From 9256db4e45e8b497b0e993cc3ed4ad08eb2389b6 Mon Sep 17 00:00:00 2001 From: Yuri Karpov Date: Thu, 24 Nov 2022 11:43:03 +0300 Subject: 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 Reviewed-by: Maciej Fijalkowski Signed-off-by: David S. Miller --- drivers/net/ethernet/ni/nixge.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/drivers/net/ethernet/ni/nixge.c b/drivers/net/ethernet/ni/nixge.c index 19d043b593cc..62320be4de5a 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); -- cgit