[Bug 58782] New: Crash or freeze when draw elliptic regions

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=58782

Bug ID: 58782
           Summary: Crash or freeze when draw elliptic regions
           Product: Wine
           Version: 10.0
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: win32u
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 79427
  --> http://bugs.winehq.org/attachment.cgi?id=79427
patch and examples

When i'm passing big values to elliptic regions functions or to rounded rects
functions, wine is crashing or freezing.

Usually we don't need to paint such large shapes, but they can be produced by
an application during pan&zoom. Mostly they are out of screen and we don't need
to it to draw them properly. But we need to avoid freezing or crash.

Following commands reproduce the bug (example c-code in attachment):

// freeze on this command (test1.c):
CreateEllipticRgn(0, 4, -600000000, 0);

// crash on this (test1.c):
CreateEllipticRgn(0, 4, -600000000, 0);

// freeze too (test2.c):
RoundRect(dc, -534431263, -25344, -108065219, -9065, 426366044, 16279);

I've learned the wine sources and found several issues:

1. In file dlls/win32u/region.c in function NtGdiCreateRoundRectRgn:

There are several possible int and even int64 overflows
To make things work properly `ellipse_width` and `ellipse_height` should be
restricted  by at least 2^19.

Also here can be out-of-memory issues, because this function tries to allocate
allocates `ellipse_height` rectangles. So, to prevent freezing or memory issues
will be better to restrict `ellipse_height` to smaller number.

2. In file dlls/win32u/dibdrv/graphics.c in function dibdrv_RoundRect:

There (ellipse_width + ellipse_height)*16 bytes are allocating.

So, we need to restrict to restrict values of `ellipse_width` and
`ellipse_height`. For example, to 2^19 to be in consistent with
NtGdiCreateRoundRectRgn.

I've attached a patch-file (round-rect.patch) that solves the problem.