* [PATCH v2 1/4] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA
@ 2020-11-18 1:53 Jia-Ju Bai
2020-11-18 2:33 ` Pkshih
2020-11-18 17:20 ` Larry Finger
0 siblings, 2 replies; 4+ messages in thread
From: Jia-Ju Bai @ 2020-11-18 1:53 UTC (permalink / raw)
To: pkshih, kvalo, davem, kuba
Cc: linux-wireless, netdev, linux-kernel, Jia-Ju Bai
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@gmail.com>
---
drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c b/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
index b9775eec4c54..c948dafa0c80 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
@@ -674,12 +674,12 @@ void rtl88ee_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
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v2 1/4] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA
2020-11-18 1:53 [PATCH v2 1/4] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA Jia-Ju Bai
@ 2020-11-18 2:33 ` Pkshih
2020-11-18 17:20 ` Larry Finger
1 sibling, 0 replies; 4+ messages in thread
From: Pkshih @ 2020-11-18 2:33 UTC (permalink / raw)
To: baijiaju1990, kvalo, davem, kuba; +Cc: linux-wireless, netdev, linux-kernel
On Wed, 2020-11-18 at 09:53 +0800, Jia-Ju Bai 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@gmail.com>
This patchset looks good to me.
Thank you.
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
> ---
> drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
> b/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
> index b9775eec4c54..c948dafa0c80 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
> @@ -674,12 +674,12 @@ void rtl88ee_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");
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2 1/4] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA
2020-11-18 1:53 [PATCH v2 1/4] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA Jia-Ju Bai
2020-11-18 2:33 ` Pkshih
@ 2020-11-18 17:20 ` Larry Finger
2020-11-19 1:54 ` Jia-Ju Bai
1 sibling, 1 reply; 4+ messages in thread
From: Larry Finger @ 2020-11-18 17:20 UTC (permalink / raw)
To: Jia-Ju Bai, pkshih, kvalo, davem, kuba
Cc: linux-wireless, netdev, linux-kernel
On 11/17/20 7:53 PM, Jia-Ju Bai 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@gmail.com>
> ---
> drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
What changed between v1 and v2?
As outlined in Documentation/process/submitting-patches.rst, you should add a
'---' marker and descrive what was changed. I usually summarize the changes, but
it is also possible to provide a diffstat of the changes as the above file shows.
Larry
>
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c b/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
> index b9775eec4c54..c948dafa0c80 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c
> @@ -674,12 +674,12 @@ void rtl88ee_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");
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2 1/4] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA
2020-11-18 17:20 ` Larry Finger
@ 2020-11-19 1:54 ` Jia-Ju Bai
0 siblings, 0 replies; 4+ messages in thread
From: Jia-Ju Bai @ 2020-11-19 1:54 UTC (permalink / raw)
To: Larry Finger, pkshih, kvalo, davem, kuba
Cc: linux-wireless, netdev, linux-kernel
Thanks for the advice.
I have added the description of the changes and resent the patches.
Best wishes,
Jia-Ju Bai
On 2020/11/19 1:20, Larry Finger wrote:
> On 11/17/20 7:53 PM, Jia-Ju Bai 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@gmail.com>
>> ---
>> drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> What changed between v1 and v2?
>
> As outlined in Documentation/process/submitting-patches.rst, you
> should add a '---' marker and descrive what was changed. I usually
> summarize the changes, but it is also possible to provide a diffstat
> of the changes as the above file shows.
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-11-19 1:54 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2020-11-18 1:53 [PATCH v2 1/4] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA Jia-Ju Bai
2020-11-18 2:33 ` Pkshih
2020-11-18 17:20 ` Larry Finger
2020-11-19 1:54 ` Jia-Ju Bai
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