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From:   Dan Williams <dan.j.williams@intel.com>
Date:   Tue, 8 Jan 2019 15:53:50 -0800
Message-ID: <CAPcyv4jhFGMzBrWHS_9q0Fe2MersRXz31VG3H2dJfujx1CJGhQ@mail.gmail.com>
Subject: Re: nvdimm crash at boot
To:     Kees Cook <keescook@chromium.org>
Cc:     Dave Jiang <dave.jiang@intel.com>,
        linux-nvdimm <linux-nvdimm@lists.01.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Tue, Jan 8, 2019 at 3:34 PM Kees Cook <keescook@chromium.org> wrote:
>
> On Tue, Jan 8, 2019 at 3:28 PM Dan Williams <dan.j.williams@intel.com> 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@chromium.org>
>

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.