From: Hao Wu <hao.a.wu@intel.com>
Date: Mon, 30 Jul 2018 05:20:13 +0000 (+0800)
Subject: UefiCpuPkg/PiSmmCpuDxeSmm: Avoid possible NULL ptr dereference
X-Git-Tag: edk2-stable201903~1315
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=6d9a0a9420167a87d353b53b93fec17ad61b4b61

UefiCpuPkg/PiSmmCpuDxeSmm: Avoid possible NULL ptr dereference

Within function GetUefiMemoryAttributesTable(), add a check to avoid
possible null pointer dereference.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
---

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
index 7d99f23426..684b14dc28 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
@@ -1098,7 +1098,7 @@ GetUefiMemoryAttributesTable (
   UINTN                        MemoryAttributesTableSize;
 
   Status = EfiGetSystemConfigurationTable (&gEfiMemoryAttributesTableGuid, (VOID **)&MemoryAttributesTable);
-  if (!EFI_ERROR (Status)) {
+  if (!EFI_ERROR (Status) && (MemoryAttributesTable != NULL)) {
     MemoryAttributesTableSize = sizeof(EFI_MEMORY_ATTRIBUTES_TABLE) + MemoryAttributesTable->DescriptorSize * MemoryAttributesTable->NumberOfEntries;
     mUefiMemoryAttributesTable = AllocateCopyPool (MemoryAttributesTableSize, MemoryAttributesTable);
     ASSERT (mUefiMemoryAttributesTable != NULL);