power: supply: max14656: fix potential use-before-alloc

[ Upstream commit 0cd0e49711556d2331a06b1117b68dd786cb54d2 ]

Call order on probe():
- max14656_hw_init() enables interrupts on the chip
- devm_request_irq() starts processing interrupts, isr
  could be called immediately
-    isr: schedules delayed work (irq_work)
-    irq_work: calls power_supply_changed()
- devm_power_supply_register() registers the power supply

Depending on timing, it's possible that power_supply_changed()
is called on an unregistered power supply structure.

Fix by registering the power supply before requesting the irq.

Cc: Alexander Kurz <akurz@blala.de>
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/power/supply/max14656_charger_detector.c b/drivers/power/supply/max14656_charger_detector.c
index b91b1d2999dc6d11ca4112ed160957947192843d..d19307f791c68957c4f2851462e00ad4017c138d 100644 (file)
--- a/drivers/power/supply/max14656_charger_detector.c
+++ b/drivers/power/supply/max14656_charger_detector.c
@@ -280,6 +280,13 @@ static int max14656_probe(struct i2c_client *client,
 
        INIT_DELAYED_WORK(&chip->irq_work, max14656_irq_worker);
 
+       chip->detect_psy = devm_power_supply_register(dev,
+                      &chip->psy_desc, &psy_cfg);
+       if (IS_ERR(chip->detect_psy)) {
+               dev_err(dev, "power_supply_register failed\n");
+               return -EINVAL;
+       }
+
        ret = devm_request_irq(dev, chip->irq, max14656_irq,
                               IRQF_TRIGGER_FALLING,
                               MAX14656_NAME, chip);
@@ -289,13 +296,6 @@ static int max14656_probe(struct i2c_client *client,
        }
        enable_irq_wake(chip->irq);
 
-       chip->detect_psy = devm_power_supply_register(dev,
-                      &chip->psy_desc, &psy_cfg);
-       if (IS_ERR(chip->detect_psy)) {
-               dev_err(dev, "power_supply_register failed\n");
-               return -EINVAL;
-       }
-
        schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(2000));
 
        return 0;