4.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
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 edumazet@google.com Cc: James Hughes james.hughes@raspberrypi.org Cc: Matthew Garrett mjg59@srcf.ucam.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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);