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 X-Spam-Level: X-Spam-Status: No, score=-14.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,PDS_BAD_THREAD_QP_64,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA221C433B4 for ; Fri, 9 Apr 2021 12:56:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78579610FC for ; Fri, 9 Apr 2021 12:56:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233705AbhDIM4N (ORCPT ); Fri, 9 Apr 2021 08:56:13 -0400 Received: from mail-vi1eur05on2067.outbound.protection.outlook.com ([40.107.21.67]:25664 "EHLO EUR05-VI1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S233529AbhDIM4L (ORCPT ); Fri, 9 Apr 2021 08:56:11 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=jy+b17DhyeoUeqZsuQO9Hza/GugaEfYVHK4CsfC20Hitpdrk8FPapl8NR+S9Gx5kM0PGiDlbTv8wdflC99mCp17YG4qjIKucm7HR1apO6P5B4ULG/roRVOKD20IHWtjREFc4eCmmM00kWqnEQdXp6KDXUidgvKNQPef4nnVeHpldtogGPofbs2U9BQ0ALSAuwRK+vdqXdvpMITyrYGav7ORNvC5AKtDIcyPGNJZmBd4XeKwZA2XHovvj1K/NErK2ik8yAeYXgfqGcBjLYpX6s3eKNIYhhgswEAbWt5xEcFo53pHtIPXmLu3GzplZp1x8O9qWH+rHPlFcw/qRz9IbJA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=8AjZAQvmJWndFgx9gh2V/ujtolqd2dBV1W0Bmt2K8aM=; b=NTgs8sonIAvXRCe4dHK2A4h2q7ZkgA15SmyCaNP4kFJW7pVIi+S4Z0ujXm/S15R61o8/R3hBVq7KgBTfOAmBp4nVr1vfKnQolw0ASDJRqL+yUZcW11QXcmJ9I/p4CWKhKwBNGg/gEtdbMGe+m/KjKDqocJB4CY4xUcES3wai5n1jVMwKLPv1m4mpIrCMCKwCqBd3gbMcj9iQZ0XkHukb9lX7+ihB6+n1lVm/1ZvimAPDk8zgxXS/BcsuJAPvvhZOkNL03qxnr8z+26if3tcvWvCPxHSZ0nP1PZLjhAu7wIFziU2K3lLAT6xe0ucq32dwp3LjCxLxXYjejH5EnO2Yig== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nxp.com; dmarc=pass action=none header.from=nxp.com; dkim=pass header.d=nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nxp.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=8AjZAQvmJWndFgx9gh2V/ujtolqd2dBV1W0Bmt2K8aM=; b=TUlvFA6D2T5mi7B6e1dZuar4BeQsgR/zTraGgWN5F8iqHmmRS4DOZFdAqaOLHpBAVlbdH+ioLNGdig0AUNAcQCxbKYhfGdyat3EUkG2zVKkTABi+CXuWkBXNJCYWBqycuJU1S2AUlVLUX/obpgnuBG8eEsIUjG26TYIsVYcZH1A= Received: from VI1PR04MB5136.eurprd04.prod.outlook.com (2603:10a6:803:55::19) by VI1PR0401MB2512.eurprd04.prod.outlook.com (2603:10a6:800:4e::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3999.29; Fri, 9 Apr 2021 12:55:56 +0000 Received: from VI1PR04MB5136.eurprd04.prod.outlook.com ([fe80::f0c0:cb99:d153:e39b]) by VI1PR04MB5136.eurprd04.prod.outlook.com ([fe80::f0c0:cb99:d153:e39b%7]) with mapi id 15.20.3999.035; Fri, 9 Apr 2021 12:55:56 +0000 From: Vladimir Oltean To: Dan Carpenter CC: Claudiu Manoil , "David S. Miller" , Jakub Kicinski , "netdev@vger.kernel.org" , "kernel-janitors@vger.kernel.org" Subject: Re: [PATCH net-next] net: enetc: fix array underflow in error handling code Thread-Topic: [PATCH net-next] net: enetc: fix array underflow in error handling code Thread-Index: AQHXLTtXmPeOqt98/E+iT6tZsxw7w6qsJOMA Date: Fri, 9 Apr 2021 12:55:55 +0000 Message-ID: <20210409125554.vevm473y4oq2rjjq@skbuf> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: oracle.com; dkim=none (message not signed) header.d=none;oracle.com; dmarc=none action=none header.from=nxp.com; x-originating-ip: [5.12.16.165] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: b977c6c0-21a0-4f8d-5896-08d8fb56d11b x-ms-traffictypediagnostic: VI1PR0401MB2512: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:8882; x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 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 x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VI1PR04MB5136.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(7916004)(39860400002)(136003)(366004)(396003)(376002)(346002)(6506007)(86362001)(91956017)(6486002)(9686003)(76116006)(1076003)(478600001)(66446008)(66556008)(66946007)(64756008)(66476007)(54906003)(83380400001)(186003)(8936002)(4326008)(26005)(316002)(33716001)(38100700001)(44832011)(6512007)(71200400001)(8676002)(2906002)(5660300002)(6916009);DIR:OUT;SFP:1101; x-ms-exchange-antispam-messagedata: =?us-ascii?Q?AZMug0nuAmSc/s/BQLdC5ferxzZqxklTx9dcppR5xmy1NyNc6U/DeW0C0BCs?= =?us-ascii?Q?zELhNrjLh7sKRCRNEWJW6JfjA7m+xM7iDgXJ8cR6qSvpu7DoZbpuVUO6+WwZ?= =?us-ascii?Q?MYlEn9fVZhBOJ7olKwM/va2C2VxoJfVHbZzkdi8we8uettSkwDKYswYih0Wh?= =?us-ascii?Q?5+uzl0rrW1WyTfx+CfERyLNEV9jU0qu6lMzFNq7qKbGVjRM28dSGHEi7Dboc?= =?us-ascii?Q?AeMMlHkk240ga/zny1cenVmnT/c0k54yaO+tXP3nWidTAEgQjN920E8yp9yX?= =?us-ascii?Q?jusk9N3qNrMiQoHfqLDp3ikn5IsBcv9CFMrQYdTtt/APgayS7xdr+wPxyCp6?= =?us-ascii?Q?lURuv5W6YMgSXI3boHeE2uBY3hrPOhXML5GawUqt5kGcH1mCiOzntuftNspL?= =?us-ascii?Q?26Vc9+E99M2RAR0k+mq4X63/e/tCvzlCMkfhr2eO47tvc9qb/7NZ/xxUcWxc?= =?us-ascii?Q?DpvRXbrC7/lXJB8Ji4cbhY909hzjy5Qd47pbX9Ll7zX4/ZlkhDqTM2dzNcTi?= =?us-ascii?Q?/W6NcTXNc3NUHTNd8RYeNWr9KvIboZoPgNg/ZJNI1qLz8OCXzK7VjoZiugB3?= =?us-ascii?Q?cO8lpRQAHL5VFhoH4J9aldheAmvlGtdG4XwDpLDCgfJarPG7cxvYd9QvKD1L?= =?us-ascii?Q?b+tiFNI8NjSdC9WmAGo9CrfNS0W9yLRkLhFpnvK5H0z9QIMQ1Nl9BLParqxT?= =?us-ascii?Q?uVkzn6/C7EBv+E0oSe0esmo0niYwRy3EMpJsrU39ZSPptSz295HbhtQh0h1Y?= =?us-ascii?Q?OOeAfTau2tvvjIuleHaWbLp/6oAt9T+3ktCcutqAOc4VKlcG+czaSTG18jL3?= =?us-ascii?Q?tSFAlldqCiPNdoh6Bb/k5COTRYY0DUShRNcOkdqBZO3gdRGphKjS9sd+6oV0?= =?us-ascii?Q?NgisBbIBBdu3wga7B4f3KUETFmbAEGzUZJxS6vhTxCTjGp/DtOHQgJjHTwFl?= =?us-ascii?Q?Ga4/oToRITJn6LVn7G18zBclDJ2U9brskA/Q5oXf/yr73B0U2ms8Dj8Q/G9+?= =?us-ascii?Q?a8AfhKImE859cv8EZGfHNmLM1LjEmFFJlBDRSHlt13xGK/JtsDhnQIkSz37Z?= =?us-ascii?Q?CSHWea6uFl3SZO/5mF/6oAfntvwjPsKeZxWZtXy7fNJukLPOMuupzfxo/dnK?= =?us-ascii?Q?jfepg5FPDpd77QRT+qp9098/uwCV9XcE9vNwyg/+EMNcDnlTkoJfhycVdNSk?= =?us-ascii?Q?WhgnZZ1Dhp1Uq2Ss6haMVYkR0hlGJCnWtk8a5/Av7sK/B02QH423BFSYLuiw?= =?us-ascii?Q?Cw7oVIpVo/UgzMlcPmoMAvGTtIFLtqsC+BHZvBWUB+6IyzSAdRFSGbFOzXgm?= =?us-ascii?Q?hCmKNrgQ/yZz3iSbGt/qQVa7?= Content-Type: text/plain; charset="us-ascii" Content-ID: <3B4386B500C535468CA8A92EC6603789@eurprd04.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB5136.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: b977c6c0-21a0-4f8d-5896-08d8fb56d11b X-MS-Exchange-CrossTenant-originalarrivaltime: 09 Apr 2021 12:55:56.2257 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 9cgSal0X+GKmHAc7ATmljg7ykDHHk8dRi867i/yMj+02liWrV+zsfwD0/Le2/5HfBJ7VjM4pzaW7vkVk8HFAvQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR0401MB2512 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Apr 09, 2021 at 03:24:28PM +0300, Dan Carpenter wrote: > This loop will try to unmap enetc_unmap_tx_buff[-1] and crash. >=20 > Fixes: 9d2b68cc108d ("net: enetc: add support for XDP_REDIRECT") > Signed-off-by: Dan Carpenter > --- > drivers/net/ethernet/freescale/enetc/enetc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/e= thernet/freescale/enetc/enetc.c > index 57049ae97201..d86395775ed0 100644 > --- a/drivers/net/ethernet/freescale/enetc/enetc.c > +++ b/drivers/net/ethernet/freescale/enetc/enetc.c > @@ -895,7 +895,7 @@ static int enetc_xdp_frame_to_xdp_tx_swbd(struct enet= c_bdr *tx_ring, > dma =3D dma_map_single(tx_ring->dev, data, len, DMA_TO_DEVICE); > if (unlikely(dma_mapping_error(tx_ring->dev, dma))) { > /* Undo the DMA mapping for all fragments */ > - while (n-- >=3D 0) > + while (--n >=3D 0) > enetc_unmap_tx_buff(tx_ring, &xdp_tx_arr[n]); > =20 > netdev_err(tx_ring->ndev, "DMA map error\n"); > --=20 > 2.30.2 >=20 I have no idea what went wrong. I distinctly remember "testing" this by writing up a small program: #include int main(void) { int n =3D 5; while (n-- >=3D 0) printf("%d\n", n); return 0; } I find myself doing that most of the time when there is a need for an unrolling loop. I do see that this goes down to -1, I wonder how I missed it. Reviewed-by: Vladimir Oltean =