From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 18 Aug 2010 00:24:43 +0000 (+0000)
Subject: irda: fix a race in irlan_eth_xmit()
X-Git-Tag: v2.6.36-rc3~42^2~9
X-Git-Url: http://bbs.cooldavid.org/git/?a=commitdiff_plain;h=79c5f51c639021f7472591239c3867cee4b9ec02;p=net-next-2.6.git

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>
---

diff --git a/net/irda/irlan/irlan_eth.c b/net/irda/irlan/irlan_eth.c
index 9616c32d107..5bb8353105c 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;