[PATCH] media: ov5640: fix use of destroyed mutex

[PATCH] media: ov5640: fix use of destroyed mutex

[Tomi Valkeinen]

v4l2_ctrl_handler_free() uses hdl->lock, which in ov5640 driver is set
to sensor's own sensor->lock. In ov5640_remove(), the driver destroys the
sensor->lock first, and then calls v4l2_ctrl_handler_free(), resulting
in the use of the destroyed mutex.

Fix this by calling v4l2_ctrl_handler_free() before mutex_destroy().

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: stable@vger.kernel.org
---
 drivers/media/i2c/ov5640.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index 854031f0b64a..64511de4eea8 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -3104,9 +3104,9 @@ static int ov5640_remove(struct i2c_client *client)
 	struct ov5640_dev *sensor = to_ov5640_dev(sd);
 
 	v4l2_async_unregister_subdev(&sensor->sd);
+	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
 	mutex_destroy(&sensor->lock);
 	media_entity_cleanup(&sensor->sd.entity);
-	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
 
 	return 0;
 }
-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH] media: ov5640: fix use of destroyed mutex

[Laurent Pinchart]

Hi Tomi,

Thank you for the patch.

On Fri, Mar 13, 2020 at 10:22:58AM +0200, Tomi Valkeinen wrote:
> v4l2_ctrl_handler_free() uses hdl->lock, which in ov5640 driver is set
> to sensor's own sensor->lock. In ov5640_remove(), the driver destroys the
> sensor->lock first, and then calls v4l2_ctrl_handler_free(), resulting
> in the use of the destroyed mutex.
> 
> Fix this by calling v4l2_ctrl_handler_free() before mutex_destroy().
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Cc: stable@vger.kernel.org
> ---
>  drivers/media/i2c/ov5640.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index 854031f0b64a..64511de4eea8 100644
> --- a/drivers/media/i2c/ov5640.c
> +++ b/drivers/media/i2c/ov5640.c
> @@ -3104,9 +3104,9 @@ static int ov5640_remove(struct i2c_client *client)
>  	struct ov5640_dev *sensor = to_ov5640_dev(sd);
>  
>  	v4l2_async_unregister_subdev(&sensor->sd);
> +	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
>  	mutex_destroy(&sensor->lock);
>  	media_entity_cleanup(&sensor->sd.entity);
> -	v4l2_ctrl_handler_free(&sensor->ctrls.handler);

While at it, could you move the mutex after media_entity_cleanup() too,
to avoid future problems in case it gets used through that path ?

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

>  
>  	return 0;
>  }

-- 
Regards,

Laurent Pinchart

[PATCH v2] media: ov5640: fix use of destroyed mutex

[Tomi Valkeinen]

v4l2_ctrl_handler_free() uses hdl->lock, which in ov5640 driver is set
to sensor's own sensor->lock. In ov5640_remove(), the driver destroys the
sensor->lock first, and then calls v4l2_ctrl_handler_free(), resulting
in the use of the destroyed mutex.

Fix this by calling moving the mutex_destroy() to the end of the cleanup
sequence, as there's no need to destroy the mutex as early as possible.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: stable@vger.kernel.org
---
 drivers/media/i2c/ov5640.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index 854031f0b64a..2fe4a7ac0592 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -3093,8 +3093,8 @@ static int ov5640_probe(struct i2c_client *client)
 free_ctrls:
 	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
 entity_cleanup:
-	mutex_destroy(&sensor->lock);
 	media_entity_cleanup(&sensor->sd.entity);
+	mutex_destroy(&sensor->lock);
 	return ret;
 }
 
@@ -3104,9 +3104,9 @@ static int ov5640_remove(struct i2c_client *client)
 	struct ov5640_dev *sensor = to_ov5640_dev(sd);
 
 	v4l2_async_unregister_subdev(&sensor->sd);
-	mutex_destroy(&sensor->lock);
 	media_entity_cleanup(&sensor->sd.entity);
 	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
+	mutex_destroy(&sensor->lock);
 
 	return 0;
 }
-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH v2] media: ov5640: fix use of destroyed mutex

[Benoit Parrot]

Reviewed-by: Benoit Parrot <bparrot@ti.com>

On 3/13/20 8:19 AM, Tomi Valkeinen wrote:
> v4l2_ctrl_handler_free() uses hdl->lock, which in ov5640 driver is set
> to sensor's own sensor->lock. In ov5640_remove(), the driver destroys the
> sensor->lock first, and then calls v4l2_ctrl_handler_free(), resulting
> in the use of the destroyed mutex.
> 
> Fix this by calling moving the mutex_destroy() to the end of the cleanup
> sequence, as there's no need to destroy the mutex as early as possible.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: stable@vger.kernel.org
> ---
>  drivers/media/i2c/ov5640.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index 854031f0b64a..2fe4a7ac0592 100644
> --- a/drivers/media/i2c/ov5640.c
> +++ b/drivers/media/i2c/ov5640.c
> @@ -3093,8 +3093,8 @@ static int ov5640_probe(struct i2c_client *client)
>  free_ctrls:
>  	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
>  entity_cleanup:
> -	mutex_destroy(&sensor->lock);
>  	media_entity_cleanup(&sensor->sd.entity);
> +	mutex_destroy(&sensor->lock);
>  	return ret;
>  }
>  
> @@ -3104,9 +3104,9 @@ static int ov5640_remove(struct i2c_client *client)
>  	struct ov5640_dev *sensor = to_ov5640_dev(sd);
>  
>  	v4l2_async_unregister_subdev(&sensor->sd);
> -	mutex_destroy(&sensor->lock);
>  	media_entity_cleanup(&sensor->sd.entity);
>  	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
> +	mutex_destroy(&sensor->lock);
>  
>  	return 0;
>  }
> 

[PATCH v3] media: ov5640: fix use of destroyed mutex

[Tomi Valkeinen]

v4l2_ctrl_handler_free() uses hdl->lock, which in ov5640 driver is set
to sensor's own sensor->lock. In ov5640_remove(), the driver destroys the
sensor->lock first, and then calls v4l2_ctrl_handler_free(), resulting
in the use of the destroyed mutex.

Fix this by calling moving the mutex_destroy() to the end of the cleanup
sequence, as there's no need to destroy the mutex as early as possible.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: stable@vger.kernel.org # v4.14+
Reviewed-by: Benoit Parrot <bparrot@ti.com>
---

Added reviewed-by from Benoit
Added stable version

 drivers/media/i2c/ov5640.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index 854031f0b64a..2fe4a7ac0592 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -3093,8 +3093,8 @@ static int ov5640_probe(struct i2c_client *client)
 free_ctrls:
 	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
 entity_cleanup:
-	mutex_destroy(&sensor->lock);
 	media_entity_cleanup(&sensor->sd.entity);
+	mutex_destroy(&sensor->lock);
 	return ret;
 }
 
@@ -3104,9 +3104,9 @@ static int ov5640_remove(struct i2c_client *client)
 	struct ov5640_dev *sensor = to_ov5640_dev(sd);
 
 	v4l2_async_unregister_subdev(&sensor->sd);
-	mutex_destroy(&sensor->lock);
 	media_entity_cleanup(&sensor->sd.entity);
 	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
+	mutex_destroy(&sensor->lock);
 
 	return 0;
 }
-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki