smsc75xx: use skb_cow_head() to deal with cloned skbs

commit b7c6d26758 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: d0cad87170 ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
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 09:59:21 -07:00
committed by Greg Kroah-Hartman
parent ab4fd7a2dd
commit 7c5015409b

View File

@@ -2205,13 +2205,9 @@ static struct sk_buff *smsc75xx_tx_fixup(struct usbnet *dev,
{
u32 tx_cmd_a, tx_cmd_b;
if (skb_headroom(skb) < SMSC75XX_TX_OVERHEAD) {
struct sk_buff *skb2 =
skb_copy_expand(skb, SMSC75XX_TX_OVERHEAD, 0, flags);
if (skb_cow_head(skb, SMSC75XX_TX_OVERHEAD)) {
dev_kfree_skb_any(skb);
skb = skb2;
if (!skb)
return NULL;
return NULL;
}
tx_cmd_a = (u32)(skb->len & TX_CMD_A_LEN) | TX_CMD_A_FCS;