From 7c6075e2546dd818b7b87090a983429b1942796a Mon Sep 17 00:00:00 2001
From: Hao Wu <hao.a.wu@intel.com>
Date: Fri, 23 Dec 2016 13:04:38 +0800
Subject: [PATCH] MdeModulePkg/PrintLib: Add missing return status check for
 Print APIs

https://bugzilla.tianocore.org/show_bug.cgi?id=307

For the following APIs in PrintLib instance
MdeModulePkg\Library\DxePrintLibPrint2Protocol:
UnicodeVSPrint
UnicodeSPrint
UnicodeVSPrintAsciiFormat
UnicodeSPrintAsciiFormat
AsciiVSPrint
AsciiSPrint
AsciiVSPrintUnicodeFormat
AsciiSPrintUnicodeFormat

The internal function DxePrintLibPrint2ProtocolVaListToBaseList() will be
called to convert a VA_LIST to a BASE_LIST. However, those APIs miss
checking the return value of the internal function.

This commit adds codes to check the return value. If the VA_LIST fails to
be converted to a BASE_LIST, those PrintLib APIs will return 0 and leave
the output 'StartOfBuffer' unmodified.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
---
 .../DxePrintLibPrint2Protocol/PrintLib.c      | 94 +++++++++++--------
 1 file changed, 56 insertions(+), 38 deletions(-)

diff --git a/MdeModulePkg/Library/DxePrintLibPrint2Protocol/PrintLib.c b/MdeModulePkg/Library/DxePrintLibPrint2Protocol/PrintLib.c
index 4acdcb8714..01378687fd 100644
--- a/MdeModulePkg/Library/DxePrintLibPrint2Protocol/PrintLib.c
+++ b/MdeModulePkg/Library/DxePrintLibPrint2Protocol/PrintLib.c
@@ -6,7 +6,7 @@
   protocol related to this implementation, not in the public spec. So, this 
   library instance is only for this code base.
 
-Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2009 - 2017, 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
 which accompanies this distribution.  The full text of the license may be found at
@@ -71,7 +71,8 @@ PrintLibConstructor (
   @param  BaseListMarker  BASE_LIST style variable argument list consumed by processing Format.
   @param  Size            The size, in bytes, of the BaseListMarker buffer.
 
-  @return The number of bytes in BaseListMarker.  0 if BaseListMarker is too small.
+  @return TRUE   The VA_LIST has been converted to BASE_LIST.
+  @return FALSE  The VA_LIST has not been converted to BASE_LIST.
 
 **/
 BOOLEAN
@@ -205,6 +206,7 @@ DxePrintLibPrint2ProtocolVaListToBaseList (
     // If BASE_LIST is larger than Size, then return FALSE
     //
     if ((UINTN)((UINT8 *)BaseListMarker - (UINT8 *)BaseListStart) > Size) {
+      DEBUG ((DEBUG_ERROR, "The input variable argument list is too long. Please consider breaking into multiple print calls.\n"));
       return FALSE;
     }
 
@@ -264,15 +266,19 @@ UnicodeVSPrint (
   IN  VA_LIST       Marker
   )
 {
-  UINT64  BaseListMarker[256 / sizeof (UINT64)];
-
-  DxePrintLibPrint2ProtocolVaListToBaseList (
-    FALSE, 
-    (CHAR8 *)FormatString, 
-    Marker, 
-    (BASE_LIST)BaseListMarker, 
-    sizeof (BaseListMarker) - 8
-    );
+  UINT64   BaseListMarker[256 / sizeof (UINT64)];
+  BOOLEAN  Converted;
+
+  Converted = DxePrintLibPrint2ProtocolVaListToBaseList (
+                FALSE,
+                (CHAR8 *)FormatString,
+                Marker,
+                (BASE_LIST)BaseListMarker,
+                sizeof (BaseListMarker) - 8
+                );
+  if (!Converted) {
+    return 0;
+  }
 
   return UnicodeBSPrint (StartOfBuffer, BufferSize, FormatString, (BASE_LIST)BaseListMarker);
 }
@@ -417,15 +423,19 @@ UnicodeVSPrintAsciiFormat (
   IN  VA_LIST      Marker
   )
 {
-  UINT64  BaseListMarker[256 / sizeof (UINT64)];
-
-  DxePrintLibPrint2ProtocolVaListToBaseList (
-    TRUE, 
-    FormatString, 
-    Marker, 
-    (BASE_LIST)BaseListMarker, 
-    sizeof (BaseListMarker) - 8
-    );
+  UINT64   BaseListMarker[256 / sizeof (UINT64)];
+  BOOLEAN  Converted;
+
+  Converted = DxePrintLibPrint2ProtocolVaListToBaseList (
+                TRUE,
+                FormatString,
+                Marker,
+                (BASE_LIST)BaseListMarker,
+                sizeof (BaseListMarker) - 8
+                );
+  if (!Converted) {
+    return 0;
+  }
 
   return UnicodeBSPrintAsciiFormat (StartOfBuffer, BufferSize, FormatString, (BASE_LIST)BaseListMarker);
 }
@@ -621,15 +631,19 @@ AsciiVSPrint (
   IN  VA_LIST       Marker
   )
 {
-  UINT64  BaseListMarker[256 / sizeof (UINT64)];
-
-  DxePrintLibPrint2ProtocolVaListToBaseList (
-    TRUE, 
-    FormatString, 
-    Marker, 
-    (BASE_LIST)BaseListMarker, 
-    sizeof (BaseListMarker) - 8
-    );
+  UINT64   BaseListMarker[256 / sizeof (UINT64)];
+  BOOLEAN  Converted;
+
+  Converted = DxePrintLibPrint2ProtocolVaListToBaseList (
+                TRUE,
+                FormatString,
+                Marker,
+                (BASE_LIST)BaseListMarker,
+                sizeof (BaseListMarker) - 8
+                );
+  if (!Converted) {
+    return 0;
+  }
 
   return AsciiBSPrint (StartOfBuffer, BufferSize, FormatString, (BASE_LIST)BaseListMarker);
 }
@@ -771,15 +785,19 @@ AsciiVSPrintUnicodeFormat (
   IN  VA_LIST       Marker
   )
 {
-  UINT64  BaseListMarker[256 / sizeof (UINT64)];
-
-  DxePrintLibPrint2ProtocolVaListToBaseList (
-    FALSE, 
-    (CHAR8 *)FormatString, 
-    Marker, 
-    (BASE_LIST)BaseListMarker, 
-    sizeof (BaseListMarker) - 8
-    );
+  UINT64   BaseListMarker[256 / sizeof (UINT64)];
+  BOOLEAN  Converted;
+
+  Converted = DxePrintLibPrint2ProtocolVaListToBaseList (
+                FALSE,
+                (CHAR8 *)FormatString,
+                Marker,
+                (BASE_LIST)BaseListMarker,
+                sizeof (BaseListMarker) - 8
+                );
+  if (!Converted) {
+    return 0;
+  }
 
   return AsciiBSPrintUnicodeFormat (StartOfBuffer, BufferSize, FormatString, (BASE_LIST)BaseListMarker);
 }
-- 
2.39.2