IntelSiliconPkg IntelVTdDxe: Fix potential NULL pointer dereference

[mirror_edk2.git] / IntelSiliconPkg / Feature / VTd / IntelVTdDxe / DmarAcpiTable.c

diff --git a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c
index ce350bafbe3ffdee176909d46a7626d9833e779c..342830a01fb05135706b610c8225fac98ab5eb78 100644 (file)
--- a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c
+++ b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c
@@ -1,6 +1,6 @@
 /** @file\r
 \r
-  Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.<BR>\r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
   which accompanies this distribution.  The full text of the license may be found at\r
@@ -27,7 +27,7 @@ typedef struct {
 \r
 #pragma pack()\r
 \r
-EFI_ACPI_DMAR_HEADER  *mAcpiDmarTable;\r
+EFI_ACPI_DMAR_HEADER  *mAcpiDmarTable = NULL;\r
 \r
 /**\r
   Dump DMAR DeviceScopeEntry.\r
@@ -889,7 +889,7 @@ ScanTableInRSDT (
   EntryPtr = &Rsdt->Entry;\r
   for (Index = 0; Index < EntryCount; Index ++, EntryPtr ++) {\r
     Table = (EFI_ACPI_DESCRIPTION_HEADER*)((UINTN)(*EntryPtr));\r
-    if (Table->Signature == Signature) {\r
+    if ((Table != NULL) && (Table->Signature == Signature)) {\r
       return Table;\r
     }\r
   }\r
@@ -923,7 +923,7 @@ ScanTableInXSDT (
   for (Index = 0; Index < EntryCount; Index ++) {\r
     CopyMem (&EntryPtr, (VOID *)(BasePtr + Index * sizeof(UINT64)), sizeof(UINT64));\r
     Table = (EFI_ACPI_DESCRIPTION_HEADER*)((UINTN)(EntryPtr));\r
-    if (Table->Signature == Signature) {\r
+    if ((Table != NULL) && (Table->Signature == Signature)) {\r
       return Table;\r
     }\r
   }\r
@@ -1005,6 +1005,9 @@ GetDmarAcpiTable (
                &AcpiTable\r
                );\r
   }\r
+  if (EFI_ERROR (Status)) {\r
+    return EFI_NOT_FOUND;\r
+  }\r
   ASSERT (AcpiTable != NULL);\r
 \r
   mAcpiDmarTable = FindAcpiPtr (\r