From 273caa260035c03d89ad63d72d8cd3d9e5c5e3f1 Mon Sep 17 00:00:00 2001
From: Hans Verkuil <hansverk@cisco.com>
Date: Tue, 30 Jan 2018 10:18:32 -0500
Subject: [PATCH] media: v4l2-compat-ioctl32.c: make ctrl_is_pointer work for subdevs
Git-commit: 273caa260035c03d89ad63d72d8cd3d9e5c5e3f1
Patch-mainline: v4.16-rc1
References: CVE-2017-13166,bsc#1072865

If the device is of type VFL_TYPE_SUBDEV then vdev->ioctl_ops
is NULL so the 'if (!ops->vidioc_query_ext_ctrl)' check would crash.
Add a test for !ops to the condition.

All sub-devices that have controls will use the control framework,
so they do not have an equivalent to ops->vidioc_query_ext_ctrl.
Returning false if ops is NULL is the correct thing to do here.

Fixes: b8c601e8af ("v4l2-compat-ioctl32.c: fix ctrl_is_pointer")

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: <stable@vger.kernel.org>      # for v4.15 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -766,7 +766,7 @@ static inline bool ctrl_is_pointer(struc
 		return ctrl && ctrl->is_ptr;
 	}
 
-	if (!ops->vidioc_query_ext_ctrl)
+	if (!ops || !ops->vidioc_query_ext_ctrl)
 		return false;
 
 	return !ops->vidioc_query_ext_ctrl(file, fh, &qec) &&