[PATCH v1 03/11] ShellPkg: acpiview: FADT: Validate global pointer before use

["Krzysztof Koch" <krzysztof.koch@arm.com>]

Check if global pointers have been successfully updated before they
are used for further table parsing.

Signed-off-by: Krzysztof Koch <krzysztof.koch@arm.com>
---

Notes:
    v1:
    - Test against NULL pointers [Krzysztof]

 ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Fadt/FadtParser.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Fadt/FadtParser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Fadt/FadtParser.c
index e40c9ef8ee4b3285faf8c6edf3cb6236ee367397..e218e45926abced1096e75441e22108db7a3a811 100644
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Fadt/FadtParser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Fadt/FadtParser.c
@@ -203,6 +203,20 @@ ParseAcpiFadt (
     PARSER_PARAMS (FadtParser)
     );
 
+  // Check if the values used to control the parsing logic have been
+  // successfully read.
+  if ((DsdtAddress == NULL)       ||
+      (FadtMinorRevision == NULL) ||
+      (X_DsdtAddress == NULL)) {
+    IncrementErrorCount ();
+    Print (
+      L"ERROR: Insufficient table length. AcpiTableLength = %d. " \
+        L"FADT parsing aborted.\n",
+      AcpiTableLength
+      );
+    return;
+  }
+
   if (Trace) {
     Print (L"\nSummary:\n");
     PrintFieldName (2, L"FADT Version");
--
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'