From patchwork Wed Nov 18 01:57:08 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: 327800 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 1B0C1C63777 for ; Wed, 18 Nov 2020 01:58:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA9B324248 for ; Wed, 18 Nov 2020 01:58:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="s5xp+g5k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727008AbgKRB5t (ORCPT ); Tue, 17 Nov 2020 20:57:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725730AbgKRB5s (ORCPT ); Tue, 17 Nov 2020 20:57:48 -0500 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99215C061A48; Tue, 17 Nov 2020 17:57:48 -0800 (PST) Received: by mail-pl1-x644.google.com with SMTP id d3so138498plo.4; Tue, 17 Nov 2020 17:57:48 -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=4a7zDL5lInqafK1HE5+sC1LmnDT92uD20FAhjTWB/2c=; b=s5xp+g5klPD2WapB/Q7IK1Z0TXAqCLWSgcMGccoj/cwiZX3HzKsIMb3rnXdjbL/8+r bvJCXZ0aH/lQj6Fgj3HCqo67qe3b/ZUEMWVkh9sGwq6S06hVwIY3gS8jlrXfJWKyCcop //lIEZNIXniuq4adWq2IPzDaLGQVnvb11jNu6D0Fr1AJRyWUnNn3Y/d92pycNfkP/XPl xLJltjv78d2xuE5b7q9x5Fk8a4ZP6ZywChYNAKdWw7OgLWluj6SUUWmCituDbv5DZZcA 6gJ6ZjTytgQgWLAa0FglUj/nr6yrTkiwEoyY/UtCJF053gBAqFuk4auJUQnCX9Udmb0a Kq8w== 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=4a7zDL5lInqafK1HE5+sC1LmnDT92uD20FAhjTWB/2c=; b=fJyJfwE6cB7A2l/orPBM5sm+aS3TW3A00lGzy2QaINT9PBGLKcZCbeM9cvxy2UiYJH 6091mox8grK8zoNZp6CUHNMJmD+ZYl7Oekq36YGot4TtKvZg47iV8rguM6qKtuOtgKIy jzSu+9JOu1VsaBJXQDg4BXD3eTHNf2fMmXtd2xou5n0peHomuzscXgJepakuEwUKl7c8 AplsBeKWoaGPwolL2Ga7J1n1PsWyZ0AnKOKTFLoRWezE+frIc5xwAtcAiu22OB7XG8P0 gATZsaMMpF90Tg1Hgj1ipsJyRnuX7LPcnh/YTCbOJC65LNgE+8NkdodFcuSMT+8QvYHB X4Qw== X-Gm-Message-State: AOAM5331ySRCv5xqJ/CGyWadwzXWH535IeTcu3xo3F+qSOjAWElcRrBU PLkshSUjtkDXtCsz5RRVwBw= X-Google-Smtp-Source: ABdhPJw6aJl7AaGR6mNa5ccupT7DbLlBABl/RTfldgoA3kMAQHzcLZmNZqpt992LoKTSIEWbRGo/lA== X-Received: by 2002:a17:90a:e016:: with SMTP id u22mr1935038pjy.54.1605664668234; Tue, 17 Nov 2020 17:57:48 -0800 (PST) Received: from oslab.tsinghua.edu.cn ([166.111.139.137]) by smtp.gmail.com with ESMTPSA id e201sm22988444pfh.73.2020.11.17.17.57.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Nov 2020 17:57:47 -0800 (PST) From: Jia-Ju Bai To: pkshih@realtek.com, kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH v2 4/4] rtlwifi: rtl8723ae: avoid accessing the data mapped to streaming DMA Date: Wed, 18 Nov 2020 09:57:08 +0800 Message-Id: <20201118015708.5445-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org In rtl8723e_tx_fill_cmddesc(), skb->data is mapped to streaming DMA on line 531: dma_addr_t mapping = dma_map_single(..., skb->data, ...); On line 534, 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 535: __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 --- drivers/net/wireless/realtek/rtlwifi/rtl8723ae/trx.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/trx.c b/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/trx.c index e3ee91b7ea8d..340b3d68a54e 100644 --- a/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/trx.c +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/trx.c @@ -528,12 +528,12 @@ void rtl8723e_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");