diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 737e3c19967bee3e81f57cc041ec9989ec38fb57..71dc5d768fa5cef3edc5ac27c84c032d2a0a0dcf 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -742,6 +742,22 @@ static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype,
 		if ((index & ~USB_DIR_IN) == 0)
 			return 0;
 		ret = findintfep(ps->dev, index);
+		if (ret < 0) {
+			/*
+			 * Some not fully compliant Win apps seem to get
+			 * index wrong and have the endpoint number here
+			 * rather than the endpoint address (with the
+			 * correct direction). Win does let this through,
+			 * so we'll not reject it here but leave it to
+			 * the device to not break KVM. But we warn.
+			 */
+			ret = findintfep(ps->dev, index ^ 0x80);
+			if (ret >= 0)
+				dev_info(&ps->dev->dev,
+					"%s: process %i (%s) requesting ep %02x but needs %02x\n",
+					__func__, task_pid_nr(current),
+					current->comm, index, index ^ 0x80);
+		}
 		if (ret >= 0)
 			ret = checkintf(ps, ret);
 		break;