From: Felix Fietkau nbd@nbd.name
[ Upstream commit 36f7e2b2bb1de86f0072cd49ca93d82b9e8fd894 ]
With the devm API, the unregister happens after the device cleanup is done, after which the struct mt76_dev which contains the led_cdev has already been freed. This leads to a use-after-free bug that can crash the system.
Signed-off-by: Felix Fietkau nbd@nbd.name Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/mediatek/mt76/mac80211.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c index 1a2c143b34d01..7be5806a1c398 100644 --- a/drivers/net/wireless/mediatek/mt76/mac80211.c +++ b/drivers/net/wireless/mediatek/mt76/mac80211.c @@ -105,7 +105,15 @@ static int mt76_led_init(struct mt76_dev *dev) dev->led_al = of_property_read_bool(np, "led-active-low"); }
- return devm_led_classdev_register(dev->dev, &dev->led_cdev); + return led_classdev_register(dev->dev, &dev->led_cdev); +} + +static void mt76_led_cleanup(struct mt76_dev *dev) +{ + if (!dev->led_cdev.brightness_set && !dev->led_cdev.blink_set) + return; + + led_classdev_unregister(&dev->led_cdev); }
static void mt76_init_stream_cap(struct mt76_dev *dev, @@ -360,6 +368,7 @@ void mt76_unregister_device(struct mt76_dev *dev) { struct ieee80211_hw *hw = dev->hw;
+ mt76_led_cleanup(dev); mt76_tx_status_check(dev, NULL, true); ieee80211_unregister_hw(hw); }