ShellPkg: acpiview: Validate ACPI table 'Length' field

[mirror_edk2.git] / ShellPkg / Library / UefiShellAcpiViewCommandLib / AcpiTableParser.c

diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/AcpiTableParser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/AcpiTableParser.c
index d5500bcb2b4a55c7a69f45444aa49d36d2c1694f..501967c4dde680809c56e5d79ed744a1013a69e1 100644 (file)
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/AcpiTableParser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/AcpiTableParser.c
@@ -1,7 +1,7 @@
 /** @file\r
   ACPI table parser\r
 \r
-  Copyright (c) 2016 - 2019, ARM Limited. All rights reserved.\r
+  Copyright (c) 2016 - 2020, ARM Limited. All rights reserved.\r
   SPDX-License-Identifier: BSD-2-Clause-Patent\r
 **/\r
 \r
@@ -176,6 +176,7 @@ ProcessAcpiTable (
   CONST UINT32* AcpiTableSignature;\r
   CONST UINT32* AcpiTableLength;\r
   CONST UINT8*  AcpiTableRevision;\r
+  CONST UINT8*  SignaturePtr;\r
   PARSE_ACPI_TABLE_PROC ParserProc;\r
 \r
   ParseAcpiHeader (\r
@@ -193,6 +194,23 @@ ProcessAcpiTable (
 \r
   if (Trace) {\r
     DumpRaw (Ptr, *AcpiTableLength);\r
+\r
+    // Do not process the ACPI table any further if the table length read\r
+    // is invalid. The ACPI table should at least contain the table header.\r
+    if (*AcpiTableLength < sizeof (EFI_ACPI_DESCRIPTION_HEADER)) {\r
+      SignaturePtr = (CONST UINT8*)AcpiTableSignature;\r
+      IncrementErrorCount ();\r
+      Print (\r
+        L"ERROR: Invalid %c%c%c%c table length. Length = %d\n",\r
+        SignaturePtr[0],\r
+        SignaturePtr[1],\r
+        SignaturePtr[2],\r
+        SignaturePtr[3],\r
+        *AcpiTableLength\r
+        );\r
+      return;\r
+    }\r
+\r
     if (GetConsistencyChecking ()) {\r
       VerifyChecksum (TRUE, Ptr, *AcpiTableLength);\r
     }\r