mac80211: off by one in mcs mask handling

"ridx" is used as an index into the mcs_mask[] array which has
IEEE80211_HT_MCS_MASK_LEN elements.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/rate.c

@@ -324,7 +324,7 @@ static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
 	rbit = rate->idx % 8;
 
 	/* sanity check */
-	if (ridx < 0 || ridx > IEEE80211_HT_MCS_MASK_LEN)
+	if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 		return false;
 
 	/* See whether the selected rate or anything below it is allowed. */

net/wireless/nl80211.c

@@ -5410,7 +5410,7 @@ static bool ht_rateset_to_mask(struct ieee80211_supported_band *sband,
 		rbit = BIT(rates[i] % 8);
 
 		/* check validity */
-		if ((ridx < 0) || (ridx > IEEE80211_HT_MCS_MASK_LEN))
+		if ((ridx < 0) || (ridx >= IEEE80211_HT_MCS_MASK_LEN))
 			return false;
 
 		/* check availability */