diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 732e6ed5d7b4..eaaf94e33533 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -2073,11 +2073,17 @@ static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
 
 		if (len < sizeof(*d) ||
 		    d->bFirstInterfaceNumber >= ffs->interfaces_count ||
-		    d->Reserved1)
+		    d->Reserved1 != 1) {
+			pr_err("%s(): Invalid os_desct_ext_compat\n",
+							__func__);
 			return -EINVAL;
+		}
 		for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
-			if (d->Reserved2[i])
+			if (d->Reserved2[i]) {
+				pr_err("%s(): Invalid Reserved2 of ext_compat\n",
+							__func__);
 				return -EINVAL;
+			}
 
 		length = sizeof(struct usb_ext_compat_desc);
 	}