The driver did not handle failure of `netdev_alloc_skb_ip_align()`. If the allocation failed, dereferencing `skb->protocol` could lead to a NULL pointer dereference. This patch adds proper error handling by falling back to the `else` clause when the allocation fails. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Tested-on: D-Link DGE-550T Rev-A3 Signed-off-by: Yeounsu Moon --- drivers/net/ethernet/dlink/dl2k.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/dlink/dl2k.c b/drivers/net/ethernet/dlink/dl2k.c index 6bbf6e5584e5..a82e1fd01b92 100644 --- a/drivers/net/ethernet/dlink/dl2k.c +++ b/drivers/net/ethernet/dlink/dl2k.c @@ -965,26 +965,31 @@ receive_packet (struct net_device *dev) struct sk_buff *skb; /* Small skbuffs for short packets */ - if (pkt_len > copy_thresh) { - dma_unmap_single(&np->pdev->dev, - desc_to_dma(desc), - np->rx_buf_sz, - DMA_FROM_DEVICE); - skb_put (skb = np->rx_skbuff[entry], pkt_len); - np->rx_skbuff[entry] = NULL; - } else if ((skb = netdev_alloc_skb_ip_align(dev, pkt_len))) { + if (pkt_len <= copy_thresh) { + skb = netdev_alloc_skb_ip_align(dev, pkt_len); + if (!skb) + goto reuse_skbuff; + dma_sync_single_for_cpu(&np->pdev->dev, desc_to_dma(desc), np->rx_buf_sz, DMA_FROM_DEVICE); - skb_copy_to_linear_data (skb, + skb_copy_to_linear_data(skb, np->rx_skbuff[entry]->data, pkt_len); - skb_put (skb, pkt_len); + skb_put(skb, pkt_len); dma_sync_single_for_device(&np->pdev->dev, desc_to_dma(desc), np->rx_buf_sz, DMA_FROM_DEVICE); + } else { +reuse_skbuff: + dma_unmap_single(&np->pdev->dev, + desc_to_dma(desc), + np->rx_buf_sz, + DMA_FROM_DEVICE); + skb_put(skb = np->rx_skbuff[entry], pkt_len); + np->rx_skbuff[entry] = NULL; } skb->protocol = eth_type_trans (skb, dev); #if 0 -- 2.51.0