[PATCH] led: triggers: Fix dereferencing of null pointer

[PATCH] led: triggers: Fix dereferencing of null pointer

[Oleh Kravchenko]

Error was detected by PVS-Studio:
V522 Dereferencing of the null pointer 'led_cdev->trigger' might take place.

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
---
 drivers/leds/led-triggers.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index eff1bda8b520..23963e5cb5d6 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -167,11 +167,11 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
 		trig->deactivate(led_cdev);
 err_activate:
 
-	led_cdev->trigger = NULL;
-	led_cdev->trigger_data = NULL;
 	write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
 	list_del(&led_cdev->trig_list);
 	write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
+	led_cdev->trigger = NULL;
+	led_cdev->trigger_data = NULL;
 	led_set_brightness(led_cdev, LED_OFF);
 	kfree(event);
 
-- 
2.21.0

Re: [PATCH] led: triggers: Fix dereferencing of null pointer

[Jacek Anaszewski]

Hi Oleh,

Thank you for the patch

On 9/3/19 11:18 PM, Oleh Kravchenko wrote:
> Error was detected by PVS-Studio:
> V522 Dereferencing of the null pointer 'led_cdev->trigger' might take place.
> 
> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
> ---
>  drivers/leds/led-triggers.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
> index eff1bda8b520..23963e5cb5d6 100644
> --- a/drivers/leds/led-triggers.c
> +++ b/drivers/leds/led-triggers.c
> @@ -167,11 +167,11 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
>  		trig->deactivate(led_cdev);
>  err_activate:
>  
> -	led_cdev->trigger = NULL;
> -	led_cdev->trigger_data = NULL;
>  	write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
>  	list_del(&led_cdev->trig_list);
>  	write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
> +	led_cdev->trigger = NULL;
> +	led_cdev->trigger_data = NULL;
>  	led_set_brightness(led_cdev, LED_OFF);
>  	kfree(event);
>  
> 

Added tag:

Fixes: 2282e125a406 ("leds: triggers: let struct led_trigger::activate()
return an error code")

and applied.

-- 
Best regards,
Jacek Anaszewski