| Message ID | 20201118015314.4979-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | [v2,1/4] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA | expand |
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");
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"); >
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. >
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");
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(-)