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 <[email protected]>
---
drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c
index c0635309a92d..4165175cf5c0 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c
@@ -527,12 +527,12 @@ void rtl92ce_tx_fill_cmddesc(struct ieee80211_hw *hw,
u8 fw_queue = QSLT_BEACON;
__le32 *pdesc = (__le32 *)pdesc8;
- dma_addr_t mapping = dma_map_single(&rtlpci->pdev->dev, skb->data,
- skb->len, DMA_TO_DEVICE);
-
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)(skb->data);
__le16 fc = hdr->frame_control;
+ dma_addr_t mapping = dma_map_single(&rtlpci->pdev->dev, skb->data,
+ skb->len, DMA_TO_DEVICE);
+
if (dma_mapping_error(&rtlpci->pdev->dev, mapping)) {
rtl_dbg(rtlpriv, COMP_SEND, DBG_TRACE,
"DMA mapping error\n");
--
2.17.1
On Mon, 2020-10-19 at 11:09 +0800, Jia-Ju Bai 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 <[email protected]>
> ---
> drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c
> b/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c
> index c0635309a92d..4165175cf5c0 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/trx.c
> @@ -527,12 +527,12 @@ void rtl92ce_tx_fill_cmddesc(struct ieee80211_hw *hw,
> u8 fw_queue = QSLT_BEACON;
> __le32 *pdesc = (__le32 *)pdesc8;
>
> - dma_addr_t mapping = dma_map_single(&rtlpci->pdev->dev, skb->data,
> - skb->len, DMA_TO_DEVICE);
> -
> struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)(skb->data);
> __le16 fc = hdr->frame_control;
>
> + dma_addr_t mapping = dma_map_single(&rtlpci->pdev->dev, skb->data,
> + skb->len, DMA_TO_DEVICE);
> +
> if (dma_mapping_error(&rtlpci->pdev->dev, mapping)) {
> rtl_dbg(rtlpriv, COMP_SEND, DBG_TRACE,
> "DMA mapping error\n");
The changes of the series patches are good to me.
But, please use 'rtlwifi: ' as subject prefix, like "rtlwifi: rtl8192ce: ...",
and send them as a patchset I think this would be better to maintainer.
Thank you
---
PK
Jia-Ju Bai <[email protected]> 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 <[email protected]>
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
--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
On 2020/11/7 19:44, Kalle Valo wrote:
> Jia-Ju Bai <[email protected]> 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 <[email protected]>
> 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