)) >>>> return -EINVAL; >>>> >>> >>> Agreed. >>> >>> But what is sensible here? >>> 64 filters is way to small IMO. >>> >>> When thinking about picking a bunch of single CAN IDs I would tend to= >>> something like 512 filters. >> >> Ok - 64 was just an arbitrary chosen value for demonstration purposes = :) >> >=20 > :-) >=20 > Would you like to send a patch? Yes, how many Filters? 512? Can you test, as I don't have the setup ready= ? Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --qBikJLJmAmUdFF4KjOcAvTKTSVRtE7FBk-- --lpn3P6fO2KhAuQvsCO2IPwVO5LjnXiJvV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEES2FAuYbJvAGobdVQPTuqJaypJWoFAlhFR7EACgkQPTuqJayp JWq8dQf+PDkoyNL5m6WBE76ojPnKNkhSS8gNvxysN0zCLe+xv52A1pAxVF0jIuFq NbF3vyXkNrX0UwSHWS/p76o4noan+49h+XFWmsGFckdrX+94lGahEIWqSpPklbAm hUnsU3uIvpgV9cn7CstMAx/68KSAo9Ffq82bfk84ALU+KqB0vBTgRjQQFU5fYfqs HCcI1AmHSWYg/jBPKsJA5jlgIn6e+KfH78yWKLFfpyDcBojkux2K91Pn76kTkdpN JHnPf4iqZU/pmqF95U7GcEt8RK0I7m3dLx6k1cQRscN7JCJX3XPZeeHFrZQ1aNhQ 2X2/je0q4kg3UB0+vMfDnCtv9MBxGQ== =OECu -----END PGP SIGNATURE----- --lpn3P6fO2KhAuQvsCO2IPwVO5LjnXiJvV--