From: Yuri Karpov <YKarpov@ispras.ru>
Date: Thu, 24 Nov 2022 08:43:03 +0000 (+0300)
Subject: net: ethernet: nixge: fix NULL dereference
X-Git-Tag: v6.1~51^2~19
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9256db4e45e8b497b0e993cc3ed4ad08eb2389b6;p=platform%2Fkernel%2Flinux-starfive.git

net: ethernet: nixge: fix NULL dereference

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@ispras.ru>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ethernet/ni/nixge.c b/drivers/net/ethernet/ni/nixge.c
index 19d043b..62320be 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);