Re: [PATCH 0/3] MR3839: kernel32: Add structure size checks to CreateActCtx().

[Alexandre Julliard (＠julliard)]

On Fri Oct 13 20:21:09 2023 +0000, Nikolay Sivov wrote:
> I was thinking about doing it like this:
>  443     size = FIELD_OFFSET(ACTCTXA, wProcessorArchitecture);
>  444     if (actctx->dwFlags & ACTCTX_FLAG_PROCESSOR_ARCHITECTURE_VALID)
>  445         size = max(size, FIELD_OFFSET(ACTCTXA, wLangId));
>  446     if (actctx->dwFlags & ACTCTX_FLAG_LANGID_VALID)
>  447         size = max(size, FIELD_OFFSET(ACTCTXA, lpAssemblyDirectory));
>  448     if (actctx->dwFlags & ACTCTX_FLAG_ASSEMBLY_DIRECTORY_VALID)
>  449         size = max(size, FIELD_OFFSET(ACTCTXA, lpResourceName));
>  450     if (actctx->dwFlags & ACTCTX_FLAG_RESOURCE_NAME_VALID)
>  451         size = max(size, FIELD_OFFSET(ACTCTXA, lpApplicationName));
>  452     if (actctx->dwFlags & ACTCTX_FLAG_APPLICATION_NAME_VALID)
>  453         size = max(size, FIELD_OFFSET(ACTCTXA, hModule));
>  454     if (actctx->dwFlags & ACTCTX_FLAG_HMODULE_VALID)
>  455         size = sizeof(ACTCTXA);
>  456     if (actctx->cbSize < size)
>  457     {
>  458         SetLastError(ERROR_INVALID_PARAMETER);
>  459         return INVALID_HANDLE_VALUE;
>  460     }
>
> Then duplicating exactly the same check in CreateActCtxW(), structure
> layout is the same. This way we won't need six size checks and six
> jumps, times two.
> Thanks for the bug report (https://bugs.winehq.org/show_bug.cgi?id=55782).

You could even use an array of flags and their corresponding sizes.