Re: [PATCH] rtl8192ce: avoid accessing the data mapped to streaming DMA

Jia-Ju Bai
2020-11-18T01:56:21Z

On 2020/11/7 19:44, Kalle Valo wrote:
> Jia-Ju Bai <baijiaju1990@gmail.com> wrote:
>
>> In rtl92ce_tx_fill_cmddesc(), skb->data is mapped to streaming DMA on
>> line 530:
>> dma_addr_t mapping = dma_map_single(..., skb->data, ...);
>>
>> On line 533, 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 534:
>> __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>
> Like Ping said, use "rtlwifi:" prefix and have all rtlwifi patches in
> the same patchset.
>
> 4 patches set to Changes Requested.
>
> 11843533 rtl8192ce: avoid accessing the data mapped to streaming DMA
> 11843541 rtl8192de: avoid accessing the data mapped to streaming DMA
> 11843553 rtl8723ae: avoid accessing the data mapped to streaming DMA
> 11843557 rtl8188ee: avoid accessing the data mapped to streaming DMA
>

Okay, I have sent v2 patches just now.
Please have a look, thank :)

Best wishes,
Jia-Ju Bai