From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73296C433FE for ; Wed, 11 May 2022 14:36:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244773AbiEKOgc (ORCPT ); Wed, 11 May 2022 10:36:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243006AbiEKOg2 (ORCPT ); Wed, 11 May 2022 10:36:28 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3AB32DD40 for ; Wed, 11 May 2022 07:36:27 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nonRu-0002Lv-Bs; Wed, 11 May 2022 16:36:22 +0200 Received: from pengutronix.de (unknown [IPv6:2a01:4f8:1c1c:29e9:22:41ff:fe00:1400]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mkl-all@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id D8B317BDD4; Wed, 11 May 2022 14:36:20 +0000 (UTC) Date: Wed, 11 May 2022 16:36:20 +0200 From: Marc Kleine-Budde To: Oliver Hartkopp Cc: Oleksij Rempel , Wolfgang Grandegger , Devid Antonio Filoni , kernel@pengutronix.de, linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, David Jander Subject: Re: [PATCH 1/1] can: skb: add and set local_origin flag Message-ID: <20220511143620.kphwgp2vhjyoecs5@pengutronix.de> References: <20220511121913.2696181-1-o.rempel@pengutronix.de> <20220511132421.7o5a3po32l3w2wcr@pengutronix.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="ljoxgzahuknnbyf5" Content-Disposition: inline In-Reply-To: <20220511132421.7o5a3po32l3w2wcr@pengutronix.de> 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --ljoxgzahuknnbyf5 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 11.05.2022 15:24:21, Marc Kleine-Budde wrote: > On 11.05.2022 14:38:32, Oliver Hartkopp wrote: > > IMO this patch does not work as intended. > >=20 > > You probably need to revisit every place where can_skb_reserve() is use= d, > > e.g. in raw_sendmsg(). >=20 > And the loopback for devices that don't support IFF_ECHO: >=20 > | https://elixir.bootlin.com/linux/latest/source/net/can/af_can.c#L257 BTW: There is a bug with interfaces that don't support IFF_ECHO. Assume an invalid CAN frame is passed to can_send() on an interface that doesn't support IFF_ECHO. The above mentioned code does happily generate an echo frame and it's send, even if the driver drops it, due to can_dropped_invalid_skb(dev, skb). The echoed back CAN frame is treated in raw_rcv() as if the headroom is val= id: | https://elixir.bootlin.com/linux/v5.17.6/source/net/can/raw.c#L138 But as far as I can see the can_skb_headroom_valid() check never has been done. What about this patch? index 1fb49d51b25d..fda4807ad165 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -255,6 +255,9 @@ int can_send(struct sk_buff *skb, int loop) */ =20 if (!(skb->dev->flags & IFF_ECHO)) { + if (can_dropped_invalid_skb(dev, skb)) + return -EINVAL; + /* If the interface is not capable to do loopback * itself, we do it here. */ Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | --ljoxgzahuknnbyf5 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEBsvAIBsPu6mG7thcrX5LkNig010FAmJ7yeEACgkQrX5LkNig 013sQgf9GZiV+J8h1BBY78BuX+q12pFS6uA1Ocl8Xx+dHF//nkU2y9FuYXbn8+fi fBFXw7jdhwMMfjSQPLHCbTXbLdrwEONAkQ1QQ6Db5M450W/8wisOgf+JqjDNM3iU tvZ1x3l3U/xFkFTdCm2A3IE/UMG7kaxeb/5v3Fk283gZNZ6FBhymRrxxofTfUtRJ G9Mn3Bhge8BFZ84kJZcYqhbAspY4MWoDKRDSysEjt0hxq37TxJw4M0JL4cPVH6s/ 8/HjzP5MZBh4Ep+dp4g5Y/KjEoLTLvbCtVHXcnJaLYJwW0vDvAKMG6dA8dQnc8fl 9gmOJe5ZtenWSw87iMOsTEekkDFy2A== =sDfU -----END PGP SIGNATURE----- --ljoxgzahuknnbyf5--