[Bug 2849] New: potential memory leak in server/window.c, function get_visible_region()

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=2849

Summary: potential memory leak in server/window.c, function
                    get_visible_region()
           Product: Wine
           Version: 20050310
          Platform: Other
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: wine-kernel
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

I am a researcher with the Stanford Checking group.

I am performing experiments of our static analysis tool by running it on Wine.

There is a potential memory leak in server/window.c, function get_visible_region().

LINE: 712
--> create_empty_region() transitively calls malloc(), acquiring memory
--> from the heap
    if (top && top != win && (tmp = create_empty_region()) != NULL)
    {
        offset_region( region, offset_x, offset_y );  /* make it .. */
        while (win != top && win->parent)
        {
            if (win->style & WS_CLIPSIBLINGS)
            {

--> here a NULL value returned by clip_children can trigger "goto error",
--> which does not free the region stored in "tmp"

if (!clip_children( win->parent, win, region, 0, 0 ))
                  goto error;
                if (is_region_empty( region )) break;
            }

COMMENT: It is not clear to me if clip_children can return NULL under a
different case than high memory pressure (it creates a region itself; if that
fails it returns NULL).  I am not very familiar with the Wine code base.