ShellPkg: acpiview: MADT: Validate global pointers before use

Check if the MadtInterruptControllerType and
MadtInterruptControllerLength pointers have been successfully updated
before they are used for further table parsing.

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

diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Madt/MadtParser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Madt/MadtParser.c
index 90bdafea1970db522e8ed96de7c6e986cdaca5ba..438905cb24f58b8b82e8fe61280e72f765d578d8 100644 (file)
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Madt/MadtParser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Madt/MadtParser.c
@@ -260,6 +260,19 @@ ParseAcpiMadt (
       PARSER_PARAMS (MadtInterruptControllerHeaderParser)\r
       );\r
 \r
+    // Check if the values used to control the parsing logic have been\r
+    // successfully read.\r
+    if ((MadtInterruptControllerType == NULL) ||\r
+        (MadtInterruptControllerLength == NULL)) {\r
+      IncrementErrorCount ();\r
+      Print (\r
+        L"ERROR: Insufficient remaining table buffer length to read the " \\r
+          L"Interrupt Controller Structure header. Length = %d.\n",\r
+        AcpiTableLength - Offset\r
+        );\r
+      return;\r
+    }\r
+\r
     // Make sure forward progress is made.\r
     if (*MadtInterruptControllerLength < 2) {\r
       IncrementErrorCount ();\r