usb: gadget: function: f_eem: socket buffer may be NULL

In eth_start_xmit, the socket buffer may be NULL. So, add NULL pointer
check at .wrap API.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/usb/gadget/function/f_eem.c b/drivers/usb/gadget/function/f_eem.c
index d58bfc32be9e..8741fd740174 100644
--- a/drivers/usb/gadget/function/f_eem.c
+++ b/drivers/usb/gadget/function/f_eem.c
@@ -341,11 +341,15 @@ static struct sk_buff *eem_wrap(struct gether *port, struct sk_buff *skb)
 {
         struct sk_buff  *skb2 = NULL;
         struct usb_ep   *in = port->in_ep;
-        int             padlen = 0;
+        int             headroom, tailroom, padlen = 0;
         u16             len = skb->len;
 
-        int headroom = skb_headroom(skb);
-        int tailroom = skb_tailroom(skb);
+        if (!skb)
+                return NULL;
+
+        len = skb->len;
+        headroom = skb_headroom(skb);
+        tailroom = skb_tailroom(skb);
 
         /* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0,
          * stick two bytes of zero-length EEM packet on the end.