Re: [PATCH 5/5] libnvdimm: address state where dimm is unlocked in preOS

[Dan Williams <dan.j.williams@intel.com>]

On Fri, Oct 12, 2018 at 11:24 AM Dave Jiang <dave.jiang@intel.com> wrote:
>
> When the nvdimm security state is unlocked during unlock, we skip the
> operation. In this state, we are not able to fetch a key for verification
> and at the same time the dimm is unlocked. This prevents us from doing
> any security operations. We will send the freeze security DSM to make the
> state consistent.
>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/nvdimm/security.c |   15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c
> index 7b5d7c77514d..6c5423228b31 100644
> --- a/drivers/nvdimm/security.c
> +++ b/drivers/nvdimm/security.c
> @@ -250,8 +250,19 @@ int nvdimm_security_unlock_dimm(struct nvdimm *nvdimm)
>         if (!nvdimm->security_ops)
>                 return 0;
>
> -       if (nvdimm->state == NVDIMM_SECURITY_UNLOCKED ||
> -                       nvdimm->state == NVDIMM_SECURITY_UNSUPPORTED ||
> +       /*
> +        * If the pre-OS has unlocked the DIMM, we will not be able to
> +        * verify the key against the hardware. Therefore we will not
> +        * retrieve the key and will freeze the security config. This will
> +        * prevent any other security operations.
> +        */

I think we should try to retrieve the key if the DIMM is unlocked and
verify it with a 'change-key-to-self' check. If either of those steps
fail then freeze the dimm.
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