USB: net1080 inherent pad length

The size of struct nc_trailer is inherently the newtailroom pad.


Signed-off-by: David Rientjes <rientjes@google.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 7 insertions, 8 deletions

diff --git a/drivers/usb/net/net1080.c b/drivers/usb/net/net1080.c
index a9b6eeac3e3f..301baa72bac7 100644
--- a/drivers/usb/net/net1080.c
+++ b/drivers/usb/net/net1080.c
@@ -498,25 +498,24 @@ static int net1080_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 static struct sk_buff *
 net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 {
-        int                     padlen;
         struct sk_buff          *skb2;
         struct nc_header        *header = NULL;
         struct nc_trailer       *trailer = NULL;
+        int                     padlen = sizeof (struct nc_trailer);
         int                     len = skb->len;
 
-        padlen = ((len + sizeof (struct nc_header)
-                        + sizeof (struct nc_trailer)) & 0x01) ? 0 : 1;
+        if (!((len + padlen + sizeof (struct nc_header)) & 0x01))
+                padlen++;
         if (!skb_cloned(skb)) {
                 int     headroom = skb_headroom(skb);
                 int     tailroom = skb_tailroom(skb);
 
-                if ((padlen + sizeof (struct nc_trailer)) <= tailroom
-                            && sizeof (struct nc_header) <= headroom)
+                if (padlen <= tailroom &&
+                    sizeof(struct nc_header) <= headroom)
                         /* There's enough head and tail room */
                         goto encapsulate;
 
-                if ((sizeof (struct nc_header) + padlen
-                                        + sizeof (struct nc_trailer)) <
+                if ((sizeof (struct nc_header) + padlen) <
                                 (headroom + tailroom)) {
                         /* There's enough total room, so just readjust */
                         skb->data = memmove(skb->head
@@ -530,7 +529,7 @@ net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
         /* Create a new skb to use with the correct size */
         skb2 = skb_copy_expand(skb,
                                 sizeof (struct nc_header),
-                                sizeof (struct nc_trailer) + padlen,
+                                padlen,
                                 flags);
         dev_kfree_skb_any(skb);
         if (!skb2)