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Commit 03b65b22 authored by Dave Jiang's avatar Dave Jiang Committed by Dan Williams
Browse files

acpi/nfit, libnvdimm: Add disable passphrase support to Intel nvdimm. 



Add support to disable passphrase (security) for the Intel nvdimm. The
passphrase used for disabling is pulled from an encrypted-key in the kernel
user keyring. The action is triggered by writing "disable <keyid>" to the
sysfs attribute "security".

Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 4c6926a2

drivers/acpi/nfit/intel.c

+41 −0
Original line number Diff line number Diff line
@@ -163,6 +163,46 @@ static int intel_security_unlock(struct nvdimm *nvdimm, 
	return 0;

}



static int intel_security_disable(struct nvdimm *nvdimm,

		const struct nvdimm_key_data *key_data)

{

	int rc;

	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

	struct {

		struct nd_cmd_pkg pkg;

		struct nd_intel_disable_passphrase cmd;

	} nd_cmd = {

		.pkg = {

			.nd_command = NVDIMM_INTEL_DISABLE_PASSPHRASE,

			.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,

		},

	};



	if (!test_bit(NVDIMM_INTEL_DISABLE_PASSPHRASE, &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;

	case ND_INTEL_STATUS_INVALID_STATE:

	default:

		return -ENXIO;

	}



	return 0;

}



/*

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

 * NVDIMM_FAMILY_INTEL command support arrives on another arch.
@@ -183,6 +223,7 @@ static const struct nvdimm_security_ops __intel_security_ops = { 
	.state = intel_security_state,

	.freeze = intel_security_freeze,

	.change_key = intel_security_change_key,

	.disable = intel_security_disable,

#ifdef CONFIG_X86

	.unlock = intel_security_unlock,

#endif

drivers/nvdimm/dimm_devs.c

+44 −3
Original line number Diff line number Diff line
@@ -391,24 +391,65 @@ static ssize_t security_show(struct device *dev, 
	return -ENOTTY;

}



#define OPS						\

	C( OP_FREEZE,        "freeze",        1),	\

	C( OP_DISABLE,       "disable",       2)

#undef C

#define C(a, b, c) a

enum nvdimmsec_op_ids { OPS };

#undef C

#define C(a, b, c) { b, c }

static struct {

	const char *name;

	int args;

} ops[] = { OPS };

#undef C



#define SEC_CMD_SIZE 32

#define KEY_ID_SIZE 10



static ssize_t __security_store(struct device *dev, const char *buf, size_t len)

{

	struct nvdimm *nvdimm = to_nvdimm(dev);

	ssize_t rc;

	char cmd[SEC_CMD_SIZE+1], keystr[KEY_ID_SIZE+1],

		nkeystr[KEY_ID_SIZE+1];

	unsigned int key, newkey;

	int i;



	if (atomic_read(&nvdimm->busy))

		return -EBUSY;



	if (sysfs_streq(buf, "freeze")) {

	rc = sscanf(buf, "%"__stringify(SEC_CMD_SIZE)"s"

			" %"__stringify(KEY_ID_SIZE)"s"

			" %"__stringify(KEY_ID_SIZE)"s",

			cmd, keystr, nkeystr);

	if (rc < 1)

		return -EINVAL;

	for (i = 0; i < ARRAY_SIZE(ops); i++)

		if (sysfs_streq(cmd, ops[i].name))

			break;

	if (i >= ARRAY_SIZE(ops))

		return -EINVAL;

	if (ops[i].args > 1)

		rc = kstrtouint(keystr, 0, &key);

	if (rc >= 0 && ops[i].args > 2)

		rc = kstrtouint(nkeystr, 0, &newkey);

	if (rc < 0)

		return rc;



	if (i == OP_FREEZE) {

		dev_dbg(dev, "freeze\n");

		rc = nvdimm_security_freeze(nvdimm);

	} else if (i == OP_DISABLE) {

		dev_dbg(dev, "disable %u\n", key);

		rc = nvdimm_security_disable(nvdimm, key);

	} else

		return -EINVAL;



	if (rc == 0)

		rc = len;

	return rc;



}



static ssize_t security_store(struct device *dev,
@@ -452,7 +493,7 @@ static umode_t nvdimm_visible(struct kobject *kobj, struct attribute *a, int n) 
	if (nvdimm->sec.state < 0)

		return 0;

	/* Are there any state mutation ops? */

	if (nvdimm->sec.ops->freeze)

	if (nvdimm->sec.ops->freeze || nvdimm->sec.ops->disable)

		return a->mode;

	return 0444;

}

drivers/nvdimm/nd-core.h

+9 −0
Original line number Diff line number Diff line
@@ -57,6 +57,15 @@ static inline enum nvdimm_security_state nvdimm_security_state( 
	return nvdimm->sec.ops->state(nvdimm);

}

int nvdimm_security_freeze(struct nvdimm *nvdimm);

#if IS_ENABLED(CONFIG_NVDIMM_KEYS)

int nvdimm_security_disable(struct nvdimm *nvdimm, unsigned int keyid);

#else

static inline int nvdimm_security_disable(struct nvdimm *nvdimm,

		unsigned int keyid)

{

	return -EOPNOTSUPP;

}

#endif



/**

 * struct blk_alloc_info - tracking info for BLK dpa scanning

drivers/nvdimm/security.c

+63 −0
Original line number Diff line number Diff line
@@ -69,6 +69,36 @@ static struct key *nvdimm_request_key(struct nvdimm *nvdimm) 
	return key;

}



static struct key *nvdimm_lookup_user_key(struct nvdimm *nvdimm,

		key_serial_t id)

{

	key_ref_t keyref;

	struct key *key;

	struct encrypted_key_payload *epayload;

	struct device *dev = &nvdimm->dev;



	keyref = lookup_user_key(id, 0, 0);

	if (IS_ERR(keyref))

		return NULL;



	key = key_ref_to_ptr(keyref);

	if (key->type != &key_type_encrypted) {

		key_put(key);

		return NULL;

	}

	dev_dbg(dev, "%s: key found: %#x\n", __func__, key_serial(key));





	down_read(&key->sem);

	epayload = dereference_key_locked(key);

	if (epayload->decrypted_datalen != NVDIMM_PASSPHRASE_LEN) {

		up_read(&key->sem);

		key_put(key);

		key = NULL;

	}

	return key;

}



static struct key *nvdimm_key_revalidate(struct nvdimm *nvdimm)

{

	struct key *key;
@@ -146,3 +176,36 @@ int nvdimm_security_unlock(struct device *dev) 
	nvdimm_bus_unlock(dev);

	return rc;

}



int nvdimm_security_disable(struct nvdimm *nvdimm, unsigned int keyid)

{

	struct device *dev = &nvdimm->dev;

	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);

	struct key *key;

	int rc;



	/* The bus lock should be held at the top level of the call stack */

	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);



	if (!nvdimm->sec.ops || !nvdimm->sec.ops->disable

			|| nvdimm->sec.state < 0)

		return -EOPNOTSUPP;



	if (nvdimm->sec.state >= NVDIMM_SECURITY_FROZEN) {

		dev_warn(dev, "Incorrect security state: %d\n",

				nvdimm->sec.state);

		return -EIO;

	}



	key = nvdimm_lookup_user_key(nvdimm, keyid);

	if (!key)

		return -ENOKEY;



	rc = nvdimm->sec.ops->disable(nvdimm, key_data(key));

	dev_dbg(dev, "key: %d disable: %s\n", key_serial(key),

			rc == 0 ? "success" : "fail");



	nvdimm_put_key(key);

	nvdimm->sec.state = nvdimm_security_state(nvdimm);

	return rc;

}

include/linux/libnvdimm.h

+2 −0
Original line number Diff line number Diff line
@@ -178,6 +178,8 @@ struct nvdimm_security_ops { 
			const struct nvdimm_key_data *new_data);

	int (*unlock)(struct nvdimm *nvdimm,

			const struct nvdimm_key_data *key_data);

	int (*disable)(struct nvdimm *nvdimm,

			const struct nvdimm_key_data *key_data);

};



void badrange_init(struct badrange *badrange);