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Commit 4c6926a2 authored by Dave Jiang's avatar Dave Jiang Committed by Dan Williams
Browse files

acpi/nfit, libnvdimm: Add unlock of nvdimm support for Intel DIMMs 



Add support to unlock the dimm via the kernel key management APIs. The
passphrase is expected to be pulled from userspace through keyutils.
The key management and sysfs attributes are libnvdimm generic.

Encrypted keys are used to protect the nvdimm passphrase at rest. The
master key can be a trusted-key sealed in a TPM, preferred, or an
encrypted-key, more flexible, but more exposure to a potential attacker.

Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
Co-developed-by: default avatarDan Williams <dan.j.williams@intel.com>
Reported-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 37833fb7

drivers/acpi/nfit/intel.c

+109 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#include <linux/libnvdimm.h>

#include <linux/ndctl.h>

#include <linux/acpi.h>

#include <asm/smp.h>

#include "intel.h"

#include "nfit.h"
@@ -75,8 +76,116 @@ static int intel_security_freeze(struct nvdimm *nvdimm) 
	return 0;

}



static int intel_security_change_key(struct nvdimm *nvdimm,

		const struct nvdimm_key_data *old_data,

		const struct nvdimm_key_data *new_data)

{

	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

	struct {

		struct nd_cmd_pkg pkg;

		struct nd_intel_set_passphrase cmd;

	} nd_cmd = {

		.pkg = {

			.nd_command = NVDIMM_INTEL_SET_PASSPHRASE,

			.nd_family = NVDIMM_FAMILY_INTEL,

			.nd_size_in = ND_INTEL_PASSPHRASE_SIZE * 2,

			.nd_size_out = ND_INTEL_STATUS_SIZE,

			.nd_fw_size = ND_INTEL_STATUS_SIZE,

		},

	};

	int rc;



	if (!test_bit(NVDIMM_INTEL_SET_PASSPHRASE, &nfit_mem->dsm_mask))

		return -ENOTTY;



	if (old_data)

		memcpy(nd_cmd.cmd.old_pass, old_data->data,

				sizeof(nd_cmd.cmd.old_pass));

	memcpy(nd_cmd.cmd.new_pass, new_data->data,

			sizeof(nd_cmd.cmd.new_pass));

	rc = nvdimm_ctl(nvdimm, ND_CMD_CALL, &nd_cmd, sizeof(nd_cmd), NULL);

	if (rc < 0)

		return rc;



	switch (nd_cmd.cmd.status) {

	case 0:

		return 0;

	case ND_INTEL_STATUS_INVALID_PASS:

		return -EINVAL;

	case ND_INTEL_STATUS_NOT_SUPPORTED:

		return -EOPNOTSUPP;

	case ND_INTEL_STATUS_INVALID_STATE:

	default:

		return -EIO;

	}

}



static void nvdimm_invalidate_cache(void);



static int intel_security_unlock(struct nvdimm *nvdimm,

		const struct nvdimm_key_data *key_data)

{

	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

	struct {

		struct nd_cmd_pkg pkg;

		struct nd_intel_unlock_unit cmd;

	} nd_cmd = {

		.pkg = {

			.nd_command = NVDIMM_INTEL_UNLOCK_UNIT,

			.nd_family = NVDIMM_FAMILY_INTEL,

			.nd_size_in = ND_INTEL_PASSPHRASE_SIZE,

			.nd_size_out = ND_INTEL_STATUS_SIZE,

			.nd_fw_size = ND_INTEL_STATUS_SIZE,

		},

	};

	int rc;



	if (!test_bit(NVDIMM_INTEL_UNLOCK_UNIT, &nfit_mem->dsm_mask))

		return -ENOTTY;



	memcpy(nd_cmd.cmd.passphrase, key_data->data,

			sizeof(nd_cmd.cmd.passphrase));

	rc = nvdimm_ctl(nvdimm, ND_CMD_CALL, &nd_cmd, sizeof(nd_cmd), NULL);

	if (rc < 0)

		return rc;

	switch (nd_cmd.cmd.status) {

	case 0:

		break;

	case ND_INTEL_STATUS_INVALID_PASS:

		return -EINVAL;

	default:

		return -EIO;

	}



	/* DIMM unlocked, invalidate all CPU caches before we read it */

	nvdimm_invalidate_cache();



	return 0;

}



/*

 * TODO: define a cross arch wbinvd equivalent when/if

 * NVDIMM_FAMILY_INTEL command support arrives on another arch.

 */

#ifdef CONFIG_X86

static void nvdimm_invalidate_cache(void)

{

	wbinvd_on_all_cpus();

}

#else

static void nvdimm_invalidate_cache(void)

{

	WARN_ON_ONCE("cache invalidation required after unlock\n");

}

#endif



static const struct nvdimm_security_ops __intel_security_ops = {

	.state = intel_security_state,

	.freeze = intel_security_freeze,

	.change_key = intel_security_change_key,

#ifdef CONFIG_X86

	.unlock = intel_security_unlock,

#endif

};



const struct nvdimm_security_ops *intel_security_ops = &__intel_security_ops;

drivers/nvdimm/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -112,4 +112,9 @@ config OF_PMEM 


	  Select Y if unsure.



config NVDIMM_KEYS

	def_bool y

	depends on ENCRYPTED_KEYS

	depends on (LIBNVDIMM=ENCRYPTED_KEYS) || LIBNVDIMM=m



endif

drivers/nvdimm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -27,3 +27,4 @@ libnvdimm-$(CONFIG_ND_CLAIM) += claim.o 
libnvdimm-$(CONFIG_BTT) += btt_devs.o

libnvdimm-$(CONFIG_NVDIMM_PFN) += pfn_devs.o

libnvdimm-$(CONFIG_NVDIMM_DAX) += dax_devs.o

libnvdimm-$(CONFIG_NVDIMM_KEYS) += security.o

drivers/nvdimm/dimm.c

+15 −1
Original line number Diff line number Diff line
@@ -34,7 +34,11 @@ static int nvdimm_probe(struct device *dev) 
		return rc;

	}



	/* reset locked, to be validated below... */

	/*

	 * The locked status bit reflects explicit status codes from the

	 * label reading commands, revalidate it each time the driver is

	 * activated and re-reads the label area.

	 */

	nvdimm_clear_locked(dev);



	ndd = kzalloc(sizeof(*ndd), GFP_KERNEL);
@@ -51,6 +55,16 @@ static int nvdimm_probe(struct device *dev) 
	get_device(dev);

	kref_init(&ndd->kref);



	/*

	 * Attempt to unlock, if the DIMM supports security commands,

	 * otherwise the locked indication is determined by explicit

	 * status codes from the label reading commands.

	 */

	rc = nvdimm_security_unlock(dev);

	if (rc < 0)

		dev_err(dev, "failed to unlock dimm: %d\n", rc);





	/*

	 * EACCES failures reading the namespace label-area-properties

	 * are interpreted as the DIMM capacity being locked but the

drivers/nvdimm/nd.h

+8 −0
Original line number Diff line number Diff line
@@ -250,6 +250,14 @@ long nvdimm_clear_poison(struct device *dev, phys_addr_t phys, 
void nvdimm_set_aliasing(struct device *dev);

void nvdimm_set_locked(struct device *dev);

void nvdimm_clear_locked(struct device *dev);

#if IS_ENABLED(CONFIG_NVDIMM_KEYS)

int nvdimm_security_unlock(struct device *dev);

#else

static inline int nvdimm_security_unlock(struct device *dev)

{

	return 0;

}

#endif

struct nd_btt *to_nd_btt(struct device *dev);



struct nd_gen_sb {