From: Krzysztof Koch <krzysztof.koch@arm.com>
Date: Mon, 20 Jan 2020 11:13:47 +0000 (+0800)
Subject: ShellPkg: acpiview: MADT: Validate global pointers before use
X-Git-Tag: edk2-stable202002~57
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=c4a53853c10bee5be821cf0df2d1514d0cff7dc9

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 90bdafea19..438905cb24 100644
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Madt/MadtParser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Madt/MadtParser.c
@@ -260,6 +260,19 @@ ParseAcpiMadt (
       PARSER_PARAMS (MadtInterruptControllerHeaderParser)
       );
 
+    // Check if the values used to control the parsing logic have been
+    // successfully read.
+    if ((MadtInterruptControllerType == NULL) ||
+        (MadtInterruptControllerLength == NULL)) {
+      IncrementErrorCount ();
+      Print (
+        L"ERROR: Insufficient remaining table buffer length to read the " \
+          L"Interrupt Controller Structure header. Length = %d.\n",
+        AcpiTableLength - Offset
+        );
+      return;
+    }
+
     // Make sure forward progress is made.
     if (*MadtInterruptControllerLength < 2) {
       IncrementErrorCount ();