[edk2-devel][Patch] MdeModulePkg/DxeCapsuleLibFmp: Add missing NULL pointer check.

["Xu, Wei6" <wei6.xu@intel.com>]

Add missing NULL pointer check for CapsuleNameBufStart.
Also add comments to notice that capsule name integrity check assumes
the capsule has been validated by IsValidCapsuleHeader().

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Chao B Zhang <chao.b.zhang@intel.com>
Signed-off-by: Wei6 Xu <wei6.xu@intel.com>
---
 MdeModulePkg/Library/DxeCapsuleLibFmp/CapsuleOnDisk.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/MdeModulePkg/Library/DxeCapsuleLibFmp/CapsuleOnDisk.c b/MdeModulePkg/Library/DxeCapsuleLibFmp/CapsuleOnDisk.c
index 66c9be8e1f..3193ca8f4d 100644
--- a/MdeModulePkg/Library/DxeCapsuleLibFmp/CapsuleOnDisk.c
+++ b/MdeModulePkg/Library/DxeCapsuleLibFmp/CapsuleOnDisk.c
@@ -23,10 +23,13 @@ IsCapsuleNameCapsule (
 
 /**
   Check the integrity of the capsule name capsule.
   If the capsule is vaild, return the physical address of each capsule name string.
 
+  This routine assumes the capsule has been validated by IsValidCapsuleHeader(), so
+  capsule memory overflow is not going to happen in this routine.
+
   @param[in]  CapsuleHeader   Pointer to the capsule header of a capsule name capsule.
   @param[out] CapsuleNameNum  Number of capsule name.
 
   @retval NULL                Capsule name capsule is not valid.
   @retval CapsuleNameBuf      Array of capsule name physical address.
@@ -63,10 +66,13 @@ ValidateCapsuleNameCapsuleIntegrity (
   //
   // If strings are not aligned on a 16-bit boundary, reallocate memory for it.
   //
   if (((UINTN) CapsuleNameBufStart & BIT0) != 0) {
     CapsuleNameBufStart = AllocateCopyPool (CapsuleHeader->CapsuleImageSize - CapsuleHeader->HeaderSize, CapsuleNameBufStart);
+    if (CapsuleNameBufStart == NULL) {
+      return NULL;
+    }
   }
 
   CapsuleNameBufEnd = CapsuleNameBufStart + CapsuleHeader->CapsuleImageSize - CapsuleHeader->HeaderSize;
 
   CapsuleNamePtr = CapsuleNameBufStart;
-- 
2.16.2.windows.1