[PATCH 04/14] media: ov6650: Fix unverified arguments accepted by .get_fmt()

[Janusz Krzysztofik <jmkrzyszt@gmail.com>]

Commit da298c6d98d5 ("[media] v4l2: replace video op g_mbus_fmt by pad
op get_fmt") converted a former ov6650_g_fmt() video operation callback
to an ov6650_get_fmt() pad operation callback.  However, the function
does not verify correctness of user provided format->which flag and pad
config pointer arguments.  Fix it.

Even if the function never dereferences the pad config pointer argument,
return -EINVAL if it is NULL on V4L2_SUBDEV_FORMAT_TRY.

Fixes: da298c6d98d5 ("[media] v4l2: replace video op g_mbus_fmt by pad op get_fmt")
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Cc: stable@vger.kernel.org
---
 drivers/media/i2c/ov6650.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/media/i2c/ov6650.c b/drivers/media/i2c/ov6650.c
index 3062c9a6c57b..5c1738c5a847 100644
--- a/drivers/media/i2c/ov6650.c
+++ b/drivers/media/i2c/ov6650.c
@@ -515,6 +515,17 @@ static int ov6650_get_fmt(struct v4l2_subdev *sd,
 	if (format->pad)
 		return -EINVAL;
 
+	switch (format->which) {
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		break;
+	case V4L2_SUBDEV_FORMAT_TRY:
+		if (cfg)
+			break;
+		/* fall through */
+	default:
+		return -EINVAL;
+	}
+
 	mf->width	= priv->rect.width >> priv->half_scale;
 	mf->height	= priv->rect.height >> priv->half_scale;
 	mf->code	= priv->code;
-- 
2.21.0