lan78xx: use skb_cow_head() to deal with cloned skbs

commit d4ca73591916b760478d2b04334d5dcadc028e9c upstream.

We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.

skb_cow_head() is the proper helper to deal with this.

Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Cc: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric Dumazet 2017-04-19 09:59:24 -07:00 committed by Greg Kroah-Hartman
parent ad196359a6
commit efca4f4694

View File

@ -2050,14 +2050,9 @@ static struct sk_buff *lan78xx_tx_prep(struct lan78xx_net *dev,
{
u32 tx_cmd_a, tx_cmd_b;
if (skb_headroom(skb) < TX_OVERHEAD) {
struct sk_buff *skb2;
skb2 = skb_copy_expand(skb, TX_OVERHEAD, 0, flags);
if (skb_cow_head(skb, TX_OVERHEAD)) {
dev_kfree_skb_any(skb);
skb = skb2;
if (!skb)
return NULL;
return NULL;
}
if (lan78xx_linearize(skb) < 0)