Re: [PATCH v3 2/3] ShellPkg: Fix misuses of AllocateCopyPool

["Carsey, Jaben" <jaben.carsey@intel.com>]

Why not use the StrCpy_s function to copy strings?  CopyMem and StrSize feels odd to me.

> -----Original Message-----
> From: Wang, Jian J
> Sent: Tuesday, November 07, 2017 6:12 PM
> To: edk2-devel@lists.01.org
> Cc: Carsey, Jaben <jaben.carsey@intel.com>; Ni, Ruiyu
> <ruiyu.ni@intel.com>; Bi, Dandan <dandan.bi@intel.com>
> Subject: [PATCH v3 2/3] ShellPkg: Fix misuses of AllocateCopyPool
> Importance: High
> 
> > v3:
> >   No update
> 
> > v2:
> > a. Use ReallocatePool instead of allocating then copying wherever
> applicable
> 
> AllocateCopyPool(AllocationSize, *Buffer) will copy "AllocationSize" bytes of
> memory from old "Buffer" to new allocated one. If "AllocationSize" is bigger
> than size of "Buffer", heap memory overflow occurs during copy.
> 
> One solution is to allocate pool first then copy the necessary bytes to new
> memory. Another is using ReallocatePool instead if old buffer will be freed
> on spot.
> 
> Cc: Jaben Carsey <jaben.carsey@intel.com>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Bi Dandan <dandan.bi@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
> ---
>  ShellPkg/Application/Shell/Shell.c                                 | 4 +++-
>  ShellPkg/Library/UefiShellBcfgCommandLib/UefiShellBcfgCommandLib.c | 7
> +++++--
>  2 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/ShellPkg/Application/Shell/Shell.c
> b/ShellPkg/Application/Shell/Shell.c
> index 5471930ba1..656206fdce 100644
> --- a/ShellPkg/Application/Shell/Shell.c
> +++ b/ShellPkg/Application/Shell/Shell.c
> @@ -1646,7 +1646,7 @@ ShellConvertVariables (
>    //
>    // now do the replacements...
>    //
> -  NewCommandLine1 = AllocateCopyPool(NewSize, OriginalCommandLine);
> +  NewCommandLine1 = AllocateZeroPool (NewSize);
>    NewCommandLine2 = AllocateZeroPool(NewSize);
>    ItemTemp        = AllocateZeroPool(ItemSize+(2*sizeof(CHAR16)));
>    if (NewCommandLine1 == NULL || NewCommandLine2 == NULL ||
> ItemTemp == NULL) {
> @@ -1655,6 +1655,8 @@ ShellConvertVariables (
>      SHELL_FREE_NON_NULL(ItemTemp);
>      return (NULL);
>    }
> +  CopyMem (NewCommandLine1, OriginalCommandLine, StrSize
> (OriginalCommandLine));
> +
>    for (MasterEnvList = EfiShellGetEnv(NULL)
>      ;  MasterEnvList != NULL && *MasterEnvList != CHAR_NULL
>      ;  MasterEnvList += StrLen(MasterEnvList) + 1
> diff --git
> a/ShellPkg/Library/UefiShellBcfgCommandLib/UefiShellBcfgCommandLib.c
> b/ShellPkg/Library/UefiShellBcfgCommandLib/UefiShellBcfgCommandLib.c
> index 1122c89b8b..ee3db63358 100644
> ---
> a/ShellPkg/Library/UefiShellBcfgCommandLib/UefiShellBcfgCommandLib.c
> +++
> b/ShellPkg/Library/UefiShellBcfgCommandLib/UefiShellBcfgCommandLib.c
> @@ -143,10 +143,11 @@ UpdateOptionalData(
>      OriginalOptionDataSize += (*(UINT16*)(OriginalData + sizeof(UINT32)));
>      OriginalOptionDataSize -= OriginalSize;
>      NewSize = OriginalSize - OriginalOptionDataSize + DataSize;
> -    NewData = AllocateCopyPool(NewSize, OriginalData);
> +    NewData = AllocatePool(NewSize);
>      if (NewData == NULL) {
>        Status = EFI_OUT_OF_RESOURCES;
>      } else {
> +      CopyMem (NewData, OriginalData, OriginalSize -
> OriginalOptionDataSize);
>        CopyMem(NewData + OriginalSize - OriginalOptionDataSize, Data,
> DataSize);
>      }
>    }
> @@ -1120,11 +1121,13 @@ BcfgAddOpt(
>          // Now we know how many EFI_INPUT_KEY structs we need to attach to
> the end of the EFI_KEY_OPTION struct.
>          // Re-allocate with the added information.
>          //
> -        KeyOptionBuffer = AllocateCopyPool(sizeof(EFI_KEY_OPTION) +
> (sizeof(EFI_INPUT_KEY) * NewKeyOption.KeyData.Options.InputKeyCount),
> &NewKeyOption);
> +        KeyOptionBuffer = AllocatePool (sizeof(EFI_KEY_OPTION) +
> (sizeof(EFI_INPUT_KEY) *
> NewKeyOption.KeyData.Options.InputKeyCount));
>          if (KeyOptionBuffer == NULL) {
>            ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_NO_MEM),
> gShellBcfgHiiHandle, L"bcfg");
>            ShellStatus = SHELL_OUT_OF_RESOURCES;
> +          return ShellStatus;
>          }
> +        CopyMem (KeyOptionBuffer, &NewKeyOption,
> sizeof(EFI_KEY_OPTION));
>        }
>        for (LoopCounter = 0 ; ShellStatus == SHELL_SUCCESS && LoopCounter <
> NewKeyOption.KeyData.Options.InputKeyCount; LoopCounter++) {
>          //
> --
> 2.14.1.windows.1