From f8e6bcb6e7c350eb7be887dfdb5aad43cd6373af Mon Sep 17 00:00:00 2001
From: Bret Barkelew <bret@corthon.com>
Date: Sat, 10 Apr 2021 02:25:11 +0800
Subject: [PATCH] MdeModulePkg: Initialize temp variable in VarCheckPolicyLib

DumpVariablePolicy() will return EFI_INVALID_PARAMETER if the Buffer
pointer is NULL and the indirect Size is anything but 0. Since this
TempSize was not being initialized it is very likely that this sequence
would not return the total buffer size as expected.

Bugzilla: https://bugzilla.tianocore.org/show_bug.cgi?id=3310

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Bret Barkelew <bret.barkelew@microsoft.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
---
 MdeModulePkg/Library/VarCheckPolicyLib/VarCheckPolicyLib.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MdeModulePkg/Library/VarCheckPolicyLib/VarCheckPolicyLib.c b/MdeModulePkg/Library/VarCheckPolicyLib/VarCheckPolicyLib.c
index 14e1904e96..e50edb4ffc 100644
--- a/MdeModulePkg/Library/VarCheckPolicyLib/VarCheckPolicyLib.c
+++ b/MdeModulePkg/Library/VarCheckPolicyLib/VarCheckPolicyLib.c
@@ -216,6 +216,7 @@ VarCheckPolicyLibMmiHandler (
         DumpParamsOut->TotalSize = 0;
         DumpParamsOut->PageSize = 0;
         DumpParamsOut->HasMore = FALSE;
+        TempSize = 0;
         SubCommandStatus = DumpVariablePolicy (NULL, &TempSize);
         if (SubCommandStatus == EFI_BUFFER_TOO_SMALL && TempSize > 0) {
           mCurrentPaginationCommand = VAR_CHECK_POLICY_COMMAND_DUMP;
-- 
2.39.2