Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: kvalo=codeaurora.org@mg.codeaurora.org
DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 42B4BC433ED
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Subject: Re: [PATCH v2 1/4 resend] rtlwifi: rtl8188ee: avoid accessing the
 data
 mapped to streaming DMA
From:   Kalle Valo <kvalo@codeaurora.org>
In-Reply-To: <20201119015127.12033-1-baijiaju1990@gmail.com>
References: <20201119015127.12033-1-baijiaju1990@gmail.com>
To:     Jia-Ju Bai <baijiaju1990@gmail.com>
Cc:     pkshih@realtek.com, davem@davemloft.net, kuba@kernel.org,
        Larry.Finger@lwfinger.net, linux-wireless@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jia-Ju Bai <baijiaju1990@gmail.com>
User-Agent: pwcli/0.1.0-git (https://github.com/kvalo/pwcli/) Python/3.5.2
Message-Id: <20201124150702.C911EC43461@smtp.codeaurora.org>
Date:   Tue, 24 Nov 2020 15:07:02 +0000 (UTC)
Precedence: bulk

Jia-Ju Bai <baijiaju1990@gmail.com> wrote:

> In rtl88ee_tx_fill_cmddesc(), skb->data is mapped to streaming DMA on
> line 677:
>   dma_addr_t mapping = dma_map_single(..., skb->data, ...);
> 
> On line 680, 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 681:
>   __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 <baijiaju1990@gmail.com>

4 patches applied to wireless-drivers-next.git, thanks.

6df3c293d284 rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA
c7ba0ea0df37 rtlwifi: rtl8192ce: avoid accessing the data mapped to streaming DMA
ff7654833894 rtlwifi: rtl8192de: avoid accessing the data mapped to streaming DMA
8b2c13b2e5da rtlwifi: rtl8723ae: avoid accessing the data mapped to streaming DMA

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20201119015127.12033-1-baijiaju1990@gmail.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches