mv643xx_eth: fix race in trasmit path.

Because the socket buffer is freed in the completion interrupt, it is not
safe to access it after submitting it to the hardware.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index a5d9b1c310b3..1b7d2c1c34b6 100644
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -859,7 +859,7 @@ no_csum:
 static netdev_tx_t mv643xx_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct mv643xx_eth_private *mp = netdev_priv(dev);
-        int queue;
+        int length, queue;
         struct tx_queue *txq;
         struct netdev_queue *nq;
 
@@ -881,10 +881,12 @@ static netdev_tx_t mv643xx_eth_xmit(struct sk_buff *skb, struct net_device *dev)
                 return NETDEV_TX_OK;
         }
 
+        length = skb->len;
+
         if (!txq_submit_skb(txq, skb)) {
                 int entries_left;
 
-                txq->tx_bytes += skb->len;
+                txq->tx_bytes += length;
                 txq->tx_packets++;
 
                 entries_left = txq->tx_ring_size - txq->tx_desc_count;