[RFT PATCH v3 1/2] compal-laptop: Fix leaking hwmon device

[RFT PATCH v3 1/2] compal-laptop: Fix leaking hwmon device

[Krzysztof Kozlowski]

The commit c2be45f09bb0 ("compal-laptop: Use
devm_hwmon_device_register_with_groups") wanted to change the
registering of hwmon device to resource-managed version. It mostly did
it except the main thing - it forgot to use devm-like function so the
hwmon device leaked after device removal or probe failure.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: c2be45f09bb0 ("compal-laptop: Use devm_hwmon_device_register_with_groups")
Cc: <stable@vger.kernel.org>

---
Changes since v2:
1. None.

Changes since v1:
1. New patch.
---
 drivers/platform/x86/compal-laptop.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/compal-laptop.c b/drivers/platform/x86/compal-laptop.c
index 15c0fab2bfa1..eb9885e7fb0e 100644
--- a/drivers/platform/x86/compal-laptop.c
+++ b/drivers/platform/x86/compal-laptop.c
@@ -1026,9 +1026,9 @@ static int compal_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
-	hwmon_dev = hwmon_device_register_with_groups(&pdev->dev,
-						      "compal", data,
-						      compal_hwmon_groups);
+	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
+							   "compal", data,
+							   compal_hwmon_groups);
 	if (IS_ERR(hwmon_dev)) {
 		err = PTR_ERR(hwmon_dev);
 		goto remove;
-- 
1.9.1

[RFT PATCH v3 2/2] compal-laptop: Check return value of power_supply_register

[Krzysztof Kozlowski]

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@samsung.com>
Fixes: 9be0fcb5ed46 ("compal-laptop: add JHL90, battery & hwmon interface")
Cc: <stable@vger.kernel.org>

---
Changes since v2:
1. Remove FIXME note.

Changes since v1:
1. Don't unregister hwmon device because previous patch solves this by
   using devm-like function.
---
 drivers/platform/x86/compal-laptop.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/compal-laptop.c b/drivers/platform/x86/compal-laptop.c
index eb9885e7fb0e..bceb30b539f3 100644
--- a/drivers/platform/x86/compal-laptop.c
+++ b/drivers/platform/x86/compal-laptop.c
@@ -1036,7 +1036,9 @@ static int compal_probe(struct platform_device *pdev)
 
 	/* 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)
+		goto remove;
 
 	platform_set_drvdata(pdev, data);
 
-- 
1.9.1

Re: [RFT PATCH v3 1/2] compal-laptop: Fix leaking hwmon device

[Guenter Roeck]

On Fri, Feb 20, 2015 at 02:13:34PM +0100, Krzysztof Kozlowski wrote:
> The commit c2be45f09bb0 ("compal-laptop: Use
> devm_hwmon_device_register_with_groups") wanted to change the
> registering of hwmon device to resource-managed version. It mostly did
> it except the main thing - it forgot to use devm-like function so the
> hwmon device leaked after device removal or probe failure.
> 
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Fixes: c2be45f09bb0 ("compal-laptop: Use devm_hwmon_device_register_with_groups")
> Cc: <stable@vger.kernel.org>

Acked-by: Guenter Roeck <linux@roeck-us.net>

Guenter

Re: [RFT PATCH v3 1/2] compal-laptop: Fix leaking hwmon device

[Darren Hart]

On Fri, Feb 20, 2015 at 02:13:34PM +0100, Krzysztof Kozlowski wrote:
> The commit c2be45f09bb0 ("compal-laptop: Use
> devm_hwmon_device_register_with_groups") wanted to change the
> registering of hwmon device to resource-managed version. It mostly did
> it except the main thing - it forgot to use devm-like function so the
> hwmon device leaked after device removal or probe failure.
> 
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Fixes: c2be45f09bb0 ("compal-laptop: Use devm_hwmon_device_register_with_groups")
> Cc: <stable@vger.kernel.org>

Acked-by: Darren Hart <dvhart@linux.intel.com>

(Assuming this is going through Sebastien's tree)

-- 
Darren Hart
Intel Open Source Technology Center

Re: [RFT PATCH v3 2/2] compal-laptop: Check return value of power_supply_register

[Darren Hart]

On Fri, Feb 20, 2015 at 02:13:35PM +0100, Krzysztof Kozlowski wrote:
> 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@samsung.com>
> Fixes: 9be0fcb5ed46 ("compal-laptop: add JHL90, battery & hwmon interface")
> Cc: <stable@vger.kernel.org>

Acked-by: Darren Hart <dvhart@linux.intel.com>

-- 
Darren Hart
Intel Open Source Technology Center