isdn: hfc_usb: Fix read buffer overflow
Check whether index is within bounds before testing the element.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/hisax/hfc_usb.c b/drivers/isdn/hisax/hfc_usb.c
index 9de5420..a420b64 100644
--- a/drivers/isdn/hisax/hfc_usb.c
+++ b/drivers/isdn/hisax/hfc_usb.c
@@ -817,8 +817,8 @@
}
/* 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,
