Re: [PATCH] MdeModulePkg DxeCore: Only free ScratchBuffer when it is not NULL

["Gao, Liming" <liming.gao@intel.com>]

Good catch. Reviewed-by: Liming Gao <liming.gao@intel.com>

>-----Original Message-----
>From: Zeng, Star
>Sent: Friday, June 23, 2017 5:45 PM
>To: edk2-devel@lists.01.org
>Cc: Zeng, Star <star.zeng@intel.com>; Gao, Liming <liming.gao@intel.com>
>Subject: [PATCH] MdeModulePkg DxeCore: Only free ScratchBuffer when it is
>not NULL
>
>There is a case that ExtractGuidedSectionGetInfo return 0 for
>ScratchBufferSize and ScratchBuffer will be NULL, after AllocatePool
>fails to allocate buffer for AllocatedOutputBuffer, the code will
>call FreePool (ScratchBuffer), but ScratchBuffer == NULL.
>
>This patch is to only free ScratchBuffer when it is not NULL.
>
>Cc: Liming Gao <liming.gao@intel.com>
>Contributed-under: TianoCore Contribution Agreement 1.0
>Signed-off-by: Star Zeng <star.zeng@intel.com>
>---
> MdeModulePkg/Core/Dxe/SectionExtraction/CoreSectionExtraction.c | 6
>++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
>diff --git
>a/MdeModulePkg/Core/Dxe/SectionExtraction/CoreSectionExtraction.c
>b/MdeModulePkg/Core/Dxe/SectionExtraction/CoreSectionExtraction.c
>index 6622eeeaf161..9561ae176655 100644
>--- a/MdeModulePkg/Core/Dxe/SectionExtraction/CoreSectionExtraction.c
>+++ b/MdeModulePkg/Core/Dxe/SectionExtraction/CoreSectionExtraction.c
>@@ -27,7 +27,7 @@
>   3) A support protocol is not found, and the data is not available to be read
>      without it.  This results in EFI_PROTOCOL_ERROR.
>
>-Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
>+Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
> This program and the accompanying materials
> are licensed and made available under the terms and conditions of the BSD
>License
> which accompanies this distribution.  The full text of the license may be found
>at
>@@ -1551,7 +1551,9 @@ CustomGuidedSectionExtract (
>     //
>     AllocatedOutputBuffer = AllocatePool (OutputBufferSize);
>     if (AllocatedOutputBuffer == NULL) {
>-      FreePool (ScratchBuffer);
>+      if (ScratchBuffer != NULL) {
>+        FreePool (ScratchBuffer);
>+      }
>       return EFI_OUT_OF_RESOURCES;
>     }
>     *OutputBuffer = AllocatedOutputBuffer;
>--
>2.7.0.windows.1