| Message ID | 20201119015218.12220-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v2,1/4,resend] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/trx.c b/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/trx.c index e3ee91b7ea8d..340b3d68a54e 100644 --- a/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/trx.c +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/trx.c @@ -528,12 +528,12 @@ void rtl8723e_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 rtl8723e_tx_fill_cmddesc(), skb->data is mapped to streaming DMA on line 531: dma_addr_t mapping = dma_map_single(..., skb->data, ...); On line 534, 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 535: __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/rtl8723ae/trx.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)