Jan 06 2013

88pm860x_battery: Eliminate possible references to released resources 

Author: Julia Lawall <julia.lawall@lip6.fr>

devm_kzalloc should not be followed by kfree, as this results in a double
free.  The problem was found using the following semantic match
(http://coccinelle.lip6.fr/):

// 
@@
expression x,e;
@@
x = devm_kzalloc(...)
... when != x = e
?-kfree(x,...);
// 

Furthermore, in the remove function, the calls to free_irq are moved up to
prevent a possible reference in the interrupt handler to resources freed by
power_supply_unregister.

Signed-off-by: Julia Lawall 
Signed-off-by: Anton Vorontsov 

---
 drivers/power/88pm860x_battery.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)
 
diff --git a/drivers/power/88pm860x_battery.c b/drivers/power/88pm860x_battery.c
index 8bc80b0..d338c1c 100644
--- a/drivers/power/88pm860x_battery.c
+++ b/drivers/power/88pm860x_battery.c
@@ -915,15 +915,13 @@ static int pm860x_battery_probe(struct platform_device *pdev)
 	info->irq_cc = platform_get_irq(pdev, 0);
 	if (info->irq_cc <= 0) {
 		dev_err(&pdev->dev, "No IRQ resource!\n");
-		ret = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 
 	info->irq_batt = platform_get_irq(pdev, 1);
 	if (info->irq_batt <= 0) {
 		dev_err(&pdev->dev, "No IRQ resource!\n");
-		ret = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 
 	info->chip = chip;
@@ -957,7 +955,7 @@ static int pm860x_battery_probe(struct platform_device *pdev)
 
 	ret = power_supply_register(&pdev->dev, &info->battery);
 	if (ret)
-		goto out;
+		return ret;
 	info->battery.dev->parent = &pdev->dev;
 
 	ret = request_threaded_irq(info->irq_cc, NULL,
@@ -984,8 +982,6 @@ out_coulomb:
 	free_irq(info->irq_cc, info);
 out_reg:
 	power_supply_unregister(&info->battery);
-out:
-	kfree(info);
 	return ret;
 }
 
@@ -993,10 +989,9 @@ static int pm860x_battery_remove(struct platform_device *pdev)
 {
 	struct pm860x_battery_info *info = platform_get_drvdata(pdev);
 
-	power_supply_unregister(&info->battery);
 	free_irq(info->irq_batt, info);
 	free_irq(info->irq_cc, info);
-	kfree(info);
+	power_supply_unregister(&info->battery);
 	platform_set_drvdata(pdev, NULL);
 	return 0;
 }

qlambert