drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted

platform_device_register_data() can fail and return an ERR_PTR, but the
return value is used without checking, leading to an invalid pointer
being stored in ddp_comp[].dev and passed to component_match_add() and
mtk_ddp_comp_init(), which could result in a kernel crash.

Add an IS_ERR() check to jump to the error handling path on failure.

Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Cc: stable@vger.kernel.org
Signed-off-by: Haojie Li <lihaojie@kylinos.cn>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

1 files changed, 88 insertions, 0 deletions

diff --git a/drivers/usb/serial/wishbone-serial.c b/drivers/usb/serial/wishbone-serial.c
new file mode 100644
index 000000000..4a1fed4cb
--- /dev/null
+++ b/drivers/usb/serial/wishbone-serial.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * USB Wishbone-Serial adapter driver
+ *
+ * Copyright (C) 2013 Wesley W. Terpstra <w.terpstra@gsi.de>
+ * Copyright (C) 2013 GSI Helmholtz Centre for Heavy Ion Research GmbH
+ */
+
+#include <linux/kernel.h>
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+
+#define GSI_VENDOR_OPENCLOSE 0xB0
+
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE_AND_INTERFACE_INFO(0x1D50, 0x6062, 0xFF, 0xFF, 0xFF) },
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+/*
+ * Etherbone must be told that a new stream has begun before data arrives.
+ * This is necessary to restart the negotiation of Wishbone bus parameters.
+ * Similarly, when the stream ends, Etherbone must be told so that the cycle
+ * line can be driven low in the case that userspace failed to do so.
+ */
+static int usb_gsi_openclose(struct usb_serial_port *port, int value)
+{
+	struct usb_device *dev = port->serial->dev;
+
+	return usb_control_msg(
+		dev,
+		usb_sndctrlpipe(dev, 0), /* Send to EP0OUT */
+		GSI_VENDOR_OPENCLOSE,
+		USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+		value, /* wValue = device is open(1) or closed(0) */
+		port->serial->interface->cur_altsetting->desc.bInterfaceNumber,
+		NULL, 0,  /* There is no data stage */
+		5000); /* Timeout till operation fails */
+}
+
+static int wishbone_serial_open(struct tty_struct *tty,
+				struct usb_serial_port *port)
+{
+	int retval;
+
+	retval = usb_gsi_openclose(port, 1);
+	if (retval) {
+		dev_err(&port->serial->dev->dev,
+		       "Could not mark device as open (%d)\n",
+		       retval);
+		return retval;
+	}
+
+	retval = usb_serial_generic_open(tty, port);
+	if (retval)
+		usb_gsi_openclose(port, 0);
+
+	return retval;
+}
+
+static void wishbone_serial_close(struct usb_serial_port *port)
+{
+	usb_serial_generic_close(port);
+	usb_gsi_openclose(port, 0);
+}
+
+static struct usb_serial_driver wishbone_serial_device = {
+	.driver = {
+		.name =		"wishbone_serial",
+	},
+	.id_table =		id_table,
+	.num_ports =		1,
+	.open =			&wishbone_serial_open,
+	.close =		&wishbone_serial_close,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&wishbone_serial_device, NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+MODULE_AUTHOR("Wesley W. Terpstra <w.terpstra@gsi.de>");
+MODULE_DESCRIPTION("USB Wishbone-Serial adapter");
+MODULE_LICENSE("GPL");