HID: multitouch: Add NULL check in mt_input_configured

devm_kasprintf() can return a NULL pointer on failure,but this
returned value in mt_input_configured() is not checked.
Add NULL check in mt_input_configured(), to handle kernel NULL
pointer dereference error.

Fixes: 4794394 ("HID: multitouch: Correct devm device reference for hidinput input_dev name")
Signed-off-by: Charles Han <hanchunchao@inspur.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

Author: Charles Han

drivers/hid/hid-multitouch.c

@@ -1679,9 +1679,12 @@ static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
 		break;
 	}
 
-	if (suffix)
+	if (suffix) {
 		hi->input->name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
 						 "%s %s", hdev->name, suffix);
+		if (!hi->input->name)
+			return -ENOMEM;
+	}
 
 	return 0;
 }