Commit b7c6d267 authored Apr 19, 2017 by Eric Dumazet Committed by David S. Miller Apr 21, 2017

smsc75xx: use skb_cow_head() to deal with cloned skbs



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: d0cad871 ("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>

parent 95b9b88d

drivers/net/usb/smsc75xx.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -2203,12 +2203,8 @@ 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;
		}