From aead0ffbf078e0098ca6cfd1625029ff9347b10d Mon Sep 17 00:00:00 2001
From: Eugen Hristev <eugen.hristev@microchip.com>
Date: Wed, 26 Feb 2020 16:28:16 +0100
Subject: [PATCH] media: v4l2-core: fix entity initialization in device_register_subdev
Git-commit: aead0ffbf078e0098ca6cfd1625029ff9347b10d
Patch-mainline: v5.7-rc1
References: bsc#1051510

The entity variable was being initialized in the wrong place, before the
parameters have been checked.
To solve this, completely removed the entity variable and replaced it
with the initialization value : &sd->entity.
This will avoid dereferencing 'sd' pointer before it's being checked if
it's NULL.

Fixes: 61f5db549dde ("[media] v4l: Make v4l2_subdev inherit from media_entity")

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/v4l2-core/v4l2-device.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
index 41da73ce2e98..c69941214bb2 100644
--- a/drivers/media/v4l2-core/v4l2-device.c
+++ b/drivers/media/v4l2-core/v4l2-device.c
@@ -111,9 +111,6 @@ EXPORT_SYMBOL_GPL(v4l2_device_unregister);
 int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
 				struct v4l2_subdev *sd)
 {
-#if defined(CONFIG_MEDIA_CONTROLLER)
-	struct media_entity *entity = &sd->entity;
-#endif
 	int err;
 
 	/* Check for valid input */
@@ -143,7 +140,7 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	/* Register the entity. */
 	if (v4l2_dev->mdev) {
-		err = media_device_register_entity(v4l2_dev->mdev, entity);
+		err = media_device_register_entity(v4l2_dev->mdev, &sd->entity);
 		if (err < 0)
 			goto error_module;
 	}
@@ -163,7 +160,7 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
 
 error_unregister:
 #if defined(CONFIG_MEDIA_CONTROLLER)
-	media_device_unregister_entity(entity);
+	media_device_unregister_entity(&sd->entity);
 #endif
 error_module:
 	if (!sd->owner_v4l2_dev)
-- 
2.16.4