From eebfb643c0799ecb98ba77d4a0dd0e56f6a17553 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Thu, 22 Jan 2015 12:40:13 +0000 Subject: sh_eth: Fix padding of short frames on TX If an skb to be transmitted is shorter than the minimum Ethernet frame length, we currently set the DMA descriptor length to the minimum but do not add zero-padding. This could result in leaking sensitive data. We also pass different lengths to dma_map_single() and dma_unmap_single(). Use skb_padto() to pad properly, before calling dma_map_single(). Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index 6576243..4ae22fc 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -2117,6 +2117,9 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev) } spin_unlock_irqrestore(&mdp->lock, flags); + if (skb_padto(skb, ETH_ZLEN)) + return NETDEV_TX_OK; + entry = mdp->cur_tx % mdp->num_tx_ring; mdp->tx_skbuff[entry] = skb; txdesc = &mdp->tx_ring[entry]; @@ -2126,10 +2129,7 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev) skb->len + 2); txdesc->addr = dma_map_single(&ndev->dev, skb->data, skb->len, DMA_TO_DEVICE); - if (skb->len < ETH_ZLEN) - txdesc->buffer_length = ETH_ZLEN; - else - txdesc->buffer_length = skb->len; + txdesc->buffer_length = skb->len; if (entry >= mdp->num_tx_ring - 1) txdesc->status |= cpu_to_edmac(mdp, TD_TACT | TD_TDLE); -- cgit v0.10.2