[PATCH v1 06/11] ShellPkg: acpiview: SRAT: Validate global pointers before use

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

Check if SratRAType and SratRALength 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/Srat/SratParser.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Srat/SratParser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Srat/SratParser.c
index a8aa420487bb6bf29fc38221d0b221573c64b8b3..e09a7db8f5c92b44c96b6c37a44a39693352b442 100644
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Srat/SratParser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Srat/SratParser.c
@@ -219,6 +219,19 @@ ParseAcpiSrat (
       PARSER_PARAMS (SratResourceAllocationParser)
       );
 
+    // Check if the values used to control the parsing logic have been
+    // successfully read.
+    if ((SratRAType == NULL) ||
+        (SratRALength == NULL)) {
+      IncrementErrorCount ();
+      Print (
+        L"ERROR: Insufficient remaining table buffer length to read the " \
+          L"Static Resource Allocation structure header. Length = %d.\n",
+        AcpiTableLength - Offset
+        );
+      return;
+    }
+
     // Make sure the SRAT structure lies inside the table
     if ((Offset + *SratRALength) > AcpiTableLength) {
       IncrementErrorCount ();
--
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'