[PATCH -next 1/2] wifi: mt76: mt7996: fix overflows seen when writing limit attributes

From: xueqin Luo
Date: Sun Dec 01 2024 - 22:20:04 EST


DIV_ROUND_CLOSEST() after kstrtoul() results in an overflow if a large
number such as 18446744073709551615 is provided by the user.
Fix it by reordering clamp_val() and DIV_ROUND_CLOSEST() operations.
This commit was inspired by commit: 57ee12b6c514.

Fixes: 6879b2e94172 ("wifi: mt76: mt7996: add thermal sensor device support")
Signed-off-by: xueqin Luo <luoxueqin@xxxxxxxxxx>
---
drivers/net/wireless/mediatek/mt76/mt7996/init.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/init.c b/drivers/net/wireless/mediatek/mt76/mt7996/init.c
index 5e96973226bb..3a175222f8ba 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/init.c
@@ -85,7 +85,7 @@ static ssize_t mt7996_thermal_temp_store(struct device *dev,
return ret;

mutex_lock(&phy->dev->mt76.mutex);
- val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 40, 130);
+ val = DIV_ROUND_CLOSEST(clamp_val(val, 40 * 1000, 130 * 1000), 1000);

/* add a safety margin ~10 */
if ((i - 1 == MT7996_CRIT_TEMP_IDX &&
--
2.34.1