rtl818x: check for pci_map_single() success when initializing RX ring

During initialization a number of RX skbs are allocated and mapped
for DMA.
Currently if pci_map_single() fails, it will result in passing to the
HW a wrong DMA address (to write to!).

This patch adds check for this condition and eventually causes the
driver not to initialize, avoiding at least dangerous DMAs.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/rtl818x/rtl8180/dev.c b/drivers/net/wireless/rtl818x/rtl8180/dev.c
index bf59ff9889520c0fd3b4ba40bef36b1e54d18095..0102da2f145a49c2843b27d714e7ee89459c0768 100644 (file)
--- a/drivers/net/wireless/rtl818x/rtl8180/dev.c
+++ b/drivers/net/wireless/rtl818x/rtl8180/dev.c
@@ -483,6 +483,13 @@ static int rtl8180_init_rx_ring(struct ieee80211_hw *dev)
                mapping = (dma_addr_t *)skb->cb;
                *mapping = pci_map_single(priv->pdev, skb_tail_pointer(skb),
                                          MAX_RX_SIZE, PCI_DMA_FROMDEVICE);
+
+               if (pci_dma_mapping_error(priv->pdev, *mapping)) {
+                       kfree_skb(skb);
+                       wiphy_err(dev->wiphy, "Cannot map DMA for RX skb\n");
+                       return -ENOMEM;
+               }
+
                entry->rx_buf = cpu_to_le32(*mapping);
                entry->flags = cpu_to_le32(RTL818X_RX_DESC_FLAG_OWN |
                                           MAX_RX_SIZE);