From 2cb874352423fcfd180199e6de8298567dff8e7f Mon Sep 17 00:00:00 2001
From: Hao Wu <hao.a.wu@intel.com>
Date: Tue, 11 Oct 2016 10:13:26 +0800
Subject: [PATCH] BaseTools/GenFfs: Avoid possible NULL pointer dereference

Cc: Liming Gao <liming.gao@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
---
 BaseTools/Source/C/GenFfs/GenFfs.c | 36 ++++++++++++++++--------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/BaseTools/Source/C/GenFfs/GenFfs.c b/BaseTools/Source/C/GenFfs/GenFfs.c
index 9a738cbb6a..78e5097fb4 100644
--- a/BaseTools/Source/C/GenFfs/GenFfs.c
+++ b/BaseTools/Source/C/GenFfs/GenFfs.c
@@ -1,7 +1,7 @@
 /** @file
 This file contains functions required to generate a Firmware File System file.
 
-Copyright (c) 2004 - 2014, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2004 - 2016, 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        
@@ -842,7 +842,7 @@ Returns:
                );
   }
 
-  if (EFI_ERROR (Status)) {
+  if (EFI_ERROR (Status) || (FileBuffer == NULL)) {
     goto Finish;
   }
   
@@ -915,22 +915,24 @@ Returns:
   //
   // Open output file to write ffs data.
   //
-  remove(OutputFileName);
-  FfsFile = fopen (LongFilePath (OutputFileName), "wb");
-  if (FfsFile == NULL) {
-    Error (NULL, 0, 0001, "Error opening file", OutputFileName);
-    goto Finish;
-  }
-  //
-  // write header
-  //
-  fwrite (&FfsFileHeader, 1, HeaderSize, FfsFile);
-  //
-  // write data
-  //
-  fwrite (FileBuffer, 1, FileSize - HeaderSize, FfsFile);
+  if (OutputFileName != NULL) {
+    remove(OutputFileName);
+    FfsFile = fopen (LongFilePath (OutputFileName), "wb");
+    if (FfsFile == NULL) {
+      Error (NULL, 0, 0001, "Error opening file", OutputFileName);
+      goto Finish;
+    }
+    //
+    // write header
+    //
+    fwrite (&FfsFileHeader, 1, HeaderSize, FfsFile);
+    //
+    // write data
+    //
+    fwrite (FileBuffer, 1, FileSize - HeaderSize, FfsFile);
 
-  fclose (FfsFile);
+    fclose (FfsFile);
+  }
 
 Finish:
   if (InputFileName != NULL) {