nl80211: Fix possible Spectre-v1 for NL80211_TXRATE_HT

[ Upstream commit 30fe6d50eb088783c8729c7d930f65296b2b3fa7 ]

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

Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0e91ec49d3da1158719de923b4b88f32981bc5ea..549d0a4083b34975689cfd28d0a55e2ed0b68319 100644 (file)
--- 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