ath11k: Change DMA_FROM_DEVICE to DMA_TO_DEVICE when map reinjected packets

For fragmented packets, ath11k reassembles each fragment as a normal
packet and then reinjects it into HW ring. In this case, the DMA
direction should be DMA_TO_DEVICE, not DMA_FROM_DEVICE, otherwise
invalid payload will be reinjected to HW and then delivered to host.
What is more, since arbitrary memory could be allocated to the frame, we
don't know what kind of data is contained in the buffer reinjected.
Thus, as a bad result, private info may be leaked.

Note that this issue is only found on Intel platform.

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1
Signed-off-by: Baochen Qiang <bqiang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210916064617.20006-1-bqiang@codeaurora.org

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index b145ea5..75f6d55 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -3402,7 +3402,7 @@ static int ath11k_dp_rx_h_defrag_reo_reinject(struct ath11k *ar, struct dp_rx_ti
 
        paddr = dma_map_single(ab->dev, defrag_skb->data,
                               defrag_skb->len + skb_tailroom(defrag_skb),
-                              DMA_FROM_DEVICE);
+                              DMA_TO_DEVICE);
        if (dma_mapping_error(ab->dev, paddr))
                return -ENOMEM;
 
@@ -3467,7 +3467,7 @@ err_free_idr:
        spin_unlock_bh(&rx_refill_ring->idr_lock);
 err_unmap_dma:
        dma_unmap_single(ab->dev, paddr, defrag_skb->len + skb_tailroom(defrag_skb),
-                        DMA_FROM_DEVICE);
+                        DMA_TO_DEVICE);
        return ret;
 }