usb: gadget: eem: fix wrong eem header operation

when skb_clone() or skb_copy_expand() fail,
it should pull skb with lengh indicated by header,
or not it will read network data and check it as header.

Cc: <stable@vger.kernel.org>
Signed-off-by: Linyu Yuan <linyyuan@codeaurora.com>
Link: https://lore.kernel.org/r/20210608233547.3767-1-linyyuan@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/function/f_eem.c b/drivers/usb/gadget/function/f_eem.c
index e6cb384..2cd9942 100644 (file)
--- a/drivers/usb/gadget/function/f_eem.c
+++ b/drivers/usb/gadget/function/f_eem.c
@@ -495,7 +495,7 @@ static int eem_unwrap(struct gether *port,
                        skb2 = skb_clone(skb, GFP_ATOMIC);
                        if (unlikely(!skb2)) {
                                DBG(cdev, "unable to unframe EEM packet\n");
-                               continue;
+                               goto next;
                        }
                        skb_trim(skb2, len - ETH_FCS_LEN);
 
@@ -505,7 +505,7 @@ static int eem_unwrap(struct gether *port,
                                                GFP_ATOMIC);
                        if (unlikely(!skb3)) {
                                dev_kfree_skb_any(skb2);
-                               continue;
+                               goto next;
                        }
                        dev_kfree_skb_any(skb2);
                        skb_queue_tail(list, skb3);