[PATCH] net: natsemi: ns83820: add checks for dma mapping error

[Alexey Khoroshilov]

The driver does not check if mapping dma memory succeed.
The patch adds the checks and failure handling.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshi...@ispras.ru>
---
 drivers/net/ethernet/natsemi/ns83820.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/natsemi/ns83820.c 
b/drivers/net/ethernet/natsemi/ns83820.c
index 729095db3e08..7d6d692ebb92 100644
--- a/drivers/net/ethernet/natsemi/ns83820.c
+++ b/drivers/net/ethernet/natsemi/ns83820.c
@@ -534,14 +534,19 @@ static inline int ns83820_add_rx_skb(struct ns83820 *dev, 
struct sk_buff *skb)
                );
 #endif
 
+       buf = pci_map_single(dev->pci_dev, skb->data,
+                            REAL_RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
+       if (pci_dma_mapping_error(dev->pci_dev, buf)) {
+               kfree_skb(skb);
+               return 1;
+       }
+
        sg = dev->rx_info.descs + (next_empty * DESC_SIZE);
        BUG_ON(NULL != dev->rx_info.skbs[next_empty]);
        dev->rx_info.skbs[next_empty] = skb;
 
        dev->rx_info.next_empty = (next_empty + 1) % NR_RX_DESC;
        cmdsts = REAL_RX_BUF_SIZE | CMDSTS_INTR;
-       buf = pci_map_single(dev->pci_dev, skb->data,
-                            REAL_RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
        build_rx_desc(dev, sg, 0, buf, cmdsts, 0);
        /* update link of previous rx */
        if (likely(next_empty != dev->rx_info.next_rx))
@@ -1136,6 +1141,10 @@ static netdev_tx_t ns83820_hard_start_xmit(struct 
sk_buff *skb,
        if (nr_frags)
                len -= skb->data_len;
        buf = pci_map_single(dev->pci_dev, skb->data, len, PCI_DMA_TODEVICE);
+       if (pci_dma_mapping_error(dev->pci_dev, buf)) {
+               dev_kfree_skb_any(skb);
+               return NETDEV_TX_OK;
+       }
 
        first_desc = dev->tx_descs + (free_idx * DESC_SIZE);
 
-- 
2.7.4