Re: [patch 2/2] MdeModulePkg/DisplayEngine: Zero memory before free (CVE-2019-14558)

["Wang, Jian J" <jian.j.wang@intel.com>]

Please update copyright year for patch 1 and 2. With it addressed,

Reviewed-by: Jian J Wang <jian.j.wang@intel.com>

Regards,
Jian

> -----Original Message-----
> From: Bi, Dandan <dandan.bi@intel.com>
> Sent: Thursday, February 13, 2020 12:03 PM
> To: devel@edk2.groups.io
> Cc: Gao, Liming <liming.gao@intel.com>; Dong, Eric <eric.dong@intel.com>;
> Wang, Jian J <jian.j.wang@intel.com>
> Subject: [patch 2/2] MdeModulePkg/DisplayEngine: Zero memory before free
> (CVE-2019-14558)
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1611
> 
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Signed-off-by: Dandan Bi <dandan.bi@intel.com>
> ---
>  MdeModulePkg/Universal/DisplayEngineDxe/ProcessOptions.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/MdeModulePkg/Universal/DisplayEngineDxe/ProcessOptions.c
> b/MdeModulePkg/Universal/DisplayEngineDxe/ProcessOptions.c
> index 7d9486112b..1087004939 100644
> --- a/MdeModulePkg/Universal/DisplayEngineDxe/ProcessOptions.c
> +++ b/MdeModulePkg/Universal/DisplayEngineDxe/ProcessOptions.c
> @@ -821,10 +821,11 @@ PasswordProcess (
>      //
>      // Old password exist, ask user for the old password
>      //
>      Status = ReadString (MenuOption, gPromptForPassword, StringPtr);
>      if (EFI_ERROR (Status)) {
> +      ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
>        FreePool (StringPtr);
>        return Status;
>      }
> 
>      //
> @@ -838,11 +839,11 @@ PasswordProcess (
>          //
>          PasswordInvalid ();
>        } else {
>          Status = EFI_SUCCESS;
>        }
> -
> +      ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
>        FreePool (StringPtr);
>        return Status;
>      }
>    }
> 
> @@ -854,10 +855,11 @@ PasswordProcess (
>    if (EFI_ERROR (Status)) {
>      //
>      // Reset state machine for password
>      //
>      Question->PasswordCheck (gFormData, Question, NULL);
> +    ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
>      FreePool (StringPtr);
>      return Status;
>    }
> 
>    //
> @@ -869,10 +871,12 @@ PasswordProcess (
>    if (EFI_ERROR (Status)) {
>      //
>      // Reset state machine for password
>      //
>      Question->PasswordCheck (gFormData, Question, NULL);
> +    ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
> +    ZeroMem (TempString, (Maximum + 1) * sizeof (CHAR16));
>      FreePool (StringPtr);
>      FreePool (TempString);
>      return Status;
>    }
> 
> --
> 2.18.0.windows.1