[3.16.y-ckt stable] Patch "power_supply: twl4030_madc: Check return value of power_supply_register" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    power_supply: twl4030_madc: Check return value of power_supply_register

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt11.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 585a8e52b5f1a0acbda0c637b8db3ed650f39c3c Mon Sep 17 00:00:00 2001
From: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Date: Fri, 20 Feb 2015 14:32:22 +0100
Subject: power_supply: twl4030_madc: Check return value of
 power_supply_register

commit 68c3ed6fa7e0d69529ced772d650ab128916a81d 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.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Fixes: da0a00ebc239 ("power: Add twl4030_madc battery driver.")
Signed-off-by: Sebastian Reichel <sre at kernel.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/power/twl4030_madc_battery.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/power/twl4030_madc_battery.c b/drivers/power/twl4030_madc_battery.c
index 7ef445a6cfa6..cf907609ec49 100644
--- a/drivers/power/twl4030_madc_battery.c
+++ b/drivers/power/twl4030_madc_battery.c
@@ -192,6 +192,7 @@ static int twl4030_madc_battery_probe(struct platform_device *pdev)
 {
 	struct twl4030_madc_battery *twl4030_madc_bat;
 	struct twl4030_madc_bat_platform_data *pdata = pdev->dev.platform_data;
+	int ret = 0;

 	twl4030_madc_bat = kzalloc(sizeof(*twl4030_madc_bat), GFP_KERNEL);
 	if (!twl4030_madc_bat)
@@ -216,9 +217,11 @@ static int twl4030_madc_battery_probe(struct platform_device *pdev)

 	twl4030_madc_bat->pdata = pdata;
 	platform_set_drvdata(pdev, twl4030_madc_bat);
-	power_supply_register(&pdev->dev, &twl4030_madc_bat->psy);
+	ret = power_supply_register(&pdev->dev, &twl4030_madc_bat->psy);
+	if (ret < 0)
+		kfree(twl4030_madc_bat);

-	return 0;
+	return ret;
 }

 static int twl4030_madc_battery_remove(struct platform_device *pdev)