Re: sys_kcmp

Cyrill Gorcunov
2012-09-24T18:51:25Z

On Mon, Sep 24, 2012 at 11:29:09AM -0700, Eric W. Biederman wrote:
> >
> > +#ifdef CONFIG_MMU
> > if (addr >= TASK_SIZE || addr < mmap_min_addr)
> > +#else
> > + if (addr >= TASK_SIZE)
> > +#endif
>
> I expect what you want is a call to access_ok, rather than hard coding
> details about task layout here. This test certainly looks wrong
> for a 32bit process on a 64bit kernel. If I read your test right it
> appears I can set values of say 0x100000000 on a 32bit process...
>
> As for mmap_min_addr I would expect your find_vma check would make that
> test unnecessary, simply by not finding a vma...

Good point, Eric, thanks! I'm cooking a new patch now.