Re: [PATCH] mm/vmalloc: Sanitize __get_vm_area() arguments

Peter Zijlstra
2020-04-17T13:14:35Z

On Fri, Apr 17, 2020 at 03:57:35PM +0300, Sakari Ailus wrote:
> Hi Christoph,
>
> On Mon, Apr 06, 2020 at 06:01:55AM -0700, Christoph Hellwig wrote:
> > On Fri, Apr 03, 2020 at 06:32:53PM +0200, Peter Zijlstra wrote:
> > >
> > > __get_vm_area() is an exported symbol, make sure the callers stay in
> > > the expected memory range. When calling this function with memory
> > > ranges outside of the VMALLOC range *bad* things can happen.
> > >
> > > (I noticed this when I managed to corrupt the kernel text by accident)
> >
> > Maybe it is time to unexport it? There are only two users:
> >
> > - staging/media/ipu3 really should be using vmap. And given that it
> > is a staging driver it really doesn't matter anyway if we break it.
>
> It's not very polite to suggest breaking other people's drivers for such a
> small matter, staging or not. That'd be bound to break kernel compilation
> for a lot of people, if for nothing else.
>
> Anyway, thanks for cc'ing me. I agree with suggestion and I'll submit a
> patch to address it.