Subject: [PATCH AUTOSEL 5.4 324/350] mt76: fix possible out-of-bound access in mt7615_fill_txs/mt7603_fill_txs

From: Sasha Levin <[email-masked]>
Date: Tue, 10 Dec 2019 16:07:09 -0500

From: Lorenzo Bianconi <[email-masked]>

[ Upstream commit e8b970c8e367e85fab9b8ac4f36080e5d653c38e ]

Fix possible out-of-bound access of status rates array in
mt7615_fill_txs/mt7603_fill_txs routines

Fixes: c5211e997eca ("mt76: mt7603: rework and fix tx status reporting")
Fixes: 4af81f02b49c ("mt76: mt7615: sync with mt7603 rate control changes")
Signed-off-by: Lorenzo Bianconi <[email-masked]>
Signed-off-by: Felix Fietkau <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/wireless/mediatek/mt76/mt7603/mac.c | 4 +++-
 drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7603/mac.c b/drivers/net/wireless/mediatek/mt76/mt7603/mac.c
index c328192307c48..ff3f3d98b6252 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7603/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7603/mac.c
@@ -1032,8 +1032,10 @@ mt7603_fill_txs(struct mt7603_dev *dev, struct mt7603_sta *sta,
 		if (idx && (cur_rate->idx != info->status.rates[i].idx ||
 			    cur_rate->flags != info->status.rates[i].flags)) {
 			i++;
-			if (i == ARRAY_SIZE(info->status.rates))
+			if (i == ARRAY_SIZE(info->status.rates)) {
+				i--;
 				break;
+			}
 
 			info->status.rates[i] = *cur_rate;
 			info->status.rates[i].count = 0;
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
index e07ce2c100133..111e38ff954a2 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
@@ -914,8 +914,10 @@ static bool mt7615_fill_txs(struct mt7615_dev *dev, struct mt7615_sta *sta,
 		if (idx && (cur_rate->idx != info->status.rates[i].idx ||
 			    cur_rate->flags != info->status.rates[i].flags)) {
 			i++;
-			if (i == ARRAY_SIZE(info->status.rates))
+			if (i == ARRAY_SIZE(info->status.rates)) {
+				i--;
 				break;
+			}
 
 			info->status.rates[i] = *cur_rate;
 			info->status.rates[i].count = 0;
-- 
2.20.1