Commit 6bc6895b authored Apr 19, 2017 by Eric Dumazet Committed by David S. Miller Apr 21, 2017

ch9200: 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: 4a476bd6 ("usbnet: New driver for QinHeng CH9200 devices")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent d4ca7359

drivers/net/usb/ch9200.c

+2 −7

Original line number	Diff line number	Diff line
		@@ -254,13 +254,8 @@ static struct sk_buff ch9200_tx_fixup(struct usbnet dev, struct sk_buff *skb,
		tx_overhead = 0x40;

		len = skb->len;
		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;
		}