4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet <edumazet@xxxxxxxxxx> commit a9e840a2081ed28c2b7caa6a9a0041c950b3c37d 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: cc28a20e77b2 ("introduce cx82310_eth: Conexant CX82310-based ADSL router USB ethernet driver") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: James Hughes <james.hughes@xxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/usb/cx82310_eth.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/drivers/net/usb/cx82310_eth.c +++ b/drivers/net/usb/cx82310_eth.c @@ -293,12 +293,9 @@ static struct sk_buff *cx82310_tx_fixup( { int len = skb->len; - if (skb_headroom(skb) < 2) { - struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags); + if (skb_cow_head(skb, 2)) { dev_kfree_skb_any(skb); - skb = skb2; - if (!skb) - return NULL; + return NULL; } skb_push(skb, 2);