arc_emac: fix potential use after free

Signed-off-by: Eric Dumazet <edumazet@google.com>

skb_tx_timestamp(skb) should be called _before_ TX completion
has a chance to trigger, otherwise it is too late and we access
freed memory.

Fixes: e4f2379db6 ("ethernet/arc/arc_emac - Add new driver")
From: Eric Dumazet <edumazet@google.com>
Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2013-12-19 18:10:40 -08:00 committed by David S. Miller
parent 375679104a
commit 37ec274e97

View file

@ -565,6 +565,8 @@ static int arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
/* Make sure pointer to data buffer is set */
wmb();
skb_tx_timestamp(skb);
*info = cpu_to_le32(FOR_EMAC | FIRST_OR_LAST_MASK | len);
/* Increment index to point to the next BD */
@ -579,8 +581,6 @@ static int arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
arc_reg_set(priv, R_STATUS, TXPL_MASK);
skb_tx_timestamp(skb);
return NETDEV_TX_OK;
}