usbnet: fix oops in usbnet_start_xmit

This patch fixes the bug added in commit v3.1-rc7-1055-gf9b491e
SKB can be NULL at this point, at least for cdc-ncm.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 7d6082160bcc42377a51ba2b8be6f60a37eec093..fae0fbd8bc887a99ca0e068bbc4d06bed884775c 100644 (file)
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1057,7 +1057,8 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
        unsigned long           flags;
        int retval;
 
-       skb_tx_timestamp(skb);
+       if (skb)
+               skb_tx_timestamp(skb);
 
        // some devices want funky USB-level framing, for
        // win32 driver (usually) and/or hardware quirks