Re: [PATCH 2/4] MdeModulePkg/HiiDatabaseDxe: Add check for StringPtr

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

> -----Original Message-----
> From: Zhang, Shenglei
> Sent: Thursday, October 17, 2019 11:31 AM
> To: devel@edk2.groups.io
> Cc: Bi, Dandan <dandan.bi@intel.com>; Dong, Eric <eric.dong@intel.com>
> Subject: [PATCH 2/4] MdeModulePkg/HiiDatabaseDxe: Add check for
> StringPtr
> 
> If the target string doesn't appear in the searched string, StringPtr will be
> NULL. So add a check for that.
> 
> Cc: Dandan Bi <dandan.bi@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
> ---
>  MdeModulePkg/Universal/HiiDatabaseDxe/ConfigRouting.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/MdeModulePkg/Universal/HiiDatabaseDxe/ConfigRouting.c
> b/MdeModulePkg/Universal/HiiDatabaseDxe/ConfigRouting.c
> index 71ea25bc19bf..f786da8e370a 100644
> --- a/MdeModulePkg/Universal/HiiDatabaseDxe/ConfigRouting.c
> +++ b/MdeModulePkg/Universal/HiiDatabaseDxe/ConfigRouting.c
> @@ -909,6 +909,10 @@ CompareAndMergeDefaultString (
>    // To find the <AltResp> with AltConfigHdr in AltCfgResp, ignore other
> <AltResp> which follow it.
>    //
>    StringPtr = StrStr (*AltCfgResp, AltConfigHdr);
> +  if (StringPtr == NULL) {
> +    Status = EFI_NOT_FOUND;
> +    goto Exit;
> +  }
Hi Shenglei,
I think we can add  ASSERT (StringPtr != NULL); here.
Since when call this function, the AltCfgResp and DefaultAltCfgResp must have contained the AltConfigHdr.
The caller of the CompareAndMergeDefaultString have done the check.

Thanks,
Dandan
>    StringPtrNext = StrStr (StringPtr + 1, L"&GUID");
>    if (StringPtrNext != NULL) {
>      TempCharA = *StringPtrNext;
> --
> 2.18.0.windows.1