4.9-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
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
--- drivers/net/usb/lan78xx.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-)
--- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -2419,14 +2419,9 @@ static struct sk_buff *lan78xx_tx_prep(s { 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)