Re: nvdimm crash at boot

[Dan Williams]

On Tue, Jan 8, 2019 at 3:55 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> On Tue, Jan 8, 2019 at 3:54 PM Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> >
> > On Tue, Jan 8, 2019 at 3:34 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> > >
> > > On Tue, Jan 8, 2019 at 3:28 PM Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> > > > Ah, thanks for the report! The key difference is that you don't define
> > > > a "label area", so the driver bails out early and never initializes
> > > > the security state.
> > > >
> > > > This should fix it up.
> > > >
> > > > diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
> > > > index 4890310df874..636cdb06ee17 100644
> > > > --- a/drivers/nvdimm/dimm_devs.c
> > > > +++ b/drivers/nvdimm/dimm_devs.c
> > > > @@ -514,7 +514,7 @@ static umode_t nvdimm_visible(struct kobject
> > > > *kobj, struct attribute *a, int n)
> > > >
> > > >         if (a != &dev_attr_security.attr)
> > > >                 return a->mode;
> > > > -       if (nvdimm->sec.state < 0)
> > > > +       if (!nvdimm->sec.ops || nvdimm->sec.state < 0)
> > > >                 return 0;
> > > >         /* Are there any state mutation ops? */
> > > >         if (nvdimm->sec.ops->freeze || nvdimm->sec.ops->disable
> > >
> > > Okay, cool. I wasn't sure if that test needed a deeper check. :)
> > >
> > > Fixes: 37833fb7989a9 ("acpi/nfit, libnvdimm: Add freeze security
> > > support to Intel nvdimm")
> > > Tested-by: Kees Cook <keescook@xxxxxxxxxxxx>
> > >
> >
> > Actually, looking closer this should have been avoided by the fact
> > that __nvdimm_create() initializes the security state early and that
> > nvdimm->sec.state should have saved us.
> >
> > I'll dig a bit deeper with your qemu config.
>
> Maybe something goes weird with pstore stealing the region?

No, pstore is off the hook. I was just able to reproduce locally and
I'm not doing anything with pstore.