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authorJia-Ju Bai <baijiaju1990@gmail.com>2020-11-19 09:52:05 +0800
committerKalle Valo <kvalo@codeaurora.org>2020-11-24 17:06:37 +0200
commitff76548338947c2c45b7aaf1d182e331398279b7 (patch)
treec253df3606ca75e4cbdc7033108eda3f90cac082
parentc7ba0ea0df370975a484c30e711e8a483c1b96a4 (diff)
rtlwifi: rtl8192de: avoid accessing the data mapped to streaming DMA
In rtl92de_tx_fill_cmddesc(), skb->data is mapped to streaming DMA on line 667: dma_addr_t mapping = dma_map_single(..., skb->data, ...); On line 669, 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 670: __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/20201119015205.12162-1-baijiaju1990@gmail.com
-rw-r--r--drivers/net/wireless/realtek/rtlwifi/rtl8192de/trx.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/trx.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/trx.c
index 8944712274b5..c02813fba934 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/trx.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/trx.c
@@ -664,12 +664,14 @@ void rtl92de_tx_fill_cmddesc(struct ieee80211_hw *hw,
struct rtl_ps_ctl *ppsc = rtl_psc(rtlpriv);
struct rtl_hal *rtlhal = rtl_hal(rtlpriv);
u8 fw_queue = QSLT_BEACON;
- 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;
__le32 *pdesc = (__le32 *)pdesc8;
+ 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");