[PATCH] platform/x86: wmi: Add Null check for device

[Chenyuan Yang]

Not all devices have an ACPI companion fwnode, so device might be NULL.
This is similar to the commit cd2fd6eab480
("platform/x86: int3472: Check for adev == NULL").

Add a check for device not being set and return -ENODEV in that case to
avoid a possible NULL pointer deref in parse_wdg().

Note, acpi_wmi_probe() under the same file has such a check.

Signed-off-by: Chenyuan Yang <chenyuan0y@xxxxxxxxx>
---
 drivers/platform/x86/wmi.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 646370bd6b03..54e697838c1e 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -1091,6 +1091,9 @@ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
 	u32 i, total;
 	int retval;
 
+	if (!device)
+		return -ENODEV;
+
 	status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
 	if (ACPI_FAILURE(status))
 		return -ENXIO;
-- 
2.34.1