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authorJia-Ju Bai <baijiaju1990@gmail.com>2020-11-19 09:51:27 +0800
committerKalle Valo <kvalo@codeaurora.org>2020-11-24 17:06:34 +0200
commit6df3c293d284655c72c1a72356ce4d32217a9c54 (patch)
treea1385980901f9a21769761486ef4afe369d3ae80
parent00331758137245fd3478404ee81de40dfcb3b7de (diff)
rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA
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> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Link: https://lore.kernel.org/r/20201119015127.12033-1-baijiaju1990@gmail.com
-rw-r--r--drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c6
1 files 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");