From 542bcc549379e43c1de75a510ea4eb8b9badd918 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 19 Apr 2017 09:59:24 -0700 Subject: [PATCH] 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 Cc: James Hughes Cc: Woojung Huh Signed-off-by: David S. Miller Signed-off-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/lan78xx.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c index f33460cec79f..9c257ffedb15 100644 --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -2419,14 +2419,9 @@ static struct sk_buff *lan78xx_tx_prep(struct lan78xx_net *dev, { 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) -- 2.17.1