[PATCH] ShellPkg/UefiShellLevel2CommansLib: Pointer Resonse should be checked

["Gao, Zhichao" <zhichao.gao@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2049

ShellPkg\Library\UefiShellLevel2CommandsLib\Cp.c line 104 and
ShellPkg\Library\UefiShellLevel2CommandsLib\Mv.c line 640, the
pointer variable Response may be a NULL pointer. So we should
make sure that it isn't NULL before dereference it.

If Response is NULL that indicates a EFI_OUT_OF_RESOURCES
error, directly return SHELL_ABORTED.

Cc: Jaben Carsey <jaben.carsey@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
---
 ShellPkg/Library/UefiShellLevel2CommandsLib/Cp.c | 5 ++++-
 ShellPkg/Library/UefiShellLevel2CommandsLib/Mv.c | 5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/ShellPkg/Library/UefiShellLevel2CommandsLib/Cp.c b/ShellPkg/Library/UefiShellLevel2CommandsLib/Cp.c
index 18b05b5803..4a2c2cfe64 100644
--- a/ShellPkg/Library/UefiShellLevel2CommandsLib/Cp.c
+++ b/ShellPkg/Library/UefiShellLevel2CommandsLib/Cp.c
@@ -2,7 +2,7 @@
   Main file for cp shell level 2 function.
 
   (C) Copyright 2015 Hewlett-Packard Development Company, L.P.<BR>
-  Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2009 - 2019, Intel Corporation. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -101,6 +101,9 @@ CopySingleFile(
     // possibly return based on response
     //
     if (!SilentMode) {
+      if (Response == NULL) {
+        return SHELL_ABORTED;
+      }
       switch (*(SHELL_PROMPT_RESPONSE*)Response) {
         case ShellPromptResponseNo:
           //
diff --git a/ShellPkg/Library/UefiShellLevel2CommandsLib/Mv.c b/ShellPkg/Library/UefiShellLevel2CommandsLib/Mv.c
index 8c2852d7eb..f50c1e4c20 100644
--- a/ShellPkg/Library/UefiShellLevel2CommandsLib/Mv.c
+++ b/ShellPkg/Library/UefiShellLevel2CommandsLib/Mv.c
@@ -2,7 +2,7 @@
   Main file for mv shell level 2 function.
 
   (C) Copyright 2013-2015 Hewlett-Packard Development Company, L.P.<BR>
-  Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2009 - 2019, Intel Corporation. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -637,6 +637,9 @@ ValidateAndMoveFiles(
       if (Response == NULL) {
         ShellPromptForResponseHii(ShellPromptResponseTypeYesNoAllCancel, STRING_TOKEN (STR_GEN_DEST_EXIST_OVR), gShellLevel2HiiHandle, &Response);
       }
+      if (Response == NULL) {
+        return SHELL_ABORTED;
+      }
       switch (*(SHELL_PROMPT_RESPONSE*)Response) {
         case ShellPromptResponseNo:
           FreePool(Response);
-- 
2.21.0.windows.1