4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Eric Dumazet <[email protected]> commit 6bc6895bdd6744e0136eaa4a11fbdb20a7db4e40 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: 4a476bd6d1d9 ("usbnet: New driver for QinHeng CH9200 devices") Signed-off-by: Eric Dumazet <[email protected]> Cc: James Hughes <[email protected]> Cc: Matthew Garrett <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Linus Walleij <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/net/usb/ch9200.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) --- a/drivers/net/usb/ch9200.c +++ b/drivers/net/usb/ch9200.c @@ -255,14 +255,9 @@ static struct sk_buff *ch9200_tx_fixup(s tx_overhead = 0x40; len = skb->len; - 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; } __skb_push(skb, tx_overhead);
