[PATCH] media: uvcvideo: Fix a memory leak in error handling code in 'uvc_gpio_parse()'

[PATCH] media: uvcvideo: Fix a memory leak in error handling code in 'uvc_gpio_parse()'

[Christophe JAILLET]

Memory allocated in 'uvc_alloc_entity()' should be freed if an error
occurs after it.

Reorder the code in order to avoid the leak.

Fixes: 2886477ff987 ("media: uvcvideo: Implement UVC_EXT_GPIO_UNIT")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/media/usb/uvc/uvc_driver.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index b1b055784f8d..a4c45424ba7e 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1533,10 +1533,6 @@ static int uvc_gpio_parse(struct uvc_device *dev)
 	if (IS_ERR_OR_NULL(gpio_privacy))
 		return PTR_ERR_OR_ZERO(gpio_privacy);
 
-	unit = uvc_alloc_entity(UVC_EXT_GPIO_UNIT, UVC_EXT_GPIO_UNIT_ID, 0, 1);
-	if (!unit)
-		return -ENOMEM;
-
 	irq = gpiod_to_irq(gpio_privacy);
 	if (irq < 0) {
 		if (irq != EPROBE_DEFER)
@@ -1545,6 +1541,10 @@ static int uvc_gpio_parse(struct uvc_device *dev)
 		return irq;
 	}
 
+	unit = uvc_alloc_entity(UVC_EXT_GPIO_UNIT, UVC_EXT_GPIO_UNIT_ID, 0, 1);
+	if (!unit)
+		return -ENOMEM;
+
 	unit->gpio.gpio_privacy = gpio_privacy;
 	unit->gpio.irq = irq;
 	unit->gpio.bControlSize = 1;
-- 
2.30.2

Re: [PATCH] media: uvcvideo: Fix a memory leak in error handling code in 'uvc_gpio_parse()'

[Ricardo Ribalda]

Hi Christophe

Indeed, there is a bug, uvc_delete will not free the entity because it
has not been added yet.

Thanks for catching it up.

Reviewed by: Ricardo Ribalda <ribalda@chromium.org>

On Sat, 4 Sept 2021 at 08:20, Christophe JAILLET
<christophe.jaillet@wanadoo.fr> wrote:
>
> Memory allocated in 'uvc_alloc_entity()' should be freed if an error
> occurs after it.
>
> Reorder the code in order to avoid the leak.
>
> Fixes: 2886477ff987 ("media: uvcvideo: Implement UVC_EXT_GPIO_UNIT")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
>  drivers/media/usb/uvc/uvc_driver.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index b1b055784f8d..a4c45424ba7e 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -1533,10 +1533,6 @@ static int uvc_gpio_parse(struct uvc_device *dev)
>         if (IS_ERR_OR_NULL(gpio_privacy))
>                 return PTR_ERR_OR_ZERO(gpio_privacy);
>
> -       unit = uvc_alloc_entity(UVC_EXT_GPIO_UNIT, UVC_EXT_GPIO_UNIT_ID, 0, 1);
> -       if (!unit)
> -               return -ENOMEM;
> -
>         irq = gpiod_to_irq(gpio_privacy);
>         if (irq < 0) {
>                 if (irq != EPROBE_DEFER)
> @@ -1545,6 +1541,10 @@ static int uvc_gpio_parse(struct uvc_device *dev)
>                 return irq;
>         }
>
> +       unit = uvc_alloc_entity(UVC_EXT_GPIO_UNIT, UVC_EXT_GPIO_UNIT_ID, 0, 1);
> +       if (!unit)
> +               return -ENOMEM;
> +
>         unit->gpio.gpio_privacy = gpio_privacy;
>         unit->gpio.irq = irq;
>         unit->gpio.bControlSize = 1;
> --
> 2.30.2
>


-- 
Ricardo Ribalda