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

From: Kalle Valo
Date: Tue Nov 24 2020 - 10:07:15 EST


Jia-Ju Bai <baijiaju1990@xxxxxxxxx> 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@xxxxxxxxx>

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@xxxxxxxxx/

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