From patchwork Mon Oct 19 02:54:20 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: 11843527 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A3ED81580 for ; Mon, 19 Oct 2020 02:54:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81268222C2 for ; Mon, 19 Oct 2020 02:54:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LWRKDyua" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731126AbgJSCy3 (ORCPT ); Sun, 18 Oct 2020 22:54:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728538AbgJSCy3 (ORCPT ); Sun, 18 Oct 2020 22:54:29 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 382EEC061755; Sun, 18 Oct 2020 19:54:29 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id gm14so4526164pjb.2; Sun, 18 Oct 2020 19:54:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=rMa38J/rDkdAxwNf9rq6wQwYbSWtRvfUhMh1mG4UHRM=; b=LWRKDyuansl7M2rmAC+ZFUiy7fcD1e9ApOzcSn29Uqoh3nepomEzLtI3cGa4Wn1oOa zPZFnpMhXI9C0R2FKzy/3Va3/If/Gojo4S+2RreUvJyrTnpRR5IhGPVZ6ENdnF/2cIb2 KNp35Mjr4Wvml5AYvhwJyvS3NEAQlf7I6hcmTxi6AEOosbY58ZVAnFCp0U3WmCOV8d3+ b+BLr4dtgb/wdSHYTES6mwXdmka+20v/iefPVkQ0RI31GW6SftppPfY63Mje95fyREMX Qbo7/lvR196xn573UOSWRijQ6p/JoT49m64RgDNv2fcyo7Qvv7Man5YdGnEcM+9L/ZsU LxZw== 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=rMa38J/rDkdAxwNf9rq6wQwYbSWtRvfUhMh1mG4UHRM=; b=FJHvR7Lr3UP0dkm0bA7yPxGHflASkSUN53C5tE09ZAOGf1ZF/+nyGh4FaNYjkdsL+I po442ItVQILE9KBKS31DlM817Lpe+kmikuVCdv3wbJqmGH8MliOm3Zp6UI1l24wIAuu5 26v7NX1ezD5Po+k3XW/fmEhH/B+9hG3de/XEPZz0jclTNzwSyIydBe6/rWdR0bvXmt7V bA1HimDhGht2eQB63kWIXxFZZIFfkFhdyj9YOPdUnZ+tYkEEQUdKLFX0kY8danE1SXiR xpcSx9ZIvO9JFsbbL/mnlxxIuRu8A5aRUMk52ZCqnPWEVqru8UArXs3vAMBvOyzfP3f3 Ldow== X-Gm-Message-State: AOAM530ZuaaO67zWfKOYNklPVrH1Waz0dXZ6KWFRilhfkHomv1kVdF8O //KC2PQNg8QKuKUXaOWLH9E= X-Google-Smtp-Source: ABdhPJwg4+/vETt9rhMUCFGb+vyTJmyspNuNk3VpyvR5I8/AZ5+PViHF+kkcQYFvG3KKp2x8Ffntfw== X-Received: by 2002:a17:902:8698:b029:d3:b362:7342 with SMTP id g24-20020a1709028698b02900d3b3627342mr15070350plo.50.1603076068663; Sun, 18 Oct 2020 19:54:28 -0700 (PDT) Received: from oslab.tsinghua.edu.cn ([166.111.139.137]) by smtp.gmail.com with ESMTPSA id c17sm10275529pfj.220.2020.10.18.19.54.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 18 Oct 2020 19:54:27 -0700 (PDT) From: Jia-Ju Bai To: kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org, vaibhavgupta40@gmail.com, christophe.jaillet@wanadoo.fr Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] rtl8180: avoid accessing the data mapped to streaming DMA Date: Mon, 19 Oct 2020 10:54:20 +0800 Message-Id: <20201019025420.3789-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org In rtl8180_tx(), skb->data is mapped to streaming DMA on line 476: mapping = dma_map_single(..., skb->data, ...); On line 459, skb->data is assigned to hdr after cast: struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; Then hdr->seq_ctrl is accessed on lines 540 and 541: hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG); hdr->seq_ctrl |= cpu_to_le16(priv->seqno); These DMA accesses may cause data inconsistency between CPU and hardwre. To fix this problem, hdr->seq_ctrl is accessed before the DMA mapping. Signed-off-by: Jia-Ju Bai --- drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c index 2477e18c7cae..cc73014aa5f3 100644 --- a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c +++ b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c @@ -473,6 +473,13 @@ static void rtl8180_tx(struct ieee80211_hw *dev, prio = skb_get_queue_mapping(skb); ring = &priv->tx_ring[prio]; + if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) { + if (info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT) + priv->seqno += 0x10; + hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG); + hdr->seq_ctrl |= cpu_to_le16(priv->seqno); + } + mapping = dma_map_single(&priv->pdev->dev, skb->data, skb->len, DMA_TO_DEVICE); @@ -534,13 +541,6 @@ static void rtl8180_tx(struct ieee80211_hw *dev, spin_lock_irqsave(&priv->lock, flags); - if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) { - if (info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT) - priv->seqno += 0x10; - hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG); - hdr->seq_ctrl |= cpu_to_le16(priv->seqno); - } - idx = (ring->idx + skb_queue_len(&ring->queue)) % ring->entries; entry = &ring->desc[idx];