yellowfin: Fix buffer underrun after dev_alloc_skb() failure

yellowfin_init_ring() needs to clean up if dev_alloc_skb() fails and
should pass an error status up to the caller. This also prevents an
buffer underrun if failure occurred in the first iteration.
yellowfin_open() which calls yellowfin_init_ring() should free its
requested irq upon failure.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 10 deletions

diff --git a/drivers/net/yellowfin.c b/drivers/net/yellowfin.c
index a07580138e81..c2fd6187773f 100644
--- a/drivers/net/yellowfin.c
+++ b/drivers/net/yellowfin.c
@@ -346,7 +346,7 @@ static int netdev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
 static int yellowfin_open(struct net_device *dev);
 static void yellowfin_timer(unsigned long data);
 static void yellowfin_tx_timeout(struct net_device *dev);
-static void yellowfin_init_ring(struct net_device *dev);
+static int yellowfin_init_ring(struct net_device *dev);
 static int yellowfin_start_xmit(struct sk_buff *skb, struct net_device *dev);
 static irqreturn_t yellowfin_interrupt(int irq, void *dev_instance);
 static int yellowfin_rx(struct net_device *dev);
@@ -573,19 +573,24 @@ static int yellowfin_open(struct net_device *dev)
 {
         struct yellowfin_private *yp = netdev_priv(dev);
         void __iomem *ioaddr = yp->base;
-        int i;
+        int i, ret;
 
         /* Reset the chip. */
         iowrite32(0x80000000, ioaddr + DMACtrl);
 
-        i = request_irq(dev->irq, &yellowfin_interrupt, IRQF_SHARED, dev->name, dev);
-        if (i) return i;
+        ret = request_irq(dev->irq, &yellowfin_interrupt, IRQF_SHARED, dev->name, dev);
+        if (ret)
+                return ret;
 
         if (yellowfin_debug > 1)
                 printk(KERN_DEBUG "%s: yellowfin_open() irq %d.\n",
                            dev->name, dev->irq);
 
-        yellowfin_init_ring(dev);
+        ret = yellowfin_init_ring(dev);
+        if (ret) {
+                free_irq(dev->irq, dev);
+                return ret;
+        }
 
         iowrite32(yp->rx_ring_dma, ioaddr + RxPtr);
         iowrite32(yp->tx_ring_dma, ioaddr + TxPtr);
@@ -725,10 +730,10 @@ static void yellowfin_tx_timeout(struct net_device *dev)
 }
 
 /* Initialize the Rx and Tx rings, along with various 'dev' bits. */
-static void yellowfin_init_ring(struct net_device *dev)
+static int yellowfin_init_ring(struct net_device *dev)
 {
         struct yellowfin_private *yp = netdev_priv(dev);
-        int i;
+        int i, j;
 
         yp->tx_full = 0;
         yp->cur_rx = yp->cur_tx = 0;
@@ -753,6 +758,11 @@ static void yellowfin_init_ring(struct net_device *dev)
                 yp->rx_ring[i].addr = cpu_to_le32(pci_map_single(yp->pci_dev,
                         skb->data, yp->rx_buf_sz, PCI_DMA_FROMDEVICE));
         }
+        if (i != RX_RING_SIZE) {
+                for (j = 0; j < i; j++)
+                        dev_kfree_skb(yp->rx_skbuff[j]);
+                return -ENOMEM;
+        }
         yp->rx_ring[i-1].dbdma_cmd = cpu_to_le32(CMD_STOP);
         yp->dirty_rx = (unsigned int)(i - RX_RING_SIZE);
 
@@ -769,8 +779,6 @@ static void yellowfin_init_ring(struct net_device *dev)
         yp->tx_ring[--i].dbdma_cmd = cpu_to_le32(CMD_STOP | BRANCH_ALWAYS);
 #else
 {
-        int j;
-
         /* Tx ring needs a pair of descriptors, the second for the status. */
         for (i = 0; i < TX_RING_SIZE; i++) {
                 j = 2*i;
@@ -805,7 +813,7 @@ static void yellowfin_init_ring(struct net_device *dev)
 }
 #endif
         yp->tx_tail_desc = &yp->tx_status[0];
-        return;
+        return 0;
 }
 
 static int yellowfin_start_xmit(struct sk_buff *skb, struct net_device *dev)