[patch 2/3] hfc_usb: fix read buffer overflow

From: Roel Kluin <redacted>

Check whether index is within bounds before testing the element.

Signed-off-by: Roel Kluin <redacted>
Cc: Karsten Keil <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/isdn/hisax/hfc_usb.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN drivers/isdn/hisax/hfc_usb.c~hfc_usb-fix-read-buffer-overflow drivers/isdn/hisax/hfc_usb.c

--- a/drivers/isdn/hisax/hfc_usb.c~hfc_usb-fix-read-buffer-overflow
+++ a/drivers/isdn/hisax/hfc_usb.c

@@ -817,8 +817,8 @@ collect_rx_frame(usb_fifo * fifo, __u8 *
 	}
 	/* we have a complete hdlc packet */
 	if (finish) {
-		if ((!fifo->skbuff->data[fifo->skbuff->len - 1])
-		    && (fifo->skbuff->len > 3)) {
+		if (fifo->skbuff->len > 3 &&
+				!fifo->skbuff->data[fifo->skbuff->len - 1]) {
 
 			if (fifon == HFCUSB_D_RX) {
 				DBG(HFCUSB_DBG_DCHANNEL,

_