irda: fix a race in irlan_eth_xmit()

After skb is queued, its illegal to dereference it.

Cache skb->len into a temporary variable.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/irda/irlan/irlan_eth.c b/net/irda/irlan/irlan_eth.c
index 9616c32d1076..5bb8353105cc 100644
--- a/net/irda/irlan/irlan_eth.c
+++ b/net/irda/irlan/irlan_eth.c
@@ -169,6 +169,7 @@ static netdev_tx_t irlan_eth_xmit(struct sk_buff *skb,
 {
         struct irlan_cb *self = netdev_priv(dev);
         int ret;
+        unsigned int len;
 
         /* skb headroom large enough to contain all IrDA-headers? */
         if ((skb_headroom(skb) < self->max_header_size) || (skb_shared(skb))) {
@@ -188,6 +189,7 @@ static netdev_tx_t irlan_eth_xmit(struct sk_buff *skb,
 
         dev->trans_start = jiffies;
 
+        len = skb->len;
         /* Now queue the packet in the transport layer */
         if (self->use_udata)
                 ret = irttp_udata_request(self->tsap_data, skb);
@@ -209,7 +211,7 @@ static netdev_tx_t irlan_eth_xmit(struct sk_buff *skb,
                 self->stats.tx_dropped++;
         } else {
                 self->stats.tx_packets++;
-                self->stats.tx_bytes += skb->len;
+                self->stats.tx_bytes += len;
         }
 
         return NETDEV_TX_OK;