Add comment for modules which have external input.

signed-off-by: jiewen.yao@intel.com
reviewed-by: guo.dong@intel.com
reviewed-by: ting.ye@intel.com
reviewed-by: liming.gao@intel.com
reviewed-by: elvin.li@intel.com



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13446 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 34 insertions, 0 deletions

diff --git a/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c b/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
index 49358de013..fe7d5b9352 100644
--- a/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
+++ b/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
@@ -2,6 +2,20 @@
   The common variable operation routines shared by DXE_RUNTIME variable

   module and DXE_SMM variable module.

 

+  Caution: This module requires additional review when modified.

+  This driver will have external input - variable data. They may be input in SMM mode.

+  This external input must be validated carefully to avoid security issue like

+  buffer overflow, integer overflow.

+

+  VariableServiceGetNextVariableName () and VariableServiceQueryVariableInfo() are external API.

+  They need check input parameter.

+

+  VariableServiceGetVariable() and VariableServiceSetVariable() are external API

+  to receive datasize and data buffer. The size should be checked carefully.

+

+  VariableServiceSetVariable() should also check authenticate data to avoid buffer overflow,

+  integer overflow. It should also check attribute to avoid authentication bypass.

+

 Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.<BR>

 This program and the accompanying materials

 are licensed and made available under the terms and conditions of the BSD License

@@ -1945,6 +1959,10 @@ IsHwErrRecVariable (
 

   This code finds variable in storage blocks (Volatile or Non-Volatile).

 

+  Caution: This function may receive untrusted input.

+  This function may be invoked in SMM mode, and datasize is external input.

+  This function will do basic validation, before parse the data.

+

   @param VariableName               Name of Variable to be found.

   @param VendorGuid                 Variable vendor GUID.

   @param Attributes                 Attribute value of the variable found.

@@ -2022,6 +2040,9 @@ Done:
 

   This code Finds the Next available variable.

 

+  Caution: This function may receive untrusted input.

+  This function may be invoked in SMM mode. This function will do basic validation, before parse the data.

+

   @param VariableNameSize           Size of the variable name.

   @param VariableName               Pointer to variable name.

   @param VendorGuid                 Variable Vendor Guid.

@@ -2167,6 +2188,13 @@ Done:
 

   This code sets variable in storage blocks (Volatile or Non-Volatile).

 

+  Caution: This function may receive untrusted input.

+  This function may be invoked in SMM mode, and datasize and data are external input.

+  This function will do basic validation, before parse the data.

+  This function will parse the authentication carefully to avoid security issues, like

+  buffer overflow, integer overflow.

+  This function will check attribute carefully to avoid authentication bypass.

+

   @param VariableName                     Name of Variable to be found.

   @param VendorGuid                       Variable vendor GUID.

   @param Attributes                       Attribute value of the variable found

@@ -2336,6 +2364,9 @@ VariableServiceSetVariable (
 

   This code returns information about the EFI variables.

 

+  Caution: This function may receive untrusted input.

+  This function may be invoked in SMM mode. This function will do basic validation, before parse the data.

+

   @param Attributes                     Attributes bitmask to specify the type of variables

                                         on which to return information.

   @param MaximumVariableStorageSize     Pointer to the maximum size of the storage space available

@@ -2497,6 +2528,9 @@ VariableServiceQueryVariableInfo (
 /**

   This function reclaims variable storage if free size is below the threshold.

 

+  Caution: This function may be invoked at SMM runtime.

+  Care must be taken to make sure not security issue at runtime.

+

 **/

 VOID

 ReclaimForOS(