[PATCH] usb: typec: ucsi: acpi: Check ACPI companion before use

[Jiale Yao <yaojiale02@163.com>]

Platform drivers can be forced to bind to devices outside their match
tables through driver_override. ucsi_acpi_probe() assumes that every bound
device has an ACPI companion and accesses adev->dep_unmet without checking.

Return -ENODEV when the companion is absent to avoid a NULL pointer
dereference.

Signed-off-by: Jiale Yao <yaojiale02@163.com>
---
 drivers/usb/typec/ucsi/ucsi_acpi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c
index 5697ccc24ec3..e8e3205cab9b 100644
--- a/drivers/usb/typec/ucsi/ucsi_acpi.c
+++ b/drivers/usb/typec/ucsi/ucsi_acpi.c
@@ -222,14 +222,18 @@ static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
 
 static int ucsi_acpi_probe(struct platform_device *pdev)
 {
-	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
 	const struct ucsi_operations *ops = &ucsi_acpi_ops;
 	const struct dmi_system_id *id;
+	struct acpi_device *adev;
 	struct ucsi_acpi *ua;
 	struct resource *res;
 	acpi_status status;
 	int ret;
 
+	adev = ACPI_COMPANION(&pdev->dev);
+	if (!adev)
+		return -ENODEV;
+
 	if (adev->dep_unmet)
 		return -EPROBE_DEFER;
 
-- 
2.34.1