Patch "net: ethernet: nixge: fix NULL dereference" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net: ethernet: nixge: fix NULL dereference

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-ethernet-nixge-fix-null-dereference.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 9511b639ed687567d89ef86c9fda048828b3d286
Author: Yuri Karpov <YKarpov@xxxxxxxxx>
Date:   Thu Nov 24 11:43:03 2022 +0300

    net: ethernet: nixge: fix NULL dereference
    
    [ Upstream commit 9256db4e45e8b497b0e993cc3ed4ad08eb2389b6 ]
    
    In function nixge_hw_dma_bd_release() dereference of NULL pointer
    priv->rx_bd_v is possible for the case of its allocation failure in
    nixge_hw_dma_bd_init().
    
    Move for() loop with priv->rx_bd_v dereference under the check for
    its validity.
    
    Found by Linux Verification Center (linuxtesting.org) with SVACE.
    
    Fixes: 492caffa8a1a ("net: ethernet: nixge: Add support for National Instruments XGE netdev")
    Signed-off-by: Yuri Karpov <YKarpov@xxxxxxxxx>
    Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/ni/nixge.c b/drivers/net/ethernet/ni/nixge.c
index 057b7419404d..5d0cecf80b38 100644
--- a/drivers/net/ethernet/ni/nixge.c
+++ b/drivers/net/ethernet/ni/nixge.c
@@ -249,25 +249,26 @@ static void nixge_hw_dma_bd_release(struct net_device *ndev)
 	struct sk_buff *skb;
 	int i;
 
-	for (i = 0; i < RX_BD_NUM; i++) {
-		phys_addr = nixge_hw_dma_bd_get_addr(&priv->rx_bd_v[i],
-						     phys);
-
-		dma_unmap_single(ndev->dev.parent, phys_addr,
-				 NIXGE_MAX_JUMBO_FRAME_SIZE,
-				 DMA_FROM_DEVICE);
-
-		skb = (struct sk_buff *)(uintptr_t)
-			nixge_hw_dma_bd_get_addr(&priv->rx_bd_v[i],
-						 sw_id_offset);
-		dev_kfree_skb(skb);
-	}
+	if (priv->rx_bd_v) {
+		for (i = 0; i < RX_BD_NUM; i++) {
+			phys_addr = nixge_hw_dma_bd_get_addr(&priv->rx_bd_v[i],
+							     phys);
+
+			dma_unmap_single(ndev->dev.parent, phys_addr,
+					 NIXGE_MAX_JUMBO_FRAME_SIZE,
+					 DMA_FROM_DEVICE);
+
+			skb = (struct sk_buff *)(uintptr_t)
+				nixge_hw_dma_bd_get_addr(&priv->rx_bd_v[i],
+							 sw_id_offset);
+			dev_kfree_skb(skb);
+		}
 
-	if (priv->rx_bd_v)
 		dma_free_coherent(ndev->dev.parent,
 				  sizeof(*priv->rx_bd_v) * RX_BD_NUM,
 				  priv->rx_bd_v,
 				  priv->rx_bd_p);
+	}
 
 	if (priv->tx_skb)
 		devm_kfree(ndev->dev.parent, priv->tx_skb);