diff --git a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c
index 58cb5d8b1f..f0d3472ea5 100644
--- a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c
+++ b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c
@@ -52,6 +52,10 @@ GetBarResource (
 
   BarIndex -= (UINT8)Dev->BarOffset;
 
+  if (BarIndex >= Dev->BarCount) {
+    return EFI_UNSUPPORTED;
+  }
+
   for (Desc = Dev->Device->Resources;
        Desc->Desc != ACPI_END_TAG_DESCRIPTOR;
        Desc = (VOID *)((UINT8 *)Desc + Desc->Len + 3)) {
@@ -597,6 +601,19 @@ CoherentPciIoMap (
   EFI_STATUS                            Status;
   NON_DISCOVERABLE_PCI_DEVICE_MAP_INFO  *MapInfo;
 
+  if (Operation != EfiPciIoOperationBusMasterRead &&
+      Operation != EfiPciIoOperationBusMasterWrite &&
+      Operation != EfiPciIoOperationBusMasterCommonBuffer) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (HostAddress   == NULL ||
+      NumberOfBytes == NULL ||
+      DeviceAddress == NULL ||
+      Mapping       == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   //
   // If HostAddress exceeds 4 GB, and this device does not support 64-bit DMA
   // addressing, we need to allocate a bounce buffer and copy over the data.
@@ -720,6 +737,11 @@ CoherentPciIoAllocateBuffer (
     return EFI_UNSUPPORTED;
   }
 
+  if ((MemoryType != EfiBootServicesData) &&
+      (MemoryType != EfiRuntimeServicesData)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   //
   // Allocate below 4 GB if the dual address cycle attribute has not
   // been set. If the system has no memory available below 4 GB, there
@@ -877,6 +899,10 @@ NonCoherentPciIoAllocateBuffer (
   NON_DISCOVERABLE_DEVICE_UNCACHED_ALLOCATION *Alloc;
   VOID                                        *AllocAddress;
 
+  if (HostAddress == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
 
   Status = CoherentPciIoAllocateBuffer (This, Type, MemoryType, Pages,
@@ -995,6 +1021,19 @@ NonCoherentPciIoMap (
   EFI_GCD_MEMORY_SPACE_DESCRIPTOR       GcdDescriptor;
   BOOLEAN                               Bounce;
 
+  if (HostAddress   == NULL ||
+      NumberOfBytes == NULL ||
+      DeviceAddress == NULL ||
+      Mapping       == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (Operation != EfiPciIoOperationBusMasterRead &&
+      Operation != EfiPciIoOperationBusMasterWrite &&
+      Operation != EfiPciIoOperationBusMasterCommonBuffer) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   MapInfo = AllocatePool (sizeof *MapInfo);
   if (MapInfo == NULL) {
     return EFI_OUT_OF_RESOURCES;
@@ -1232,8 +1271,17 @@ PciIoAttributes (
   NON_DISCOVERABLE_PCI_DEVICE   *Dev;
   BOOLEAN                       Enable;
 
+  #define DEV_SUPPORTED_ATTRIBUTES \
+    (EFI_PCI_DEVICE_ENABLE | EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE)
+
   Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
 
+  if (Attributes) {
+      if ((Attributes & (~(DEV_SUPPORTED_ATTRIBUTES))) != 0) {
+        return EFI_UNSUPPORTED;
+      }
+    }
+
   Enable = FALSE;
   switch (Operation) {
   case EfiPciIoAttributeOperationGet:
@@ -1247,7 +1295,7 @@ PciIoAttributes (
     if (Result == NULL) {
       return EFI_INVALID_PARAMETER;
     }
-    *Result = EFI_PCI_DEVICE_ENABLE | EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE;
+    *Result = DEV_SUPPORTED_ATTRIBUTES;
     break;
 
   case EfiPciIoAttributeOperationEnable: