rtl818x: make dev_alloc_skb() null pointer check to really work

During driver initialization, some skbs are preallocated for RX.
Currenly if the allocation fails, the driver's allocation routine
exits immediatly but it will return zero (success) anyway.

In this way the driver will continue initialization with buggy
pointers around.

This patch makes the driver's allocation routine to return
an error value and to print a complaint message when skb allocation
fails.
In this way its caller will not go further, avoinding the driver to
successfully load, and preventing dereferencing buggy pointers.

An hint is thus printed about why the driver failed.

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 0102da2f145a49c2843b27d714e7ee89459c0768..a9af83ef24adc85de7d17274596566f404b4734d 100644 (file)
--- a/drivers/net/wireless/rtl818x/rtl8180/dev.c
+++ b/drivers/net/wireless/rtl818x/rtl8180/dev.c
@@ -476,9 +476,10 @@ static int rtl8180_init_rx_ring(struct ieee80211_hw *dev)
                struct sk_buff *skb = dev_alloc_skb(MAX_RX_SIZE);
                dma_addr_t *mapping;
                entry = &priv->rx_ring[i];
-               if (!skb)
-                       return 0;
-
+               if (!skb) {
+                       wiphy_err(dev->wiphy, "Cannot allocate RX skb\n");
+                       return -ENOMEM;
+               }
                priv->rx_buf[i] = skb;
                mapping = (dma_addr_t *)skb->cb;
                *mapping = pci_map_single(priv->pdev, skb_tail_pointer(skb),