4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
commit b7c6d2675899cfff0180412c63fc9cbd5bacdb4d 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: d0cad871703b ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter 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/smsc75xx.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c
@@ -2193,13 +2193,9 @@ static struct sk_buff *smsc75xx_tx_fixup
{
u32 tx_cmd_a, tx_cmd_b;
- if (skb_headroom(skb) < SMSC75XX_TX_OVERHEAD) {
- struct sk_buff *skb2 =
- skb_copy_expand(skb, SMSC75XX_TX_OVERHEAD, 0, flags);
+ if (skb_cow_head(skb, SMSC75XX_TX_OVERHEAD)) {
dev_kfree_skb_any(skb);
- skb = skb2;
- if (!skb)
- return NULL;
+ return NULL;
}
tx_cmd_a = (u32)(skb->len & TX_CMD_A_LEN) | TX_CMD_A_FCS;