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>
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index f33460c..9c257ff 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2419,14 +2419,9 @@
{
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)