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From:   Baochen Qiang <bqiang@codeaurora.org>
To:     ath11k@lists.infradead.org
Cc:     linux-wireless@vger.kernel.org
Subject: [PATCH v2] ath11k: Change DMA_FROM_DEVICE to DMA_TO_DEVICE when map reinjected packets
Date:   Thu, 16 Sep 2021 14:46:17 +0800
Message-Id: <20210916064617.20006-1-bqiang@codeaurora.org>
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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>
---
 drivers/net/wireless/ath/ath11k/dp_rx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index 90da56316e7e..a55dff784724 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -3434,7 +3434,7 @@ 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;
 
@@ -3499,7 +3499,7 @@ static int ath11k_dp_rx_h_defrag_reo_reinject(struct ath11k *ar, struct dp_rx_ti
 	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;
 }
 
-- 
2.25.1