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From:   greearb@candelatech.com
To:     linux-wireless@vger.kernel.org
Cc:     Ben Greear <greearb@candelatech.com>
Subject: [PATCH v2] mt76: mt7915:  Fix hwmon temp sensor mem use-after-free.
Date:   Fri, 30 Jul 2021 10:38:03 -0700
Message-Id: <20210730173803.24358-1-greearb@candelatech.com>
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From: Ben Greear <greearb@candelatech.com>

Without this change, garbage is seen in the hwmon name
and sensors output for mt7915 is garbled.

With the change:

mt7915-pci-1400
Adapter: PCI adapter
temp1:        +49.0°C

Signed-off-by: Ben Greear <greearb@candelatech.com>
---
v2:  Take ext-phy into account
   and do similar logic for the cooling device logic.

 drivers/net/wireless/mediatek/mt76/mt7915/init.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/init.c b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
index 192e3e190ce1..944b74a807a7 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
@@ -132,8 +132,18 @@ static int mt7915_thermal_init(struct mt7915_phy *phy)
 	struct wiphy *wiphy = phy->mt76->hw->wiphy;
 	struct thermal_cooling_device *cdev;
 	struct device *hwmon;
-
-	cdev = thermal_cooling_device_register(wiphy_name(wiphy), phy,
+	struct mt7915_dev *dev = phy->dev;
+	bool ext_phy = phy != &dev->phy;
+	static const char *prefix_ext = "mt7915_ext";
+	static const char *prefix = "mt7915";
+	const char *my_prefix;
+
+	if (ext_phy)
+		my_prefix = prefix_ext;
+	else
+		my_prefix = prefix;
+
+	cdev = thermal_cooling_device_register(my_prefix, phy,
 					       &mt7915_thermal_ops);
 	if (!IS_ERR(cdev)) {
 		if (sysfs_create_link(&wiphy->dev.kobj, &cdev->device.kobj,
@@ -147,7 +157,7 @@ static int mt7915_thermal_init(struct mt7915_phy *phy)
 		return 0;
 
 	hwmon = devm_hwmon_device_register_with_groups(&wiphy->dev,
-						       wiphy_name(wiphy), phy,
+						       my_prefix, phy,
 						       mt7915_hwmon_groups);
 	if (IS_ERR(hwmon))
 		return PTR_ERR(hwmon);
-- 
2.20.1