| Message ID | 20201119015127.12033-1-baijiaju1990@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/4,resend] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA | expand |
Jia-Ju Bai <baijiaju1990@gmail.com> 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> 4 patches applied to wireless-drivers-next.git, thanks. 6df3c293d284 rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA c7ba0ea0df37 rtlwifi: rtl8192ce: avoid accessing the data mapped to streaming DMA ff7654833894 rtlwifi: rtl8192de: avoid accessing the data mapped to streaming DMA 8b2c13b2e5da rtlwifi: rtl8723ae: avoid accessing the data mapped to streaming DMA -- https://patchwork.kernel.org/project/linux-wireless/patch/20201119015127.12033-1-baijiaju1990@gmail.com/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
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> --- v2: * Use "rtlwifi" as subject prefix and have all rtlwifi patches in the same pathset. Thank Ping and Larry for good advice. --- drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)