DMA buffer memory must be synchronized and copied before passing skb to napi_gro_receive(). The use of build_skb() can lead to memory corruption, replace it with netdev_alloc_skb_ip_align() and memcpy().
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=69041 Signed-off-by: Jonas Jensen <jonas.jen...@gmail.com> --- Notes: This fixes the following error on wget download (or ncftp), usually after only a few seconds: "read error: Bad address" On receiving this error, wget exits. The download is not resumed (busybox default). Applies to next-20140120 drivers/net/ethernet/moxa/moxart_ether.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/moxa/moxart_ether.c b/drivers/net/ethernet/moxa/moxart_ether.c index aa45607..17c9f0e 100644 --- a/drivers/net/ethernet/moxa/moxart_ether.c +++ b/drivers/net/ethernet/moxa/moxart_ether.c @@ -226,14 +226,21 @@ static int moxart_rx_poll(struct napi_struct *napi, int budget) if (len > RX_BUF_SIZE) len = RX_BUF_SIZE; - skb = build_skb(priv->rx_buf[rx_head], priv->rx_buf_size); + dma_sync_single_for_cpu(&ndev->dev, + priv->rx_mapping[rx_head], + priv->rx_buf_size, DMA_FROM_DEVICE); + skb = netdev_alloc_skb_ip_align(ndev, len); if (unlikely(!skb)) { - net_dbg_ratelimited("build_skb failed\n"); + net_dbg_ratelimited("netdev_alloc_skb_ip_align failed\n"); priv->stats.rx_dropped++; priv->stats.rx_errors++; } - + memcpy(skb->data, priv->rx_buf[rx_head], len); skb_put(skb, len); + dma_sync_single_for_device(&ndev->dev, + priv->rx_mapping[rx_head], + priv->rx_buf_size, DMA_FROM_DEVICE); + skb->protocol = eth_type_trans(skb, ndev); napi_gro_receive(&priv->napi, skb); rx++; -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
