From patchwork Sun Sep 10 21:40:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Golle X-Patchwork-Id: 13378552 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1E5FE8BE5 for ; Sun, 10 Sep 2023 21:41:04 +0000 (UTC) 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> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <9918f1ae-5604-4bdc-a654-e0566ca77ad6@moroto.mountain> X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org 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/ethernet/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, int budget, u8 *data, *new_data; struct mtk_rx_dma_v2 *rxd, trxd; int done = 0, bytes = 0; + dma_addr_t dma_addr = DMA_MAPPING_ERROR; while (done < budget) { unsigned int pktlen, *rxdcsum; struct net_device *netdev; - dma_addr_t dma_addr; u32 hash, reason; int mac = 0; @@ -2300,7 +2300,8 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget, else rxd->rxd2 = RX_DMA_PREP_PLEN0(ring->buf_size); - if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA)) + if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA) && + likely(dma_addr != DMA_MAPPING_ERROR)) rxd->rxd2 |= RX_DMA_PREP_ADDR64(dma_addr); ring->calc_idx = idx;