Re: [PATCH v5 04/12] nfit/libnvdimm: add unlock of nvdimm support for Intel DIMMs

[Eric Biggers <ebiggers3@gmail.com>]

Again, just a couple superficial comments:

On Tue, Jul 17, 2018 at 01:54:26PM -0700, Dave Jiang wrote:
> Add support to allow query the security status of the Intel nvdimms and
> also unlock the dimm via the kernel key management APIs. The passphrase is
> expected to be pulled from userspace through keyutils. Moving the Intel
> related bits to its own source file as well.
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/acpi/nfit/Makefile |    1 
>  drivers/acpi/nfit/core.c   |    3 +
>  drivers/acpi/nfit/intel.c  |  151 ++++++++++++++++++++++++++++++++++++++++++++
>  drivers/acpi/nfit/intel.h  |   16 +++++
>  drivers/nvdimm/dimm.c      |    7 ++
>  drivers/nvdimm/dimm_devs.c |  108 +++++++++++++++++++++++++++++++
>  drivers/nvdimm/nd-core.h   |    2 +
>  drivers/nvdimm/nd.h        |    2 +
>  include/linux/libnvdimm.h  |   23 ++++++-
>  9 files changed, 310 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/acpi/nfit/intel.c
[...]
> +
> +struct nvdimm_security_ops intel_security_ops = {
> +	.state = intel_dimm_security_state,
> +	.unlock = intel_dimm_security_unlock,
> +};

nvdimm_security_ops should be marked 'const'.

> +/*
> + * Find key in kernel keyring
> + */
> +static struct key *nvdimm_search_key(struct device *dev)
> +{
> +	struct nvdimm *nvdimm = to_nvdimm(dev);
> +	char *desc;
> +	key_ref_t keyref;
> +	struct key *key = NULL;
> +
> +	if (!nvdimm->security_ops)
> +		return NULL;
> +
> +	desc = kzalloc(NVDIMM_KEY_DESC_LEN, GFP_KERNEL);
> +	if (!desc)
> +		return NULL;
> +
> +	keyref = keyring_search(make_key_ref(nvdimm_cred->thread_keyring, 1),
> +			&nvdimm_key_type, nvdimm->dimm_id);
> +	if (IS_ERR(keyref))
> +		key = NULL;
> +	else
> +		key = key_ref_to_ptr(keyref);
> +
> +	kfree(desc);
> +	return key;
> +}

'desc' is allocated and never used.

And with that removed, NVDIMM_KEY_DESC_LEN isn't actually used either.

- Eric