[PATCH] MdeModulePkg/CapsuleApp: Fix potential NULL pointer dereference issue

[Chen A Chen <chen.a.chen@intel.com>]

To avoid potential NULL pointer dereference issue. Initialize them at
the beginning of the function. This patch is a supplement which was missed
at e98212cb5d59fff8f385d9179ad7f1a3ce9cf215 commit.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao Wu <hao.a.wu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Chen A Chen <chen.a.chen@intel.com>
---
 MdeModulePkg/Application/CapsuleApp/CapsuleDump.c  | 23 +++++++++++++---------
 .../Application/CapsuleApp/CapsuleOnDisk.c         |  5 ++++-
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/MdeModulePkg/Application/CapsuleApp/CapsuleDump.c b/MdeModulePkg/Application/CapsuleApp/CapsuleDump.c
index 33d2ecc582..cbbfda1424 100644
--- a/MdeModulePkg/Application/CapsuleApp/CapsuleDump.c
+++ b/MdeModulePkg/Application/CapsuleApp/CapsuleDump.c
@@ -1001,12 +1001,15 @@ DumpProvisionedCapsule (
   EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *Fs;
   EFI_SHELL_PROTOCOL              *ShellProtocol;
 
-  ShellProtocol = GetShellProtocol ();
-
   Index             = 0;
   CapsuleDataPtr64  = NULL;
   BootNext          = NULL;
-  ShellProtocol     = NULL;
+
+  ShellProtocol = GetShellProtocol ();
+  if (ShellProtocol == NULL) {
+    Print (L"Get Shell Protocol Fail\n");
+    return ;
+  }
 
   //
   // Dump capsule provisioned on Memory
@@ -1033,16 +1036,16 @@ DumpProvisionedCapsule (
               (VOID **) &CapsuleDataPtr64,
               NULL
               );
-    if (EFI_ERROR (Status)) {
+    if (EFI_ERROR (Status) || CapsuleDataPtr64 == NULL) {
       if (Index == 0) {
         Print (L"No data.\n");
       }
       break;
-    } else {
-      Index++;
-      Print (L"Capsule Description at 0x%08x\n", *CapsuleDataPtr64);
-      DumpBlockDescriptors ((EFI_CAPSULE_BLOCK_DESCRIPTOR*) (UINTN) *CapsuleDataPtr64, DumpCapsuleInfo);
     }
+
+    Index++;
+    Print (L"Capsule Description at 0x%08x\n", *CapsuleDataPtr64);
+    DumpBlockDescriptors ((EFI_CAPSULE_BLOCK_DESCRIPTOR*) (UINTN) *CapsuleDataPtr64, DumpCapsuleInfo);
   }
 
   //
@@ -1057,7 +1060,9 @@ DumpProvisionedCapsule (
              (VOID **) &BootNext,
              NULL
             );
-  if (!EFI_ERROR (Status)) {
+  if (EFI_ERROR (Status) || BootNext == NULL) {
+    Print (L"Get BootNext Variable Fail. Status = %r\n", Status);
+  } else {
     UnicodeSPrint (BootOptionName, sizeof (BootOptionName), L"Boot%04x", *BootNext);
     Status = EfiBootManagerVariableToLoadOption (BootOptionName, &BootNextOptionEntry);
     if (!EFI_ERROR (Status)) {
diff --git a/MdeModulePkg/Application/CapsuleApp/CapsuleOnDisk.c b/MdeModulePkg/Application/CapsuleApp/CapsuleOnDisk.c
index 4faa863bca..f6e46cbdb1 100644
--- a/MdeModulePkg/Application/CapsuleApp/CapsuleOnDisk.c
+++ b/MdeModulePkg/Application/CapsuleApp/CapsuleOnDisk.c
@@ -445,7 +445,10 @@ GetUpdateFileSystem (
                (VOID **)&BootNextData,
                NULL
                );
-    if (!EFI_ERROR (Status)) {
+    if (EFI_ERROR (Status) || BootNextData == NULL) {
+      Print (L"Get Boot Next Data Fail. Status = %r\n", Status);
+      return EFI_NOT_FOUND;
+    } else {
       UnicodeSPrint (BootOptionName, sizeof (BootOptionName), L"Boot%04x", *BootNextData);
       Status = EfiBootManagerVariableToLoadOption (BootOptionName, &BootNextOption);
       if (!EFI_ERROR (Status)) {
-- 
2.16.2.windows.1