From 3e8670718dc8d10266a5bedfad2bc1de1ec3149a Mon Sep 17 00:00:00 2001
From: ydong10 <ydong10@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Fri, 25 May 2012 05:04:13 +0000
Subject: Refine logic about validate boot option.

Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13362 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../Library/GenericBdsLib/BdsMisc.c                | 54 ++++++----------------
 1 file changed, 13 insertions(+), 41 deletions(-)

(limited to 'IntelFrameworkModulePkg')

diff --git a/IntelFrameworkModulePkg/Library/GenericBdsLib/BdsMisc.c b/IntelFrameworkModulePkg/Library/GenericBdsLib/BdsMisc.c
index ada77d2..0a034cd 100644
--- a/IntelFrameworkModulePkg/Library/GenericBdsLib/BdsMisc.c
+++ b/IntelFrameworkModulePkg/Library/GenericBdsLib/BdsMisc.c
@@ -455,7 +455,7 @@ GetDevicePathSizeEx (
   bigger than MaxStringLen, return length 0 to indicate that this is an 
   invalidate string.
 
-  This function returns the number of Unicode characters in the Null-terminated
+  This function returns the byte length of Unicode characters in the Null-terminated
   Unicode string specified by String. 
 
   If String is NULL, then ASSERT().
@@ -479,13 +479,13 @@ StrSizeEx (
   ASSERT (String != NULL && MaxStringLen != 0);
   ASSERT (((UINTN) String & BIT0) == 0);
 
-  for (Length = 0; *String != L'\0' && MaxStringLen != Length; String++, Length++);
+  for (Length = 0; *String != L'\0' && MaxStringLen != Length; String++, Length+=2);
 
   if (*String != L'\0' && MaxStringLen == Length) {
     return 0;
   }
 
-  return (Length + 1) * sizeof (*String);
+  return Length + 2;
 }
 
 /**
@@ -507,9 +507,12 @@ ValidateOption (
   UINT16                    FilePathSize;
   UINT8                     *TempPtr;
   EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
-  EFI_DEVICE_PATH_PROTOCOL  *TempPath;
   UINTN                     TempSize;
 
+  if (VariableSize <= sizeof (UINT16) + sizeof (UINT32)) {
+    return FALSE;
+  }
+
   //
   // Skip the option attribute
   //
@@ -525,14 +528,14 @@ ValidateOption (
   //
   // Get the option's description string size
   //
-  TempSize = StrSizeEx ((CHAR16 *) TempPtr, VariableSize);
+  TempSize = StrSizeEx ((CHAR16 *) TempPtr, VariableSize - sizeof (UINT16) - sizeof (UINT32));
   TempPtr += TempSize;
 
   //
   // Get the option's device path
   //
   DevicePath =  (EFI_DEVICE_PATH_PROTOCOL *) TempPtr;
-  TempPtr    += FilePathSize;
+  TempPtr   += FilePathSize;
 
   //
   // Validation boot option variable.
@@ -541,21 +544,11 @@ ValidateOption (
     return FALSE;
   }
 
-  if (TempSize + FilePathSize + sizeof (UINT16) + sizeof (UINT16) > VariableSize) {
+  if (TempSize + FilePathSize + sizeof (UINT16) + sizeof (UINT32) > VariableSize) {
     return FALSE;
   }
 
-  TempPath = DevicePath;
-  while (FilePathSize > 0) {
-    TempSize = GetDevicePathSizeEx (TempPath, FilePathSize);
-    if (TempSize == 0) {
-      return FALSE;
-    }
-    FilePathSize = (UINT16) (FilePathSize - TempSize);
-    TempPath    += TempSize;
-  }
-
-  return TRUE;
+  return GetDevicePathSizeEx (DevicePath, FilePathSize) != 0;
 }
 
 /**
@@ -608,13 +601,12 @@ BdsLibVariableToOption (
   UINT8                     *TempPtr;
   UINTN                     VariableSize;
   EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
-  EFI_DEVICE_PATH_PROTOCOL  *TempPath;
   BDS_COMMON_OPTION         *Option;
   VOID                      *LoadOptions;
   UINT32                    LoadOptionsSize;
   CHAR16                    *Description;
   UINT8                     NumOff;
-  UINTN                     TempSize;
+
   //
   // Read the variable. We will never free this data.
   //
@@ -659,11 +651,7 @@ BdsLibVariableToOption (
   //
   // Get the option's description string size
   //
-  TempSize = StrSizeEx ((CHAR16 *) TempPtr, VariableSize);
-  if (TempSize == 0) {
-    return NULL;
-  }
-  TempPtr += TempSize;
+  TempPtr += StrSize((CHAR16 *) TempPtr);
 
   //
   // Get the option's device path
@@ -672,25 +660,9 @@ BdsLibVariableToOption (
   TempPtr    += FilePathSize;
 
   //
-  // Validation device path.
-  //
-  TempPath       = DevicePath;
-  while (FilePathSize > 0) {
-    TempSize = GetDevicePathSizeEx (TempPath, FilePathSize);
-    if (TempSize == 0) {
-      return NULL;
-    }
-    FilePathSize = (UINT16) (FilePathSize - TempSize);
-    TempPath    += TempSize;
-  }
-
-  //
   // Get load opion data.
   //
   LoadOptions     = TempPtr;
-  if (VariableSize < (UINTN)(TempPtr - Variable)) {
-    return NULL;
-  }
   LoadOptionsSize = (UINT32) (VariableSize - (UINTN) (TempPtr - Variable));
 
   //
-- 
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