diff --git a/net/mac80211/airtime.c b/net/mac80211/airtime.c
index 26d2f8ba7029..758ef63669e7 100644
--- a/net/mac80211/airtime.c
+++ b/net/mac80211/airtime.c
@@ -457,6 +457,9 @@ static u32 ieee80211_get_rate_duration(struct ieee80211_hw *hw,
 			 (status->encoding == RX_ENC_HE && streams > 8)))
 		return 0;
 
+	if (idx >= MCS_GROUP_RATES)
+		return 0;
+
 	duration = airtime_mcs_groups[group].duration[idx];
 	duration <<= airtime_mcs_groups[group].shift;
 	*overhead = 36 + (streams << 2);