diff options
| author | Jia-Ju Bai <baijiaju@tsinghua.edu.cn> | 2020-08-02 21:29:49 +0800 |
|---|---|---|
| committer | Kalle Valo <kvalo@codeaurora.org> | 2020-09-01 12:33:48 +0300 |
| commit | 478762855b5ae9f68fa6ead1edf7abada70fcd5f (patch) | |
| tree | cb20ae2a895e4f9c728450388ebf688977a26d6f /drivers/net/wireless/intersil | |
| parent | e9cf68ff4eff35c1724f0f43309fa1d919292592 (diff) | |
| download | linux-next-478762855b5ae9f68fa6ead1edf7abada70fcd5f.tar.gz | |
p54: avoid accessing the data mapped to streaming DMA
In p54p_tx(), skb->data is mapped to streaming DMA on line 337:
mapping = pci_map_single(..., skb->data, ...);
Then skb->data is accessed on line 349:
desc->device_addr = ((struct p54_hdr *)skb->data)->req_id;
This access may cause data inconsistency between CPU cache and hardware.
To fix this problem, ((struct p54_hdr *)skb->data)->req_id is stored in
a local variable before DMA mapping, and then the driver accesses this
local variable instead of skb->data.
Cc: <stable@vger.kernel.org>
Signed-off-by: Jia-Ju Bai <baijiaju@tsinghua.edu.cn>
Acked-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200802132949.26788-1-baijiaju@tsinghua.edu.cn
Diffstat (limited to 'drivers/net/wireless/intersil')
| -rw-r--r-- | drivers/net/wireless/intersil/p54/p54pci.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/net/wireless/intersil/p54/p54pci.c b/drivers/net/wireless/intersil/p54/p54pci.c index 94064d7cff52..e97ee547b9f3 100644 --- a/drivers/net/wireless/intersil/p54/p54pci.c +++ b/drivers/net/wireless/intersil/p54/p54pci.c @@ -333,10 +333,12 @@ static void p54p_tx(struct ieee80211_hw *dev, struct sk_buff *skb) struct p54p_desc *desc; dma_addr_t mapping; u32 idx, i; + __le32 device_addr; spin_lock_irqsave(&priv->lock, flags); idx = le32_to_cpu(ring_control->host_idx[1]); i = idx % ARRAY_SIZE(ring_control->tx_data); + device_addr = ((struct p54_hdr *)skb->data)->req_id; mapping = dma_map_single(&priv->pdev->dev, skb->data, skb->len, DMA_TO_DEVICE); @@ -350,7 +352,7 @@ static void p54p_tx(struct ieee80211_hw *dev, struct sk_buff *skb) desc = &ring_control->tx_data[i]; desc->host_addr = cpu_to_le32(mapping); - desc->device_addr = ((struct p54_hdr *)skb->data)->req_id; + desc->device_addr = device_addr; desc->len = cpu_to_le16(skb->len); desc->flags = 0; |