Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <CAGXu5jKUP9o-ZgW5Wa5-9DHeQNZ5VA3cLBCJ0P7AVkTQ5tqHtQ@mail.gmail.com>
 <CAPcyv4iZZEM3D8vta_sge7a4iMgPZ5a1AnunXa4DKUaWauZk1g@mail.gmail.com>
 <CAGXu5j+z_yRPgE0HO=Sjo_VwwDDPJ+VLxbxwKgbb2cUAB5jmwg@mail.gmail.com>
 <CAPcyv4jhFGMzBrWHS_9q0Fe2MersRXz31VG3H2dJfujx1CJGhQ@mail.gmail.com> <CAGXu5jKrhvUduv_XUYF94YM=bBfPGNkPrZ_EkvRKB0pDY_6uOw@mail.gmail.com>
In-Reply-To: <CAGXu5jKrhvUduv_XUYF94YM=bBfPGNkPrZ_EkvRKB0pDY_6uOw@mail.gmail.com>
From:   Dan Williams <dan.j.williams@intel.com>
Date:   Tue, 8 Jan 2019 16:02:05 -0800
Message-ID: <CAPcyv4jQ1Og_mEVjb77xdM263MugzK7_yrR_zi498JFrOrhSrg@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>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, Jan 8, 2019 at 3:55 PM Kees Cook <keescook@chromium.org> wrote:
>
> On Tue, Jan 8, 2019 at 3:54 PM Dan Williams <dan.j.williams@intel.com> wrote:
> >
> > 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.
>
> 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.