Commit 0ae3bc11 authored Apr 19, 2017 by James Hughes Committed by Greg Kroah-Hartman Feb 20, 2019

smsc95xx: Use skb_cow_head to deal with cloned skbs



commit e9156cd26a495a18706e796f02a81fee41ec14f4 upstream.

The driver was failing to check that the SKB wasn't cloned
before adding checksum data.
Replace existing handling to extend/copy the header buffer
with skb_cow_head.

Signed-off-by: James Hughes <james.hughes@raspberrypi.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Woojung Huh <Woojung.Huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 5b3b651f

drivers/net/usb/smsc95xx.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -2011,12 +2011,12 @@ static struct sk_buff smsc95xx_tx_fixup(struct usbnet dev,
		/* We do not advertise SG, so skbs should be already linearized */
		BUG_ON(skb_shinfo(skb)->nr_frags);

		if (skb_headroom(skb) < overhead) {
		struct sk_buff *skb2 = skb_copy_expand(skb,
		overhead, 0, flags);
		/* Make writable and expand header space by overhead if required */
		if (skb_cow_head(skb, overhead)) {
		/* Must deallocate here as returning NULL to indicate error
		* means the skb won't be deallocated in the caller.
		*/
		dev_kfree_skb_any(skb);
		skb = skb2;
		if (!skb)
		return NULL;
		}