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

On 2020/11/7 19:44, Kalle Valo wrote:

Jia-Ju Bai [off-list ref] wrote:

quoted

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 <redacted>

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