[PATCH 3.2 006/164] compal-laptop: Check return value of power_supply_register

[Ben Hutchings]

3.2.70-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>

commit 1915a718b1872edffcb13e5436a9f7302d3d36f0 upstream.

The return value of power_supply_register() call was not checked and
even on error probe() function returned 0. If registering failed then
during unbind the driver tried to unregister power supply which was not
actually registered.

This could lead to memory corruption because power_supply_unregister()
unconditionally cleans up given power supply.

Fix this by checking return status of power_supply_register() call. In
case of failure, clean up sysfs entries and fail the probe.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Fixes: 9be0fcb5ed46 ("compal-laptop: add JHL90, battery & hwmon interface")
Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx>
[bwh: Backported to 3.2: insert the appropriate cleanup code as there is no
 common 'remove' label]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/drivers/platform/x86/compal-laptop.c
+++ b/drivers/platform/x86/compal-laptop.c
@@ -1046,7 +1046,14 @@ static int __devinit compal_probe(struct
 
 	/* Power supply */
 	initialize_power_supply_data(data);
-	power_supply_register(&compal_device->dev, &data->psy);
+	err = power_supply_register(&compal_device->dev, &data->psy);
+	if (err < 0) {
+		hwmon_device_unregister(data->hwmon_dev);
+		sysfs_remove_group(&pdev->dev.kobj,
+				&compal_attribute_group);
+		kfree(data);
+		return err;
+	}
 
 	platform_set_drvdata(pdev, data);
 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/