Re: [PATCH 1/3] rust: add untrusted data abstraction

[Greg KH]

On Wed, Sep 18, 2024 at 05:33:33PM +0000, Benno Lossin wrote:
> On 18.09.24 19:09, Greg KH wrote:
> > On Wed, Sep 18, 2024 at 03:40:54PM +0000, Benno Lossin wrote:
> >>>> Yeah, we need more users of this to know the full way to express this
> >>>> correctly. I would like to avoid huge refactorings in the future.
> >>>
> >>> I think adding it to the copy_*_user functions we already have in
> >>> upstream, and then asking Alice to rebase binder should be a really solid
> >>> real-world testcase. And I think currently for the things in-flight
> >>> copy*user is going to be the main source of untrusted data anyway, not so
> >>> much page cache folios.
> >>
> >> Sure. I chose tarfs as the use-case, because Greg mentioned to me that
> >> it would benefit from adding this API. (I have no prior linux kernel
> >> experience, so you giving me some pointers where this will be useful is
> >> very helpful!)
> > 
> > I just had tarfs as an easy example where we were reading data off the
> > disk and acting on it, in a way just like C where if the data is
> > corrupted we can do "not normal" things.  Sorry it got tied up with
> 
> No worries! I was just under the impression that this would be common
> (maybe it's common for filesystems?), so just having that clarification
> now makes more sense.

Yes, this would be common for filesystems.