net: mvneta: fix race condition in mvneta_tx()

[ Upstream commit 5f478b41033606d325e420df693162e2524c2b94 ]

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: 71f6d1b31fb1 ("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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 0e38db6469fb7940cd2e85088feee9b026a7903d..9c66d3168911be4dfc0c25caba4d4f9fb75102ff 100644 (file)
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -1524,6 +1524,7 @@ static int mvneta_tx(struct sk_buff *skb, struct net_device *dev)
        struct mvneta_tx_queue *txq = &pp->txqs[txq_id];
        struct mvneta_tx_desc *tx_desc;
        struct netdev_queue *nq;
+       int len = skb->len;
        int frags = 0;
        u32 tx_cmd;
 
@@ -1584,7 +1585,7 @@ out:
        if (frags > 0) {
                u64_stats_update_begin(&pp->tx_stats.syncp);
                pp->tx_stats.packets++;
-               pp->tx_stats.bytes += skb->len;
+               pp->tx_stats.bytes += len;
                u64_stats_update_end(&pp->tx_stats.syncp);
 
        } else {