rt2x00: Don't use unitialized rxdesc->size

rxdesc->size is unitialized before the desriptor has been read.
Move the truncation of the sk buffer to the moment all variables
have been initialized.

Signed-off-by: Mattias Nissler <mattias.nissler@gmx.de>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2500usb.c b/drivers/net/wireless/rt2x00/rt2500usb.c
index 86cd9a5eee2b..559131fc6d53 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -1123,13 +1123,10 @@ static void rt2500usb_fill_rxdone(struct queue_entry *entry,
 
         /*
          * Copy descriptor to the available headroom inside the skbuffer.
-         * Remove the original copy by trimming the skbuffer.
          */
         skb_push(entry->skb, offset);
         memcpy(entry->skb->data, rxd, entry->queue->desc_size);
         rxd = (__le32 *)entry->skb->data;
-        skb_pull(entry->skb, offset);
-        skb_trim(entry->skb, rxdesc->size);
 
         /*
          * The descriptor is now aligned to 4 bytes and thus it is
@@ -1155,11 +1152,17 @@ static void rt2500usb_fill_rxdone(struct queue_entry *entry,
         rxdesc->my_bss = !!rt2x00_get_field32(word0, RXD_W0_MY_BSS);
 
         /*
+         * Adjust the skb memory window to the frame boundaries.
+         */
+        skb_pull(entry->skb, offset);
+        skb_trim(entry->skb, rxdesc->size);
+
+        /*
          * Set descriptor and data pointer.
          */
         skbdesc->data = entry->skb->data;
         skbdesc->data_len = rxdesc->size;
-        skbdesc->desc = entry->skb->data - offset;
+        skbdesc->desc = rxd;
         skbdesc->desc_len = entry->queue->desc_size;
 }