[PATCH 6.6] leds: mlxreg: Use devm_mutex_init() for mutex initialization

[PATCH 6.6] leds: mlxreg: Use devm_mutex_init() for mutex initialization

[Bin Lan]

From: George Stark <gnstark@salutedevices.com>

[ Upstream commit efc347b9efee1c2b081f5281d33be4559fa50a16 ]

In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses mutex which was destroyed already
in module's remove() so use devm API instead.

Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240411161032.609544-8-gnstark@salutedevices.com
Signed-off-by: Lee Jones <lee@kernel.org>
[ Resolve minor conflicts to fix CVE-2024-42129 ]
Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
---
 drivers/leds/leds-mlxreg.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/leds/leds-mlxreg.c b/drivers/leds/leds-mlxreg.c
index 39210653acf7..b1510cd32e47 100644
--- a/drivers/leds/leds-mlxreg.c
+++ b/drivers/leds/leds-mlxreg.c
@@ -257,6 +257,7 @@ static int mlxreg_led_probe(struct platform_device *pdev)
 {
 	struct mlxreg_core_platform_data *led_pdata;
 	struct mlxreg_led_priv_data *priv;
+	int err;
 
 	led_pdata = dev_get_platdata(&pdev->dev);
 	if (!led_pdata) {
@@ -268,28 +269,21 @@ static int mlxreg_led_probe(struct platform_device *pdev)
 	if (!priv)
 		return -ENOMEM;
 
-	mutex_init(&priv->access_lock);
+	err = devm_mutex_init(&pdev->dev, &priv->access_lock);
+	if (err)
+		return err;
+
 	priv->pdev = pdev;
 	priv->pdata = led_pdata;
 
 	return mlxreg_led_config(priv);
 }
 
-static int mlxreg_led_remove(struct platform_device *pdev)
-{
-	struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
-
-	mutex_destroy(&priv->access_lock);
-
-	return 0;
-}
-
 static struct platform_driver mlxreg_led_driver = {
 	.driver = {
 	    .name = "leds-mlxreg",
 	},
 	.probe = mlxreg_led_probe,
-	.remove = mlxreg_led_remove,
 };
 
 module_platform_driver(mlxreg_led_driver);
-- 
2.43.0

Re: [PATCH 6.6] leds: mlxreg: Use devm_mutex_init() for mutex initialization

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: efc347b9efee1c2b081f5281d33be4559fa50a16

WARNING: Author mismatch between patch and upstream commit:
Backport author: Bin Lan <bin.lan.cn@windriver.com>
Commit author: George Stark <gnstark@salutedevices.com>


Status in newer kernel trees:
6.11.y | Present (exact SHA1)
6.6.y | Not found

Note: The patch differs from the upstream commit:
---
--- -	2024-11-19 07:43:38.458373754 -0500
+++ /tmp/tmp.8Ym27M0bF0	2024-11-19 07:43:38.452657083 -0500
@@ -1,3 +1,5 @@
+[ Upstream commit efc347b9efee1c2b081f5281d33be4559fa50a16 ]
+
 In this driver LEDs are registered using devm_led_classdev_register()
 so they are automatically unregistered after module's remove() is done.
 led_classdev_unregister() calls module's led_set_brightness() to turn off
@@ -8,15 +10,17 @@
 Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
 Link: https://lore.kernel.org/r/20240411161032.609544-8-gnstark@salutedevices.com
 Signed-off-by: Lee Jones <lee@kernel.org>
+[ Resolve minor conflicts to fix CVE-2024-42129 ]
+Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
 ---
- drivers/leds/leds-mlxreg.c | 14 +++++---------
- 1 file changed, 5 insertions(+), 9 deletions(-)
+ drivers/leds/leds-mlxreg.c | 16 +++++-----------
+ 1 file changed, 5 insertions(+), 11 deletions(-)
 
 diff --git a/drivers/leds/leds-mlxreg.c b/drivers/leds/leds-mlxreg.c
-index 5595788d98d20..1b70de72376cc 100644
+index 39210653acf7..b1510cd32e47 100644
 --- a/drivers/leds/leds-mlxreg.c
 +++ b/drivers/leds/leds-mlxreg.c
-@@ -256,6 +256,7 @@ static int mlxreg_led_probe(struct platform_device *pdev)
+@@ -257,6 +257,7 @@ static int mlxreg_led_probe(struct platform_device *pdev)
  {
  	struct mlxreg_core_platform_data *led_pdata;
  	struct mlxreg_led_priv_data *priv;
@@ -24,7 +28,7 @@
  
  	led_pdata = dev_get_platdata(&pdev->dev);
  	if (!led_pdata) {
-@@ -267,26 +268,21 @@ static int mlxreg_led_probe(struct platform_device *pdev)
+@@ -268,28 +269,21 @@ static int mlxreg_led_probe(struct platform_device *pdev)
  	if (!priv)
  		return -ENOMEM;
  
@@ -39,11 +43,13 @@
  	return mlxreg_led_config(priv);
  }
  
--static void mlxreg_led_remove(struct platform_device *pdev)
+-static int mlxreg_led_remove(struct platform_device *pdev)
 -{
 -	struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
 -
 -	mutex_destroy(&priv->access_lock);
+-
+-	return 0;
 -}
 -
  static struct platform_driver mlxreg_led_driver = {
@@ -51,7 +57,10 @@
  	    .name = "leds-mlxreg",
  	},
  	.probe = mlxreg_led_probe,
--	.remove_new = mlxreg_led_remove,
+-	.remove = mlxreg_led_remove,
  };
  
  module_platform_driver(mlxreg_led_driver);
+-- 
+2.43.0
+
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Failed    |

Build Errors:
Build error for stable/linux-6.6.y: