diff mbox series

[net,v2] net: lantiq: fix memory corruption in RX ring

Message ID 20210521144558.2071-1-olek2@wp.pl (mailing list archive)
State Accepted
Commit c7718ee96dbc2f9c5fc3b578abdf296dd44b9c20
Delegated to: Netdev Maintainers
Headers show
Series [net,v2] net: lantiq: fix memory corruption in RX ring | expand

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Commit Message

Aleksander Jan Bajkowski May 21, 2021, 2:45 p.m. UTC
In a situation where memory allocation or dma mapping fails, an
invalid address is programmed into the descriptor. This can lead
to memory corruption. If the memory allocation fails, DMA should
reuse the previous skb and mapping and drop the packet. This patch
also increments rx drop counter.

Fixes: fe1a56420cf2 ("net: lantiq: Add Lantiq / Intel VRX200 Ethernet driver ")
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
---
 drivers/net/ethernet/lantiq_xrx200.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org May 21, 2021, 9:30 p.m. UTC | #1
Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Fri, 21 May 2021 16:45:58 +0200 you wrote:
> In a situation where memory allocation or dma mapping fails, an
> invalid address is programmed into the descriptor. This can lead
> to memory corruption. If the memory allocation fails, DMA should
> reuse the previous skb and mapping and drop the packet. This patch
> also increments rx drop counter.
> 
> Fixes: fe1a56420cf2 ("net: lantiq: Add Lantiq / Intel VRX200 Ethernet driver ")
> Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
> 
> [...]

Here is the summary with links:
  - [net,v2] net: lantiq: fix memory corruption in RX ring
    https://git.kernel.org/netdev/net/c/c7718ee96dbc

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
index 41c2ad210bc9..36dc3e5f6218 100644
--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -154,6 +154,7 @@  static int xrx200_close(struct net_device *net_dev)
 
 static int xrx200_alloc_skb(struct xrx200_chan *ch)
 {
+	dma_addr_t mapping;
 	int ret = 0;
 
 	ch->skb[ch->dma.desc] = netdev_alloc_skb_ip_align(ch->priv->net_dev,
@@ -163,16 +164,17 @@  static int xrx200_alloc_skb(struct xrx200_chan *ch)
 		goto skip;
 	}
 
-	ch->dma.desc_base[ch->dma.desc].addr = dma_map_single(ch->priv->dev,
-			ch->skb[ch->dma.desc]->data, XRX200_DMA_DATA_LEN,
-			DMA_FROM_DEVICE);
-	if (unlikely(dma_mapping_error(ch->priv->dev,
-				       ch->dma.desc_base[ch->dma.desc].addr))) {
+	mapping = dma_map_single(ch->priv->dev, ch->skb[ch->dma.desc]->data,
+				 XRX200_DMA_DATA_LEN, DMA_FROM_DEVICE);
+	if (unlikely(dma_mapping_error(ch->priv->dev, mapping))) {
 		dev_kfree_skb_any(ch->skb[ch->dma.desc]);
 		ret = -ENOMEM;
 		goto skip;
 	}
 
+	ch->dma.desc_base[ch->dma.desc].addr = mapping;
+	/* Make sure the address is written before we give it to HW */
+	wmb();
 skip:
 	ch->dma.desc_base[ch->dma.desc].ctl =
 		LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
@@ -196,6 +198,8 @@  static int xrx200_hw_receive(struct xrx200_chan *ch)
 	ch->dma.desc %= LTQ_DESC_NUM;
 
 	if (ret) {
+		ch->skb[ch->dma.desc] = skb;
+		net_dev->stats.rx_dropped++;
 		netdev_err(net_dev, "failed to allocate new rx buffer\n");
 		return ret;
 	}