From nobody Fri Sep 20 11:22:04 2024 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 5BEA5EE49A4 for ; Sun, 10 Sep 2023 21:41:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231489AbjIJVlI (ORCPT ); Sun, 10 Sep 2023 17:41:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229604AbjIJVlI (ORCPT ); Sun, 10 Sep 2023 17:41:08 -0400 Received: from pidgin.makrotopia.org (pidgin.makrotopia.org [185.142.180.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12037188; Sun, 10 Sep 2023 14:41:02 -0700 (PDT) Received: from local by pidgin.makrotopia.org with esmtpsa (TLS1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.96) (envelope-from ) id 1qfSAe-0005D1-19; Sun, 10 Sep 2023 21:40:44 +0000 Date: Sun, 10 Sep 2023 22:40:30 +0100 From: Daniel Golle To: Dan Carpenter , Felix Fietkau , John Crispin , Sean Wang , Mark Lee , Lorenzo Bianconi , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Matthias Brugger , AngeloGioacchino Del Regno , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH net v2] net: ethernet: mtk_eth_soc: fix uninitialized variable Message-ID: <30044cf16ff83f73e5ef852c25682e9fde63af51.1694376191.git.daniel@makrotopia.org> References: <9918f1ae-5604-4bdc-a654-e0566ca77ad6@moroto.mountain> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <9918f1ae-5604-4bdc-a654-e0566ca77ad6@moroto.mountain> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Variable dma_addr in function mtk_poll_rx can be uninitialized on some of the error paths. In practise this doesn't matter, even random data present in uninitialized stack memory can safely be used in the way it happens in the error path. However, in order to make Smatch happy make sure the variable is always initialized. Signed-off-by: Daniel Golle --- v2: initialize with DMA_MAPPING_ERROR instead of NULL drivers/net/ethernet/mediatek/mtk_eth_soc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethe= rnet/mediatek/mtk_eth_soc.c index 31090490d47ce..6145ddcff206c 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -2119,11 +2119,11 @@ static int mtk_poll_rx(struct napi_struct *napi, in= t budget, u8 *data, *new_data; struct mtk_rx_dma_v2 *rxd, trxd; int done =3D 0, bytes =3D 0; + dma_addr_t dma_addr =3D DMA_MAPPING_ERROR; =20 while (done < budget) { unsigned int pktlen, *rxdcsum; struct net_device *netdev; - dma_addr_t dma_addr; u32 hash, reason; int mac =3D 0; =20 @@ -2300,7 +2300,8 @@ static int mtk_poll_rx(struct napi_struct *napi, int = budget, else rxd->rxd2 =3D RX_DMA_PREP_PLEN0(ring->buf_size); =20 - if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA)) + if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA) && + likely(dma_addr !=3D DMA_MAPPING_ERROR)) rxd->rxd2 |=3D RX_DMA_PREP_ADDR64(dma_addr); =20 ring->calc_idx =3D idx; --=20 2.42.0