From patchwork Thu Nov 19 01:51:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jia-Ju Bai X-Patchwork-Id: 328910 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 F3684C6369E for ; Thu, 19 Nov 2020 01:52:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CA83246B0 for ; Thu, 19 Nov 2020 01:52:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ajV/Z+fh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727478AbgKSBwD (ORCPT ); Wed, 18 Nov 2020 20:52:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726413AbgKSBwC (ORCPT ); Wed, 18 Nov 2020 20:52:02 -0500 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F608C0613D4; Wed, 18 Nov 2020 17:52:01 -0800 (PST) Received: by mail-pf1-x441.google.com with SMTP id w6so2931723pfu.1; Wed, 18 Nov 2020 17:52:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=Lrkjv0IBlzMwL2dF9c7iw3uUdxBLddCoE9twLMsxPXo=; b=ajV/Z+fhiyNanIOxETfhfJLaJYHu+1oGRqUi3qlpaKI5gFOLbbEs72B5mWjPHClM0k OxRw427HObo7ge9kr1+jvq0gJQtADcoDfoadEalIpdqXTKU9dN7XCkWzPPQ74KrHjfq4 loy/w3NvIUDCctLNfJ8WNmSVyi37D+9VUZBbUMg9kEp6bKt9m4HxiwFWE3oA2aW8xe3e WITAKDZAj1qsHC6N62QZWBOZzXAhR/gtkdT2AZM5CDlVlqbD2EzBgt2NDGpFi8GqnmEy LdCCAlSVTAvJHqiHbuMYr9ajlgL0zLMRscoVdBmeRDsWTPFSr1j2cTT85J3mSboDB5wu nAxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=Lrkjv0IBlzMwL2dF9c7iw3uUdxBLddCoE9twLMsxPXo=; b=R4xpkYnsjsO0m7hY0TW7zJnjyI9itC8UDrLbbCyG/K3WG8Orm91Z4/Sowyg3fb8Izg iFdhgbZ0Aaukqv711g7FdGC4ijLfpWgwlFhogSHpMeJcWHOivwDiKKEBCS4/t9ztEhVS x5HlIE8RdE1+h8SWDrczEvONv3ryN2P80p99DqiNns/h6rQwYRE6oTEyqqHyJvVnhKvV 71Aph4u8YIQwETDOMh4wIM4Y8+BwdsbJeZm8MvegIP0P09PdJduc39L6OUlGxLDCzuxS 7OYOhR60aHN6VJBCszVyjQfjtsQUigvw92wNHZOG6t1LeKKamVCPx9U/rpwMQ5ryjhib novw== X-Gm-Message-State: AOAM531EIW0oB1LR2oPS5tSEHxClWxSq4pU/N+Ey8RpsX+eoeZy9nZdY nryvVRCqU5KN/PsJKqtM9LA= X-Google-Smtp-Source: ABdhPJxO8eA5HqG71Zp8OEePb2qToBb3iQ+7QEwSvpJmyRzGwheiB6FSeLPerEjOpyAvQ3/G4hF74g== X-Received: by 2002:a05:6a00:1684:b029:18b:665e:5211 with SMTP id k4-20020a056a001684b029018b665e5211mr6947014pfc.20.1605750720578; Wed, 18 Nov 2020 17:52:00 -0800 (PST) Received: from localhost.localdomain ([45.56.153.149]) by smtp.gmail.com with ESMTPSA id b1sm9799308pgg.74.2020.11.18.17.51.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Nov 2020 17:51:59 -0800 (PST) From: Jia-Ju Bai To: pkshih@realtek.com, kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org, Larry.Finger@lwfinger.net Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH v2 2/4 resend] rtlwifi: rtl8192ce: avoid accessing the data mapped to streaming DMA Date: Thu, 19 Nov 2020 09:51:51 +0800 Message-Id: <20201119015151.12110-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org In rtl92ce_tx_fill_cmddesc(), skb->data is mapped to streaming DMA on line 530: dma_addr_t mapping = dma_map_single(..., skb->data, ...); On line 533, skb->data is assigned to hdr after cast: struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)(skb->data); Then hdr->frame_control is accessed on line 534: __le16 fc = hdr->frame_control; This DMA access may cause data inconsistency between CPU and hardwre. To fix this bug, hdr->frame_control is accessed before the DMA mapping. Signed-off-by: Jia-Ju Bai --- v2: * Use "rtlwifi" as subject prefix and have all rtlwifi patches in the same pathset. Thank Ping and Larry for good advice. --- drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c index c0635309a92d..4165175cf5c0 100644 --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c @@ -527,12 +527,12 @@ void rtl92ce_tx_fill_cmddesc(struct ieee80211_hw *hw, u8 fw_queue = QSLT_BEACON; __le32 *pdesc = (__le32 *)pdesc8; - dma_addr_t mapping = dma_map_single(&rtlpci->pdev->dev, skb->data, - skb->len, DMA_TO_DEVICE); - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)(skb->data); __le16 fc = hdr->frame_control; + dma_addr_t mapping = dma_map_single(&rtlpci->pdev->dev, skb->data, + skb->len, DMA_TO_DEVICE); + if (dma_mapping_error(&rtlpci->pdev->dev, mapping)) { rtl_dbg(rtlpriv, COMP_SEND, DBG_TRACE, "DMA mapping error\n");