ShellPkg: acpiview: DBG2: Validate global pointers before use

Check if global (in the scope of the DBG2 parser) pointers have been
successfully updated before they are used for further table parsing.

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

1 files changed, 43 insertions, 0 deletions

diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Dbg2/Dbg2Parser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Dbg2/Dbg2Parser.c
index 869e700b9b..0f730a306a 100644
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Dbg2/Dbg2Parser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Dbg2/Dbg2Parser.c
@@ -123,6 +123,24 @@ DumpDbgDeviceInfo (
     PARSER_PARAMS (DbgDevInfoParser)

     );

 

+  // Check if the values used to control the parsing logic have been

+  // successfully read.

+  if ((GasCount == NULL)              ||

+      (NameSpaceStringLength == NULL) ||

+      (NameSpaceStringOffset == NULL) ||

+      (OEMDataLength == NULL)         ||

+      (OEMDataOffset == NULL)         ||

+      (BaseAddrRegOffset == NULL)     ||

+      (AddrSizeOffset == NULL)) {

+    IncrementErrorCount ();

+    Print (

+      L"ERROR: Insufficient Debug Device Information Structure length. " \

+        L"Length = %d.\n",

+      Length

+      );

+    return;

+  }

+

   // GAS

   Index = 0;

   Offset = *BaseAddrRegOffset;

@@ -224,6 +242,18 @@ ParseAcpiDbg2 (
              PARSER_PARAMS (Dbg2Parser)

              );

 

+  // Check if the values used to control the parsing logic have been

+  // successfully read.

+  if ((OffsetDbgDeviceInfo == NULL) ||

+      (NumberDbgDeviceInfo == NULL)) {

+    IncrementErrorCount ();

+    Print (

+      L"ERROR: Insufficient table length. AcpiTableLength = %d\n",

+      AcpiTableLength

+      );

+    return;

+  }

+

   Offset = *OffsetDbgDeviceInfo;

   Index = 0;

 

@@ -239,6 +269,19 @@ ParseAcpiDbg2 (
       PARSER_PARAMS (DbgDevInfoHeaderParser)

       );

 

+    // Check if the values used to control the parsing logic have been

+    // successfully read.

+    if (DbgDevInfoLen == NULL) {

+      IncrementErrorCount ();

+      Print (

+        L"ERROR: Insufficient remaining table buffer length to read the " \

+          L"Debug Device Information structure's 'Length' field. " \

+          L"RemainingTableBufferLength = %d.\n",

+        AcpiTableLength - Offset

+        );

+      return;

+    }

+

     // Make sure the Debug Device Information structure lies inside the table.

     if ((Offset + *DbgDevInfoLen) > AcpiTableLength) {

       IncrementErrorCount ();