[PATCH 4.9 014/171] nl80211: Fix possible Spectre-v1 for NL80211_TXRATE_HT

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 30fe6d50eb088783c8729c7d930f65296b2b3fa7 ]

Use array_index_nospec() to sanitize ridx with respect to speculation.

Signed-off-by: Masashi Honma <masashi.honma@xxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/wireless/nl80211.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0e91ec49d3da..549d0a4083b3 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3422,6 +3422,7 @@ static bool ht_rateset_to_mask(struct ieee80211_supported_band *sband,
 			return false;
 
 		/* check availability */
+		ridx = array_index_nospec(ridx, IEEE80211_HT_MCS_MASK_LEN);
 		if (sband->ht_cap.mcs.rx_mask[ridx] & rbit)
 			mcs[ridx] |= rbit;
 		else
-- 
2.17.1