Subject: Re: [PATCH v2 1/4 resend] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA

From: Kalle Valo <[email-masked]>
Date: Tue, 24 Nov 2020 15:07:02 +0000 (UTC)

Jia-Ju Bai <[email-masked]> 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 <[email-masked]>

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

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