From 2cac7cbfb4099980e78244359ab9c6f056d6a7ec Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Date: Tue, 11 Aug 2020 22:59:38 +0200
Subject: [PATCH] media: rcar-csi2: Allocate v4l2_async_subdev dynamically
Git-commit: 2cac7cbfb4099980e78244359ab9c6f056d6a7ec
Patch-mainline: v5.10-rc1
References: git-fixes

v4l2_async_notifier_add_subdev() requires the asd to be allocated
dynamically, but the rcar-csi2 driver embeds it in the rcar_csi2
structure. This causes memory corruption when the notifier is destroyed
at remove time with v4l2_async_notifier_cleanup().

Fix this issue by registering the asd with
v4l2_async_notifier_add_fwnode_subdev(), which allocates it dynamically
internally.

Fixes: 769afd212b16 ("media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver driver")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/platform/rcar-vin/rcar-csi2.c |   24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

--- a/drivers/media/platform/rcar-vin/rcar-csi2.c
+++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
@@ -361,7 +361,6 @@ struct rcar_csi2 {
 	struct media_pad pads[NR_OF_RCAR_CSI2_PAD];
 
 	struct v4l2_async_notifier notifier;
-	struct v4l2_async_subdev asd;
 	struct v4l2_subdev *remote;
 
 	struct v4l2_mbus_framefmt mf;
@@ -810,6 +809,8 @@ static int rcsi2_parse_v4l2(struct rcar_
 
 static int rcsi2_parse_dt(struct rcar_csi2 *priv)
 {
+	struct v4l2_async_subdev *asd;
+	struct fwnode_handle *fwnode;
 	struct device_node *ep;
 	struct v4l2_fwnode_endpoint v4l2_ep = { .bus_type = 0 };
 	int ret;
@@ -833,24 +834,19 @@ static int rcsi2_parse_dt(struct rcar_cs
 		return ret;
 	}
 
-	priv->asd.match.fwnode =
-		fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
-	priv->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-
+	fwnode = fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
 	of_node_put(ep);
 
-	v4l2_async_notifier_init(&priv->notifier);
-
-	ret = v4l2_async_notifier_add_subdev(&priv->notifier, &priv->asd);
-	if (ret) {
-		fwnode_handle_put(priv->asd.match.fwnode);
-		return ret;
-	}
+	dev_dbg(priv->dev, "Found '%pOF'\n", to_of_node(fwnode));
 
+	v4l2_async_notifier_init(&priv->notifier);
 	priv->notifier.ops = &rcar_csi2_notify_ops;
 
-	dev_dbg(priv->dev, "Found '%pOF'\n",
-		to_of_node(priv->asd.match.fwnode));
+	asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier, fwnode,
+						    sizeof(*asd));
+	fwnode_handle_put(fwnode);
+	if (IS_ERR(asd))
+		return PTR_ERR(asd);
 
 	ret = v4l2_async_subdev_notifier_register(&priv->subdev,
 						  &priv->notifier);