net: mvneta: fix race condition in mvneta_tx()

mvneta_tx() dereferences skb to get skb->len too late,
as hardware might have completed the transmit and TX completion
could have freed the skb from another cpu.

Fixes: 71f6d1b31f ("net: mvneta: replace Tx timer with a real interrupt")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2014-12-02 04:30:59 -08:00 committed by David S. Miller
parent aebea2ba0f
commit 5f478b4103

View File

@ -1721,6 +1721,7 @@ static int mvneta_tx(struct sk_buff *skb, struct net_device *dev)
u16 txq_id = skb_get_queue_mapping(skb);
struct mvneta_tx_queue *txq = &pp->txqs[txq_id];
struct mvneta_tx_desc *tx_desc;
int len = skb->len;
int frags = 0;
u32 tx_cmd;
@ -1788,7 +1789,7 @@ static int mvneta_tx(struct sk_buff *skb, struct net_device *dev)
u64_stats_update_begin(&stats->syncp);
stats->tx_packets++;
stats->tx_bytes += skb->len;
stats->tx_bytes += len;
u64_stats_update_end(&stats->syncp);
} else {
dev->stats.tx_dropped++;