media: ov5640: fix use of destroyed mutex
Commit Message
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(-)
Comments
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;
> }
@@ -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;
}