Re: [Qemu-devel] Buggy SDL Zoom

[Stefano Stabellini]

On Wed, 12 Oct 2011, Stefan Weil wrote:
> Hi,
> 
> the SDL zoom feature which is implemented in sdl_zoom_template.h
> (and the SDL_rotozoom version which it is based on) accesses memory
> beyond the allocated limits.
> 
> This can be easily reproduced using Valgrind and some Linux desktop
> which resizes QEMU's window to fill the whole screen (I did run the tests
> on an Ubuntu netbook).
> 
> Another effect can be observed by repeatedly increasing the zoom factor
> with the Alt-Ctrl-+: the image grows up to a certain value and then
> collapses again.
> 
> It looks like other programs using SDL_rotozoom also discovered
> out-of-bound problems, and in newer versions, the SDL_rotozoom
> code was totally rewritten.
> 
> For security reasons, I suggest disabling the zoom feature until
> either the current code is replaced by a (tested) newer version
> of SDL_rotozoom or fixed.

I am OK with that.