media: vim2m: Register video device after setting up internals

commit cf7f34777a5b4100a3a44ff95f3d949c62892bdd upstream.

Prevent NULL (or close to NULL) pointer dereference in various places by
registering the video device only when the V4L2 m2m framework has been set
up.

Fixes: commit 96d8eab5d0a1 ("V4L/DVB: [v5,2/2] v4l: Add a mem-to-mem videobuf framework test device")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/platform/vim2m.c b/drivers/media/platform/vim2m.c
index 8d6b09623d884d09d515c240d5cf3a81fb00fc86..02f5bc82ba46b7ad6cecd767bb00242afe7683f5 100644 (file)
--- a/drivers/media/platform/vim2m.c
+++ b/drivers/media/platform/vim2m.c
@@ -1333,12 +1333,6 @@ static int vim2m_probe(struct platform_device *pdev)
        vfd->lock = &dev->dev_mutex;
        vfd->v4l2_dev = &dev->v4l2_dev;
 
-       ret = video_register_device(vfd, VFL_TYPE_GRABBER, 0);
-       if (ret) {
-               v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");
-               goto error_v4l2;
-       }
-
        video_set_drvdata(vfd, dev);
        v4l2_info(&dev->v4l2_dev,
                  "Device registered as /dev/video%d\n", vfd->num);
@@ -1353,6 +1347,12 @@ static int vim2m_probe(struct platform_device *pdev)
                goto error_dev;
        }
 
+       ret = video_register_device(vfd, VFL_TYPE_GRABBER, 0);
+       if (ret) {
+               v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");
+               goto error_m2m;
+       }
+
 #ifdef CONFIG_MEDIA_CONTROLLER
        dev->mdev.dev = &pdev->dev;
        strscpy(dev->mdev.model, "vim2m", sizeof(dev->mdev.model));
@@ -1366,7 +1366,7 @@ static int vim2m_probe(struct platform_device *pdev)
                                                 MEDIA_ENT_F_PROC_VIDEO_SCALER);
        if (ret) {
                v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem media controller\n");
-               goto error_dev;
+               goto error_v4l2;
        }
 
        ret = media_device_register(&dev->mdev);
@@ -1381,11 +1381,13 @@ static int vim2m_probe(struct platform_device *pdev)
 error_m2m_mc:
        v4l2_m2m_unregister_media_controller(dev->m2m_dev);
 #endif
-error_dev:
+error_v4l2:
        video_unregister_device(&dev->vfd);
        /* vim2m_device_release called by video_unregister_device to release various objects */
        return ret;
-error_v4l2:
+error_m2m:
+       v4l2_m2m_release(dev->m2m_dev);
+error_dev:
        v4l2_device_unregister(&dev->v4l2_dev);
 error_free:
        kfree(dev);