GRETH: fixed skb buffer memory leak on frame errors

A new SKB buffer should not be allocated when the old SKB is reused.

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/greth.c b/drivers/net/greth.c
index 869e38d6f41b3abd92ea2a941c5e0dfcce3a4213..9386bce9dea501fd957d971a47158993401b2950 100644 (file)
--- a/drivers/net/greth.c
+++ b/drivers/net/greth.c
@@ -870,10 +870,9 @@ static int greth_rx_gbit(struct net_device *dev, int limit)
                        }
                }
 
-               /* Allocate new skb to replace current */
-               newskb = netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN);
-
-               if (!bad && newskb) {
+               /* Allocate new skb to replace current, not needed if the
+                * current skb can be reused */
+               if (!bad && (newskb=netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN))) {
                        skb_reserve(newskb, NET_IP_ALIGN);
 
                        dma_addr = dma_map_single(greth->dev,
@@ -910,11 +909,22 @@ static int greth_rx_gbit(struct net_device *dev, int limit)
                                if (net_ratelimit())
                                        dev_warn(greth->dev, "Could not create DMA mapping, dropping packet\n");
                                dev_kfree_skb(newskb);
+                               /* reusing current skb, so it is a drop */
                                dev->stats.rx_dropped++;
                        }
+               } else if (bad) {
+                       /* Bad Frame transfer, the skb is reused */
+                       dev->stats.rx_dropped++;
                } else {
+                       /* Failed Allocating a new skb. This is rather stupid
+                        * but the current "filled" skb is reused, as if
+                        * transfer failure. One could argue that RX descriptor
+                        * table handling should be divided into cleaning and
+                        * filling as the TX part of the driver
+                        */
                        if (net_ratelimit())
                                dev_warn(greth->dev, "Could not allocate SKB, dropping packet\n");
+                       /* reusing current skb, so it is a drop */
                        dev->stats.rx_dropped++;
                }