[PATCH 0/2] Avoid possible NULL ptr dereference

[PATCH 0/2] Avoid possible NULL ptr dereference

[Hao Wu]

Cc: Jiewen Yao <jiewen.yao@intel.com>

Hao Wu (2):
  MdePkg/SmmMemLib: Avoid possible NULL ptr dereference
  UefiCpuPkg/PiSmmCpuDxeSmm: Avoid possible NULL ptr dereference

 MdePkg/Library/SmmMemLib/SmmMemLib.c               | 2 +-
 UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

-- 
2.12.0.windows.1

[PATCH 1/2] MdePkg/SmmMemLib: Avoid possible NULL ptr dereference

[Hao Wu]

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

Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
---
 MdePkg/Library/SmmMemLib/SmmMemLib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MdePkg/Library/SmmMemLib/SmmMemLib.c b/MdePkg/Library/SmmMemLib/SmmMemLib.c
index 3409ddf87c..3e458417de 100644
--- a/MdePkg/Library/SmmMemLib/SmmMemLib.c
+++ b/MdePkg/Library/SmmMemLib/SmmMemLib.c
@@ -439,7 +439,7 @@ SmmMemLibInternalGetUefiMemoryAttributesTable (
   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;
     mSmmMemLibMemoryAttributesTable = AllocateCopyPool (MemoryAttributesTableSize, MemoryAttributesTable);
     ASSERT (mSmmMemLibMemoryAttributesTable != NULL);
-- 
2.12.0.windows.1

[PATCH 2/2] UefiCpuPkg/PiSmmCpuDxeSmm: Avoid possible NULL ptr dereference

[Hao Wu]

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

Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
index 7d99f23426..bae2423de8 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);
-- 
2.12.0.windows.1

Re: [PATCH 0/2] Avoid possible NULL ptr dereference

[Yao, Jiewen]

Seems good.

It might be better to use "if (!EFI_ERROR (Status) && (MemoryAttributesTable != NULL)) {"

Reviewed-by: Jiewen.yao@intel.com


> -----Original Message-----
> From: Wu, Hao A
> Sent: Monday, July 30, 2018 1:37 PM
> To: edk2-devel@lists.01.org
> Cc: Wu, Hao A <hao.a.wu@intel.com>; Yao, Jiewen <jiewen.yao@intel.com>
> Subject: [PATCH 0/2] Avoid possible NULL ptr dereference
> 
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> 
> Hao Wu (2):
>   MdePkg/SmmMemLib: Avoid possible NULL ptr dereference
>   UefiCpuPkg/PiSmmCpuDxeSmm: Avoid possible NULL ptr dereference
> 
>  MdePkg/Library/SmmMemLib/SmmMemLib.c               | 2 +-
>  UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> --
> 2.12.0.windows.1

Re: [PATCH 0/2] Avoid possible NULL ptr dereference

[Wu, Hao A]

> -----Original Message-----
> From: Yao, Jiewen
> Sent: Monday, July 30, 2018 3:25 PM
> To: Wu, Hao A; edk2-devel@lists.01.org
> Cc: Yao, Jiewen
> Subject: RE: [PATCH 0/2] Avoid possible NULL ptr dereference
> 
> Seems good.
> 
> It might be better to use "if (!EFI_ERROR (Status) &&
> (MemoryAttributesTable != NULL)) {"

Yes. I will update the it when pushing the patch.

Best Regards,
Hao Wu

> 
> Reviewed-by: Jiewen.yao@intel.com
> 
> 
> > -----Original Message-----
> > From: Wu, Hao A
> > Sent: Monday, July 30, 2018 1:37 PM
> > To: edk2-devel@lists.01.org
> > Cc: Wu, Hao A <hao.a.wu@intel.com>; Yao, Jiewen <jiewen.yao@intel.com>
> > Subject: [PATCH 0/2] Avoid possible NULL ptr dereference
> >
> > Cc: Jiewen Yao <jiewen.yao@intel.com>
> >
> > Hao Wu (2):
> >   MdePkg/SmmMemLib: Avoid possible NULL ptr dereference
> >   UefiCpuPkg/PiSmmCpuDxeSmm: Avoid possible NULL ptr dereference
> >
> >  MdePkg/Library/SmmMemLib/SmmMemLib.c               | 2 +-
> >  UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > --
> > 2.12.0.windows.1