Commit e7b7e0c2 authored Dec 02, 2014 by Eric Dumazet Committed by Greg Kroah-Hartman Dec 16, 2014

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: 71f6d1b3 ("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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 9823d713

drivers/net/ethernet/marvell/mvneta.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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 @@ out:

		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++;