Re: [patch] BaseTools/VfrCompile: Avoid using uninitialized pointer

["Bi, Dandan" <dandan.bi@intel.com>]

Thanks for your test work. 
I have created a V2 patch which make the code logic more clean. Would you mind to try the V2 patch in your environment?


Thanks,
Dandan

-----Original Message-----
From: Gary Lin [mailto:glin@suse.com] 
Sent: Wednesday, May 9, 2018 10:32 AM
To: Bi, Dandan <dandan.bi@intel.com>
Cc: edk2-devel@lists.01.org; Dong, Eric <eric.dong@intel.com>; Gao, Liming <liming.gao@intel.com>
Subject: Re: [edk2] [patch] BaseTools/VfrCompile: Avoid using uninitialized pointer

On Tue, May 08, 2018 at 07:46:19PM +0800, Dandan Bi wrote:
> _CLEAR_SAVED_OPHDR () is used for initialize the variables.
> We should not update it to free memory.
> It will cause some pointer used before initialization.
> This patch is to fix this issue.
> 
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Dandan Bi <dandan.bi@intel.com>
> ---
>  BaseTools/Source/C/VfrCompile/VfrSyntax.g | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/BaseTools/Source/C/VfrCompile/VfrSyntax.g 
> b/BaseTools/Source/C/VfrCompile/VfrSyntax.g
> index 4b0a43606ea..cc042ab4307 100644
> --- a/BaseTools/Source/C/VfrCompile/VfrSyntax.g
> +++ b/BaseTools/Source/C/VfrCompile/VfrSyntax.g
> @@ -4103,12 +4103,15 @@ vfrStatementExpression [UINT32 RootLevel, UINT32 ExpOpCount = 0] :
>                                                                }
>                                                              }
>                                                            }
>                                                            
>                                                            if ($RootLevel == 0) {
> -                                                            _CLEAR_SAVED_OPHDR ();
> -                                                            mCIfrOpHdrIndex --;
> +                                                            if (mCIfrOpHdr[mCIfrOpHdrIndex] != NULL) {
> +                                                              delete mCIfrOpHdr[mCIfrOpHdrIndex];
> +                                                              mCIfrOpHdr[mCIfrOpHdrIndex] = NULL;
> +                                                            }

> +                                                             
> + mCIfrOpHdrIndex --;
An extra space was added.

>                                                            }
>                                                         >>
>    ;
>  
>  //
> @@ -5082,14 +5085,11 @@ EfiVfrParser::_SAVE_OPHDR_COND (  VOID  
> EfiVfrParser::_CLEAR_SAVED_OPHDR (
>    VOID
>    )
>  {
> -  if (mCIfrOpHdr[mCIfrOpHdrIndex] != NULL) {
> -    delete mCIfrOpHdr[mCIfrOpHdrIndex];
> -    mCIfrOpHdr[mCIfrOpHdrIndex]     = NULL;
> -  }
> +  mCIfrOpHdr[mCIfrOpHdrIndex]       = NULL;
>    mCIfrOpHdrLineNo[mCIfrOpHdrIndex] = 0;  }
>  
>  BOOLEAN
>  EfiVfrParser::_SET_SAVED_OPHDR_SCOPE (
> --
I applied the patch and triggered the rebuild of ovmf. It's now built on all versions and arch.

Thanks for fixing it.

Tested-by: Gary Lin <glin@suse.com>

> 2.14.3.windows.1
> 
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