[PATCH 5.15 476/917] mt76: mt7915: fix hwmon temp sensor mem use-after-free

Greg Kroah-Hartman
2021-11-16T00:32:27Z

From: Ben Greear <greearb@candelatech.com>

[ Upstream commit 0ae3ff5684514d72357240f1033a7494c51f93ed ]

Without this change, garbage is seen in the hwmon name and sensors output
for mt7915 is garbled. It appears that the hwmon logic does not make a
copy of the incoming string, but instead just copies a char* and expects
it to never go away.

Fixes: 33fe9c639c13 ("mt76: mt7915: add thermal sensor device support")
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/mediatek/mt76/mt7915/init.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/init.c b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
index 4798d6344305d..b171027e0cfa8 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
@@ -130,9 +130,12 @@ static int mt7915_thermal_init(struct mt7915_phy *phy)
struct wiphy *wiphy = phy->mt76->hw->wiphy;
struct thermal_cooling_device *cdev;
struct device *hwmon;
+ const char *name;

- cdev = thermal_cooling_device_register(wiphy_name(wiphy), phy,
- &mt7915_thermal_ops);
+ name = devm_kasprintf(&wiphy->dev, GFP_KERNEL, "mt7915_%s",
+ wiphy_name(wiphy));
+
+ cdev = thermal_cooling_device_register(name, phy, &mt7915_thermal_ops);
if (!IS_ERR(cdev)) {
if (sysfs_create_link(&wiphy->dev.kobj, &cdev->device.kobj,
"cooling_device") < 0)
@@ -144,8 +147,7 @@ static int mt7915_thermal_init(struct mt7915_phy *phy)
if (!IS_REACHABLE(CONFIG_HWMON))
return 0;

- hwmon = devm_hwmon_device_register_with_groups(&wiphy->dev,
- wiphy_name(wiphy), phy,
+ hwmon = devm_hwmon_device_register_with_groups(&wiphy->dev, name, phy,
mt7915_hwmon_groups);
if (IS_ERR(hwmon))
return PTR_ERR(hwmon);
--
2.33.0