[PATCH 05/14] media: ov6650: Fix unverified arguments accepted by .enum_mbus_code()

[Janusz Krzysztofik <jmkrzyszt@gmail.com>]

Commit ebcff5fce6b1 ("[media] v4l2: replace enum_mbus_fmt by
enum_mbus_code") converted a former ov6650_enum_fmt() video operation
callback to an ov6650_enum_mbus_fmt() pad operation callback.  However,
the function dees not verify correctness of code->which flag and pad
config pointer arguments.  Fix it.

Even if the function has no need to dereference the pad config pointer
argument, return -EINVAL if it is NULL on V4L2_SUBDEV_FORMAT_TRY.

Fixes: ebcff5fce6b1 ("[media] v4l2: replace enum_mbus_fmt by enum_mbus_code")
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Cc: stable@vger.kernel.org
---
 drivers/media/i2c/ov6650.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov6650.c b/drivers/media/i2c/ov6650.c
index 5c1738c5a847..d72fcf56930a 100644
--- a/drivers/media/i2c/ov6650.c
+++ b/drivers/media/i2c/ov6650.c
@@ -737,7 +737,21 @@ static int ov6650_enum_mbus_code(struct v4l2_subdev *sd,
 		struct v4l2_subdev_pad_config *cfg,
 		struct v4l2_subdev_mbus_code_enum *code)
 {
-	if (code->pad || code->index >= ARRAY_SIZE(ov6650_codes))
+	if (code->pad)
+		return -EINVAL;
+
+	switch (code->which) {
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		break;
+	case V4L2_SUBDEV_FORMAT_TRY:
+		if (cfg)
+			break;
+		/* fall through */
+	default:
+		return -EINVAL;
+	}
+
+	if (code->index >= ARRAY_SIZE(ov6650_codes))
 		return -EINVAL;
 
 	code->code = ov6650_codes[code->index];
-- 
2.21.0