diff --git a/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBoot.c b/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBoot.c
index 0b35cbacf0..c35c7bdc12 100644
--- a/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBoot.c
+++ b/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBoot.c
@@ -736,6 +736,13 @@ UsbBootDetectMedia (
     return Status;
   }
 
+  //
+  // Simply reject device whose block size is unacceptable small (==0) or large (>64K).
+  //
+  if ((Media->BlockSize == 0) || (Media->BlockSize > USB_BOOT_MAX_CARRY_SIZE)) {
+    return EFI_DEVICE_ERROR;
+  }
+
   //
   // Detect whether it is necessary to reinstall the Block I/O Protocol.
   //