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From:   Ryder Lee <ryder.lee@mediatek.com>
To:     Felix Fietkau <nbd@nbd.name>, <linux-wireless@vger.kernel.org>
CC:     Lorenzo Bianconi <lorenzo.bianconi@redhat.com>,
        Shayne Chen <shayne.chen@mediatek.com>,
        Evelyn Tsai <evelyn.tsai@mediatek.com>,
        <linux-mediatek@lists.infradead.org>,
        Ryder Lee <ryder.lee@mediatek.com>
Subject: [PATCH 1/2] wifi: mt76: mt7996: fix unintended sign extension of mt7996_hw_queue_read()
Date:   Wed, 7 Dec 2022 15:30:04 +0800
Message-ID: <a882942479ff8f20189580a69174202b40210682.1670396836.git.ryder.lee@mediatek.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

In the expression "map[i].qid << 24" starts as u8, but is promoted to
"signed int", then sign-extended to type "unsigned long", which is not
intended. Cast to u32 to avoid the sign extension.

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1527813 ("Integer handling issues")
Fixes: 98686cd21624 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mt7996/debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/debugfs.c b/drivers/net/wireless/mediatek/mt76/mt7996/debugfs.c
index 99b23aef53a5..3d4fbbbcc206 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/debugfs.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/debugfs.c
@@ -457,7 +457,7 @@ mt7996_hw_queue_read(struct seq_file *s, u32 size,
 		if (val & BIT(map[i].index))
 			continue;
 
-		ctrl = BIT(31) | (map[i].pid << 10) | (map[i].qid << 24);
+		ctrl = BIT(31) | (map[i].pid << 10) | ((u32)map[i].qid << 24);
 		mt76_wr(dev, MT_FL_Q0_CTRL, ctrl);
 
 		head = mt76_get_field(dev, MT_FL_Q2_CTRL,
-- 
2.18.0