[PATCH 5.13 503/800] mt76: mt7615: fix potential overflow on large shift

[Greg Kroah-Hartman]

From: Ryder Lee <ryder.lee@xxxxxxxxxxxx>

[ Upstream commit 3253f8fddd954aba9ac88ce3c34551dcca505b21 ]

Fix the following static checker warning:
error: undefined (user controlled) shift '(((1))) << (c->omac_idx)'

Fixes: 402a695b1ae6 ("mt76: mt7615: fix CSA notification for DBDC")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/wireless/mediatek/mt76/mt7615/mcu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
index aa42af9ebfd6..ae2191371f51 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
@@ -411,6 +411,9 @@ mt7615_mcu_rx_csa_notify(struct mt7615_dev *dev, struct sk_buff *skb)
 
 	c = (struct mt7615_mcu_csa_notify *)skb->data;
 
+	if (c->omac_idx > EXT_BSSID_MAX)
+		return;
+
 	if (ext_phy && ext_phy->omac_mask & BIT_ULL(c->omac_idx))
 		mphy = dev->mt76.phy2;
 
-- 
2.30.2