Re: [PULL] vhost: cleanups and fixes

From: Michael S. Tsirkin
Date: Fri Nov 30 2018 - 14:55:48 EST


On Fri, Nov 30, 2018 at 11:01:03AM -0800, Bijan Mottahedeh wrote:
> On 11/30/2018 5:44 AM, Michael S. Tsirkin wrote:
> > On Thu, Nov 01, 2018 at 04:06:19PM -0700, Linus Torvalds wrote:
> > > On Thu, Nov 1, 2018 at 4:00 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> > > > + memset(&rsp, 0, sizeof(rsp));
> > > > + rsp.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
> > > > + resp = vq->iov[out].iov_base;
> > > > + ret = __copy_to_user(resp, &rsp, sizeof(rsp));
> > > >
> > > > Is it actually safe to trust that iov_base has passed an earlier
> > > > access_ok() check here? Why not just use copy_to_user() instead?
> > > Good point.
> > >
> > > We really should have removed those double-underscore things ages ago.
> > >
> > > Also, apart from the address, what about the size? Wouldn't it be
> > > better to use copy_to_iter() rather than implement it badly by hand?
> > >
> > > Linus
> > Bijan can you respond please?
> > Are you going to look into this and convert code to copy_to_iter?
> > I don't think we should release Linux like this, so if you don't
> > have the time I'd rather revert for now and you can look
> > into reposting for the next release.
> >
> > Thanks,
> >
>
> Sure, will do.  Can I send an individual patch for the fix to
> vhost_scsi_send_tmf_reject()?
>
> Thanks.
>
> --bijan

Please go ahead.

--
MST