3c515: Write outside array bounds

if dev_alloc_skb() fails on the first iteration, a write to
cp->rx_ring[-1] occurs.

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

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/net/3c515.c b/drivers/net/3c515.c
index 3e00fa8ea65f..4a7c32895be5 100644
--- a/drivers/net/3c515.c
+++ b/drivers/net/3c515.c
@@ -832,7 +832,9 @@ static int corkscrew_open(struct net_device *dev)
                         skb_reserve(skb, 2);    /* Align IP on 16 byte boundaries */
                         vp->rx_ring[i].addr = isa_virt_to_bus(skb->data);
                 }
-                vp->rx_ring[i - 1].next = isa_virt_to_bus(&vp->rx_ring[0]);     /* Wrap the ring. */
+                if (i != 0)
+                        vp->rx_ring[i - 1].next =
+                                isa_virt_to_bus(&vp->rx_ring[0]);       /* Wrap the ring. */
                 outl(isa_virt_to_bus(&vp->rx_ring[0]), ioaddr + UpListPtr);
         }
         if (vp->full_bus_master_tx) {   /* Boomerang bus master Tx. */