[PATCH 1/5] ddraw: Protect against invalid clipper pointers.

[Henri Verbeet]

On Mon, 4 Mar 2019 at 23:29, Stefan Dösinger <stefan at codeweavers.com> wrote:
>
> Signed-off-by: Stefan Dösinger <stefan at codeweavers.com>
> ---
>  dlls/ddraw/clipper.c       | 66 +++++++++++++++++++++++++++++++++++---
>  dlls/ddraw/ddraw_private.h |  1 +
>  2 files changed, 63 insertions(+), 4 deletions(-)
>
That's pretty ugly.

Would it work to introduce a helper along the lines of the floowing?

    static BOOL ddraw_clipper_is_valid(struct ddraw_clipper *clipper)
    {
        return !IsBadReadPtr(clipper, sizeof(*clipper))
                && clipper->IDirectDrawClipper_iface.lpVtbl ==
&ddraw_clipper_vtbl;
    }