Re: [PATCH] mm/vmalloc: Sanitize __get_vm_area() arguments
From: Sakari Ailus
Date: Fri Apr 17 2020 - 08:57:43 EST
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.
--
Regards,
Sakari Ailus