[linux-block.git] / drivers / nvdimm / security.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2018 Intel Corporation. All rights reserved. */

#include <linux/module.h>
#include <linux/device.h>
#include <linux/ndctl.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/cred.h>
#include <linux/key.h>
#include <linux/key-type.h>
#include <keys/user-type.h>
#include <keys/encrypted-type.h>
#include "nd-core.h"
#include "nd.h"

#define NVDIMM_BASE_KEY		0
#define NVDIMM_NEW_KEY		1

static bool key_revalidate = true;
module_param(key_revalidate, bool, 0444);
MODULE_PARM_DESC(key_revalidate, "Require key validation at init.");

static const char zero_key[NVDIMM_PASSPHRASE_LEN];

static void *key_data(struct key *key)
{
	struct encrypted_key_payload *epayload = dereference_key_locked(key);

	lockdep_assert_held_read(&key->sem);

	return epayload->decrypted_data;
}

static void nvdimm_put_key(struct key *key)
{
	if (!key)
		return;

	up_read(&key->sem);
	key_put(key);
}

/*
 * Retrieve kernel key for DIMM and request from user space if
 * necessary. Returns a key held for read and must be put by
 * nvdimm_put_key() before the usage goes out of scope.
 */
static struct key *nvdimm_request_key(struct nvdimm *nvdimm)
{
	struct key *key = NULL;
	static const char NVDIMM_PREFIX[] = "nvdimm:";
	char desc[NVDIMM_KEY_DESC_LEN + sizeof(NVDIMM_PREFIX)];
	struct device *dev = &nvdimm->dev;

	sprintf(desc, "%s%s", NVDIMM_PREFIX, nvdimm->dimm_id);
	key = request_key(&key_type_encrypted, desc, "");
	if (IS_ERR(key)) {
		if (PTR_ERR(key) == -ENOKEY)
			dev_dbg(dev, "request_key() found no key\n");
		else
			dev_dbg(dev, "request_key() upcall failed\n");
		key = NULL;
	} else {
		struct encrypted_key_payload *epayload;

		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 const void *nvdimm_get_key_payload(struct nvdimm *nvdimm,
		struct key **key)
{
	*key = nvdimm_request_key(nvdimm);
	if (!*key)
		return zero_key;

	return key_data(*key);
}

static struct key *nvdimm_lookup_user_key(struct nvdimm *nvdimm,
		key_serial_t id, int subclass)
{
	key_ref_t keyref;
	struct key *key;
	struct encrypted_key_payload *epayload;
	struct device *dev = &nvdimm->dev;

	keyref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
	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_nested(&key->sem, subclass);
	epayload = dereference_key_locked(key);
	if (epayload->decrypted_datalen != NVDIMM_PASSPHRASE_LEN) {
		up_read(&key->sem);
		key_put(key);
		key = NULL;
	}
	return key;
}

static const void *nvdimm_get_user_key_payload(struct nvdimm *nvdimm,
		key_serial_t id, int subclass, struct key **key)
{
	*key = NULL;
	if (id == 0) {
		if (subclass == NVDIMM_BASE_KEY)
			return zero_key;
		else
			return NULL;
	}

	*key = nvdimm_lookup_user_key(nvdimm, id, subclass);
	if (!*key)
		return NULL;

	return key_data(*key);
}


static int nvdimm_key_revalidate(struct nvdimm *nvdimm)
{
	struct key *key;
	int rc;
	const void *data;

	if (!nvdimm->sec.ops->change_key)
		return -EOPNOTSUPP;

	data = nvdimm_get_key_payload(nvdimm, &key);

	/*
	 * Send the same key to the hardware as new and old key to
	 * verify that the key is good.
	 */
	rc = nvdimm->sec.ops->change_key(nvdimm, data, data, NVDIMM_USER);
	if (rc < 0) {
		nvdimm_put_key(key);
		return rc;
	}

	nvdimm_put_key(key);
	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
	return 0;
}

static int __nvdimm_security_unlock(struct nvdimm *nvdimm)
{
	struct device *dev = &nvdimm->dev;
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
	struct key *key;
	const void *data;
	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->unlock
			|| !nvdimm->sec.flags)
		return -EIO;

	/* No need to go further if security is disabled */
	if (test_bit(NVDIMM_SECURITY_DISABLED, &nvdimm->sec.flags))
		return 0;

	if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
		dev_dbg(dev, "Security operation in progress.\n");
		return -EBUSY;
	}

	/*
	 * If the pre-OS has unlocked the DIMM, attempt to send the key
	 * from request_key() to the hardware for verification.  Failure
	 * to revalidate the key against the hardware results in a
	 * freeze of the security configuration. I.e. if the OS does not
	 * have the key, security is being managed pre-OS.
	 */
	if (test_bit(NVDIMM_SECURITY_UNLOCKED, &nvdimm->sec.flags)) {
		if (!key_revalidate)
			return 0;

		return nvdimm_key_revalidate(nvdimm);
	} else
		data = nvdimm_get_key_payload(nvdimm, &key);

	rc = nvdimm->sec.ops->unlock(nvdimm, data);
	dev_dbg(dev, "key: %d unlock: %s\n", key_serial(key),
			rc == 0 ? "success" : "fail");

	nvdimm_put_key(key);
	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
	return rc;
}

int nvdimm_security_unlock(struct device *dev)
{
	struct nvdimm *nvdimm = to_nvdimm(dev);
	int rc;

	nvdimm_bus_lock(dev);
	rc = __nvdimm_security_unlock(nvdimm);
	nvdimm_bus_unlock(dev);
	return rc;
}

static int check_security_state(struct nvdimm *nvdimm)
{
	struct device *dev = &nvdimm->dev;

	if (test_bit(NVDIMM_SECURITY_FROZEN, &nvdimm->sec.flags)) {
		dev_dbg(dev, "Incorrect security state: %#lx\n",
				nvdimm->sec.flags);
		return -EIO;
	}

	if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
		dev_dbg(dev, "Security operation in progress.\n");
		return -EBUSY;
	}

	return 0;
}

static int 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;
	const void *data;

	/* 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.flags)
		return -EOPNOTSUPP;

	rc = check_security_state(nvdimm);
	if (rc)
		return rc;

	data = nvdimm_get_user_key_payload(nvdimm, keyid,
			NVDIMM_BASE_KEY, &key);
	if (!data)
		return -ENOKEY;

	rc = nvdimm->sec.ops->disable(nvdimm, data);
	dev_dbg(dev, "key: %d disable: %s\n", key_serial(key),
			rc == 0 ? "success" : "fail");

	nvdimm_put_key(key);
	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
	return rc;
}

static int security_update(struct nvdimm *nvdimm, unsigned int keyid,
		unsigned int new_keyid,
		enum nvdimm_passphrase_type pass_type)
{
	struct device *dev = &nvdimm->dev;
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
	struct key *key, *newkey;
	int rc;
	const void *data, *newdata;

	/* 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->change_key
			|| !nvdimm->sec.flags)
		return -EOPNOTSUPP;

	rc = check_security_state(nvdimm);
	if (rc)
		return rc;

	data = nvdimm_get_user_key_payload(nvdimm, keyid,
			NVDIMM_BASE_KEY, &key);
	if (!data)
		return -ENOKEY;

	newdata = nvdimm_get_user_key_payload(nvdimm, new_keyid,
			NVDIMM_NEW_KEY, &newkey);
	if (!newdata) {
		nvdimm_put_key(key);
		return -ENOKEY;
	}

	rc = nvdimm->sec.ops->change_key(nvdimm, data, newdata, pass_type);
	dev_dbg(dev, "key: %d %d update%s: %s\n",
			key_serial(key), key_serial(newkey),
			pass_type == NVDIMM_MASTER ? "(master)" : "(user)",
			rc == 0 ? "success" : "fail");

	nvdimm_put_key(newkey);
	nvdimm_put_key(key);
	if (pass_type == NVDIMM_MASTER)
		nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm,
				NVDIMM_MASTER);
	else
		nvdimm->sec.flags = nvdimm_security_flags(nvdimm,
				NVDIMM_USER);
	return rc;
}

static int security_erase(struct nvdimm *nvdimm, unsigned int keyid,
		enum nvdimm_passphrase_type pass_type)
{
	struct device *dev = &nvdimm->dev;
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
	struct key *key = NULL;
	int rc;
	const void *data;

	/* 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->erase
			|| !nvdimm->sec.flags)
		return -EOPNOTSUPP;

	rc = check_security_state(nvdimm);
	if (rc)
		return rc;

	if (!test_bit(NVDIMM_SECURITY_UNLOCKED, &nvdimm->sec.ext_flags)
			&& pass_type == NVDIMM_MASTER) {
		dev_dbg(dev,
			"Attempt to secure erase in wrong master state.\n");
		return -EOPNOTSUPP;
	}

	data = nvdimm_get_user_key_payload(nvdimm, keyid,
			NVDIMM_BASE_KEY, &key);
	if (!data)
		return -ENOKEY;

	rc = nvdimm->sec.ops->erase(nvdimm, data, pass_type);
	dev_dbg(dev, "key: %d erase%s: %s\n", key_serial(key),
			pass_type == NVDIMM_MASTER ? "(master)" : "(user)",
			rc == 0 ? "success" : "fail");

	nvdimm_put_key(key);
	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
	return rc;
}

static int security_overwrite(struct nvdimm *nvdimm, unsigned int keyid)
{
	struct device *dev = &nvdimm->dev;
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
	struct key *key = NULL;
	int rc;
	const void *data;

	/* 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->overwrite
			|| !nvdimm->sec.flags)
		return -EOPNOTSUPP;

	rc = check_security_state(nvdimm);
	if (rc)
		return rc;

	data = nvdimm_get_user_key_payload(nvdimm, keyid,
			NVDIMM_BASE_KEY, &key);
	if (!data)
		return -ENOKEY;

	rc = nvdimm->sec.ops->overwrite(nvdimm, data);
	dev_dbg(dev, "key: %d overwrite submission: %s\n", key_serial(key),
			rc == 0 ? "success" : "fail");

	nvdimm_put_key(key);
	if (rc == 0) {
		set_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags);
		set_bit(NDD_WORK_PENDING, &nvdimm->flags);
		set_bit(NVDIMM_SECURITY_OVERWRITE, &nvdimm->sec.flags);
		/*
		 * Make sure we don't lose device while doing overwrite
		 * query.
		 */
		get_device(dev);
		queue_delayed_work(system_wq, &nvdimm->dwork, 0);
	}

	return rc;
}

static void __nvdimm_security_overwrite_query(struct nvdimm *nvdimm)
{
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev);
	int rc;
	unsigned int tmo;

	/* The bus lock should be held at the top level of the call stack */
	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);

	/*
	 * Abort and release device if we no longer have the overwrite
	 * flag set. It means the work has been canceled.
	 */
	if (!test_bit(NDD_WORK_PENDING, &nvdimm->flags))
		return;

	tmo = nvdimm->sec.overwrite_tmo;

	if (!nvdimm->sec.ops || !nvdimm->sec.ops->query_overwrite
			|| !nvdimm->sec.flags)
		return;

	rc = nvdimm->sec.ops->query_overwrite(nvdimm);
	if (rc == -EBUSY) {

		/* setup delayed work again */
		tmo += 10;
		queue_delayed_work(system_wq, &nvdimm->dwork, tmo * HZ);
		nvdimm->sec.overwrite_tmo = min(15U * 60U, tmo);
		return;
	}

	if (rc < 0)
		dev_dbg(&nvdimm->dev, "overwrite failed\n");
	else
		dev_dbg(&nvdimm->dev, "overwrite completed\n");

	/*
	 * Mark the overwrite work done and update dimm security flags,
	 * then send a sysfs event notification to wake up userspace
	 * poll threads to picked up the changed state.
	 */
	nvdimm->sec.overwrite_tmo = 0;
	clear_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags);
	clear_bit(NDD_WORK_PENDING, &nvdimm->flags);
	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
	nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);
	if (nvdimm->sec.overwrite_state)
		sysfs_notify_dirent(nvdimm->sec.overwrite_state);
	put_device(&nvdimm->dev);
}

void nvdimm_security_overwrite_query(struct work_struct *work)
{
	struct nvdimm *nvdimm =
		container_of(work, typeof(*nvdimm), dwork.work);

	nvdimm_bus_lock(&nvdimm->dev);
	__nvdimm_security_overwrite_query(nvdimm);
	nvdimm_bus_unlock(&nvdimm->dev);
}

#define OPS							\
	C( OP_FREEZE,		"freeze",		1),	\
	C( OP_DISABLE,		"disable",		2),	\
	C( OP_UPDATE,		"update",		3),	\
	C( OP_ERASE,		"erase",		2),	\
	C( OP_OVERWRITE,	"overwrite",		2),	\
	C( OP_MASTER_UPDATE,	"master_update",	3),	\
	C( OP_MASTER_ERASE,	"master_erase",		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

ssize_t nvdimm_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;

	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 = security_disable(nvdimm, key);
	} else if (i == OP_UPDATE || i == OP_MASTER_UPDATE) {
		dev_dbg(dev, "%s %u %u\n", ops[i].name, key, newkey);
		rc = security_update(nvdimm, key, newkey, i == OP_UPDATE
				? NVDIMM_USER : NVDIMM_MASTER);
	} else if (i == OP_ERASE || i == OP_MASTER_ERASE) {
		dev_dbg(dev, "%s %u\n", ops[i].name, key);
		if (atomic_read(&nvdimm->busy)) {
			dev_dbg(dev, "Unable to secure erase while DIMM active.\n");
			return -EBUSY;
		}
		rc = security_erase(nvdimm, key, i == OP_ERASE
				? NVDIMM_USER : NVDIMM_MASTER);
	} else if (i == OP_OVERWRITE) {
		dev_dbg(dev, "overwrite %u\n", key);
		if (atomic_read(&nvdimm->busy)) {
			dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
			return -EBUSY;
		}
		rc = security_overwrite(nvdimm, key);
	} else
		return -EINVAL;

	if (rc == 0)
		rc = len;
	return rc;
}
Commit	Line	Data
4c6926a2 DJ	1	// SPDX-License-Identifier: GPL-2.0
	2	/* Copyright(c) 2018 Intel Corporation. All rights reserved. */
	3
	4	#include <linux/module.h>
	5	#include <linux/device.h>
	6	#include <linux/ndctl.h>
	7	#include <linux/slab.h>
	8	#include <linux/io.h>
	9	#include <linux/mm.h>
	10	#include <linux/cred.h>
	11	#include <linux/key.h>
	12	#include <linux/key-type.h>
	13	#include <keys/user-type.h>
	14	#include <keys/encrypted-type.h>
	15	#include "nd-core.h"
	16	#include "nd.h"
	17
d2a4ac73 DJ	18	#define NVDIMM_BASE_KEY 0
	19	#define NVDIMM_NEW_KEY 1
	20
4c6926a2 DJ	21	static bool key_revalidate = true;
	22	module_param(key_revalidate, bool, 0444);
	23	MODULE_PARM_DESC(key_revalidate, "Require key validation at init.");
	24
037c8489 DJ	25	static const char zero_key[NVDIMM_PASSPHRASE_LEN];
037c8489 DJ	26
4c6926a2 DJ	27	static void key_data(struct key key)
	28	{
	29	struct encrypted_key_payload *epayload = dereference_key_locked(key);
	30
	31	lockdep_assert_held_read(&key->sem);
	32
	33	return epayload->decrypted_data;
	34	}
	35
	36	static void nvdimm_put_key(struct key *key)
	37	{
64e77c8c DJ	38	if (!key)
	39	return;
	40
4c6926a2 DJ	41	up_read(&key->sem);
	42	key_put(key);
	43	}
	44
	45	/*
	46	* Retrieve kernel key for DIMM and request from user space if
	47	* necessary. Returns a key held for read and must be put by
	48	* nvdimm_put_key() before the usage goes out of scope.
	49	*/
	50	static struct key nvdimm_request_key(struct nvdimm nvdimm)
	51	{
	52	struct key *key = NULL;
	53	static const char NVDIMM_PREFIX[] = "nvdimm:";
	54	char desc[NVDIMM_KEY_DESC_LEN + sizeof(NVDIMM_PREFIX)];
	55	struct device *dev = &nvdimm->dev;
	56
	57	sprintf(desc, "%s%s", NVDIMM_PREFIX, nvdimm->dimm_id);
028db3e2	58	key = request_key(&key_type_encrypted, desc, "");
4c6926a2 DJ	59	if (IS_ERR(key)) {
4c6926a2 DJ	60	if (PTR_ERR(key) == -ENOKEY)
37379cfc	61	dev_dbg(dev, "request_key() found no key\n");
4c6926a2	62	else
37379cfc	63	dev_dbg(dev, "request_key() upcall failed\n");
4c6926a2 DJ	64	key = NULL;
	65	} else {
	66	struct encrypted_key_payload *epayload;
	67
	68	down_read(&key->sem);
	69	epayload = dereference_key_locked(key);
	70	if (epayload->decrypted_datalen != NVDIMM_PASSPHRASE_LEN) {
	71	up_read(&key->sem);
	72	key_put(key);
	73	key = NULL;
	74	}
	75	}
	76
	77	return key;
	78	}
	79
d2e5b643 DJ	80	static const void nvdimm_get_key_payload(struct nvdimm nvdimm,
	81	struct key **key)
	82	{
	83	*key = nvdimm_request_key(nvdimm);
	84	if (!*key)
	85	return zero_key;
	86
	87	return key_data(*key);
	88	}
	89
03b65b22	90	static struct key nvdimm_lookup_user_key(struct nvdimm nvdimm,
d2a4ac73	91	key_serial_t id, int subclass)
03b65b22 DJ	92	{
	93	key_ref_t keyref;
	94	struct key *key;
	95	struct encrypted_key_payload *epayload;
	96	struct device *dev = &nvdimm->dev;
	97
813357fe	98	keyref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
03b65b22 DJ	99	if (IS_ERR(keyref))
	100	return NULL;
	101
	102	key = key_ref_to_ptr(keyref);
	103	if (key->type != &key_type_encrypted) {
	104	key_put(key);
	105	return NULL;
	106	}
03b65b22	107
d2a4ac73	108	dev_dbg(dev, "%s: key found: %#x\n", __func__, key_serial(key));
03b65b22	109
d2a4ac73	110	down_read_nested(&key->sem, subclass);
03b65b22 DJ	111	epayload = dereference_key_locked(key);
	112	if (epayload->decrypted_datalen != NVDIMM_PASSPHRASE_LEN) {
	113	up_read(&key->sem);
	114	key_put(key);
	115	key = NULL;
	116	}
	117	return key;
	118	}
	119
d2e5b643 DJ	120	static const void nvdimm_get_user_key_payload(struct nvdimm nvdimm,
	121	key_serial_t id, int subclass, struct key **key)
	122	{
	123	*key = NULL;
	124	if (id == 0) {
	125	if (subclass == NVDIMM_BASE_KEY)
	126	return zero_key;
	127	else
	128	return NULL;
	129	}
	130
	131	*key = nvdimm_lookup_user_key(nvdimm, id, subclass);
	132	if (!*key)
	133	return NULL;
	134
	135	return key_data(*key);
	136	}
	137
	138
	139	static int nvdimm_key_revalidate(struct nvdimm *nvdimm)
4c6926a2 DJ	140	{
	141	struct key *key;
	142	int rc;
d2e5b643	143	const void *data;
4c6926a2 DJ	144
4c6926a2 DJ	145	if (!nvdimm->sec.ops->change_key)
d2e5b643	146	return -EOPNOTSUPP;
4c6926a2	147
d2e5b643	148	data = nvdimm_get_key_payload(nvdimm, &key);
4c6926a2 DJ	149
	150	/*
	151	* Send the same key to the hardware as new and old key to
	152	* verify that the key is good.
	153	*/
d2e5b643	154	rc = nvdimm->sec.ops->change_key(nvdimm, data, data, NVDIMM_USER);
4c6926a2 DJ	155	if (rc < 0) {
4c6926a2 DJ	156	nvdimm_put_key(key);
d2e5b643	157	return rc;
4c6926a2	158	}
d2e5b643 DJ	159
d2e5b643 DJ	160	nvdimm_put_key(key);
d78c620a	161	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
d2e5b643	162	return 0;
4c6926a2 DJ	163	}
	164
	165	static int __nvdimm_security_unlock(struct nvdimm *nvdimm)
	166	{
	167	struct device *dev = &nvdimm->dev;
	168	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
d2e5b643 DJ	169	struct key *key;
d2e5b643 DJ	170	const void *data;
4c6926a2 DJ	171	int rc;
	172
	173	/* The bus lock should be held at the top level of the call stack */
	174	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
	175
	176	if (!nvdimm->sec.ops \|\| !nvdimm->sec.ops->unlock
d78c620a	177	\|\| !nvdimm->sec.flags)
4c6926a2 DJ	178	return -EIO;
4c6926a2 DJ	179
674f31a3 DJ	180	/* No need to go further if security is disabled */
	181	if (test_bit(NVDIMM_SECURITY_DISABLED, &nvdimm->sec.flags))
	182	return 0;
	183
7d988097	184	if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
37379cfc	185	dev_dbg(dev, "Security operation in progress.\n");
7d988097 DJ	186	return -EBUSY;
	187	}
	188
4c6926a2 DJ	189	/*
	190	* If the pre-OS has unlocked the DIMM, attempt to send the key
	191	* from request_key() to the hardware for verification. Failure
	192	* to revalidate the key against the hardware results in a
	193	* freeze of the security configuration. I.e. if the OS does not
	194	* have the key, security is being managed pre-OS.
	195	*/
d78c620a	196	if (test_bit(NVDIMM_SECURITY_UNLOCKED, &nvdimm->sec.flags)) {
4c6926a2 DJ	197	if (!key_revalidate)
	198	return 0;
	199
d2e5b643	200	return nvdimm_key_revalidate(nvdimm);
4c6926a2	201	} else
d2e5b643	202	data = nvdimm_get_key_payload(nvdimm, &key);
4c6926a2	203
d2e5b643	204	rc = nvdimm->sec.ops->unlock(nvdimm, data);
4c6926a2 DJ	205	dev_dbg(dev, "key: %d unlock: %s\n", key_serial(key),
	206	rc == 0 ? "success" : "fail");
	207
	208	nvdimm_put_key(key);
d78c620a	209	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
4c6926a2 DJ	210	return rc;
	211	}
	212
	213	int nvdimm_security_unlock(struct device *dev)
	214	{
	215	struct nvdimm *nvdimm = to_nvdimm(dev);
	216	int rc;
	217
	218	nvdimm_bus_lock(dev);
	219	rc = __nvdimm_security_unlock(nvdimm);
	220	nvdimm_bus_unlock(dev);
	221	return rc;
	222	}
03b65b22	223
d78c620a DW	224	static int check_security_state(struct nvdimm *nvdimm)
	225	{
	226	struct device *dev = &nvdimm->dev;
	227
	228	if (test_bit(NVDIMM_SECURITY_FROZEN, &nvdimm->sec.flags)) {
	229	dev_dbg(dev, "Incorrect security state: %#lx\n",
	230	nvdimm->sec.flags);
	231	return -EIO;
	232	}
	233
	234	if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
	235	dev_dbg(dev, "Security operation in progress.\n");
	236	return -EBUSY;
	237	}
	238
	239	return 0;
	240	}
	241
7b60422c	242	static int security_disable(struct nvdimm *nvdimm, unsigned int keyid)
03b65b22 DJ	243	{
	244	struct device *dev = &nvdimm->dev;
	245	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
	246	struct key *key;
	247	int rc;
d2e5b643	248	const void *data;
03b65b22 DJ	249
	250	/* The bus lock should be held at the top level of the call stack */
	251	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
	252
	253	if (!nvdimm->sec.ops \|\| !nvdimm->sec.ops->disable
d78c620a	254	\|\| !nvdimm->sec.flags)
03b65b22 DJ	255	return -EOPNOTSUPP;
03b65b22 DJ	256
d78c620a DW	257	rc = check_security_state(nvdimm);
	258	if (rc)
	259	return rc;
7d988097	260
d2e5b643 DJ	261	data = nvdimm_get_user_key_payload(nvdimm, keyid,
	262	NVDIMM_BASE_KEY, &key);
	263	if (!data)
03b65b22 DJ	264	return -ENOKEY;
03b65b22 DJ	265
d2e5b643	266	rc = nvdimm->sec.ops->disable(nvdimm, data);
03b65b22 DJ	267	dev_dbg(dev, "key: %d disable: %s\n", key_serial(key),
	268	rc == 0 ? "success" : "fail");
	269
	270	nvdimm_put_key(key);
d78c620a	271	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
03b65b22 DJ	272	return rc;
03b65b22 DJ	273	}
d2a4ac73	274
7b60422c	275	static int security_update(struct nvdimm *nvdimm, unsigned int keyid,
89fa9d8e DJ	276	unsigned int new_keyid,
89fa9d8e DJ	277	enum nvdimm_passphrase_type pass_type)
d2a4ac73 DJ	278	{
	279	struct device *dev = &nvdimm->dev;
	280	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
	281	struct key key, newkey;
	282	int rc;
d2e5b643	283	const void data, newdata;
d2a4ac73 DJ	284
	285	/* The bus lock should be held at the top level of the call stack */
	286	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
	287
	288	if (!nvdimm->sec.ops \|\| !nvdimm->sec.ops->change_key
d78c620a	289	\|\| !nvdimm->sec.flags)
d2a4ac73 DJ	290	return -EOPNOTSUPP;
d2a4ac73 DJ	291
d78c620a DW	292	rc = check_security_state(nvdimm);
	293	if (rc)
	294	return rc;
d2a4ac73	295
d2e5b643 DJ	296	data = nvdimm_get_user_key_payload(nvdimm, keyid,
	297	NVDIMM_BASE_KEY, &key);
	298	if (!data)
	299	return -ENOKEY;
d2a4ac73	300
d2e5b643 DJ	301	newdata = nvdimm_get_user_key_payload(nvdimm, new_keyid,
	302	NVDIMM_NEW_KEY, &newkey);
	303	if (!newdata) {
d2a4ac73 DJ	304	nvdimm_put_key(key);
	305	return -ENOKEY;
	306	}
	307
d2e5b643	308	rc = nvdimm->sec.ops->change_key(nvdimm, data, newdata, pass_type);
89fa9d8e	309	dev_dbg(dev, "key: %d %d update%s: %s\n",
d2a4ac73	310	key_serial(key), key_serial(newkey),
89fa9d8e	311	pass_type == NVDIMM_MASTER ? "(master)" : "(user)",
d2a4ac73 DJ	312	rc == 0 ? "success" : "fail");
	313
	314	nvdimm_put_key(newkey);
	315	nvdimm_put_key(key);
89fa9d8e	316	if (pass_type == NVDIMM_MASTER)
d78c620a	317	nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm,
89fa9d8e DJ	318	NVDIMM_MASTER);
89fa9d8e DJ	319	else
d78c620a	320	nvdimm->sec.flags = nvdimm_security_flags(nvdimm,
89fa9d8e	321	NVDIMM_USER);
d2a4ac73 DJ	322	return rc;
d2a4ac73 DJ	323	}
64e77c8c	324
7b60422c	325	static int security_erase(struct nvdimm *nvdimm, unsigned int keyid,
89fa9d8e	326	enum nvdimm_passphrase_type pass_type)
64e77c8c DJ	327	{
	328	struct device *dev = &nvdimm->dev;
	329	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
037c8489	330	struct key *key = NULL;
64e77c8c	331	int rc;
037c8489	332	const void *data;
64e77c8c DJ	333
	334	/* The bus lock should be held at the top level of the call stack */
	335	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
	336
	337	if (!nvdimm->sec.ops \|\| !nvdimm->sec.ops->erase
d78c620a	338	\|\| !nvdimm->sec.flags)
64e77c8c DJ	339	return -EOPNOTSUPP;
64e77c8c DJ	340
d78c620a DW	341	rc = check_security_state(nvdimm);
	342	if (rc)
	343	return rc;
7d988097	344
d78c620a	345	if (!test_bit(NVDIMM_SECURITY_UNLOCKED, &nvdimm->sec.ext_flags)
89fa9d8e	346	&& pass_type == NVDIMM_MASTER) {
37379cfc	347	dev_dbg(dev,
89fa9d8e DJ	348	"Attempt to secure erase in wrong master state.\n");
	349	return -EOPNOTSUPP;
	350	}
	351
d2e5b643 DJ	352	data = nvdimm_get_user_key_payload(nvdimm, keyid,
	353	NVDIMM_BASE_KEY, &key);
	354	if (!data)
	355	return -ENOKEY;
64e77c8c	356
037c8489	357	rc = nvdimm->sec.ops->erase(nvdimm, data, pass_type);
89fa9d8e DJ	358	dev_dbg(dev, "key: %d erase%s: %s\n", key_serial(key),
89fa9d8e DJ	359	pass_type == NVDIMM_MASTER ? "(master)" : "(user)",
64e77c8c DJ	360	rc == 0 ? "success" : "fail");
	361
	362	nvdimm_put_key(key);
d78c620a	363	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
64e77c8c DJ	364	return rc;
64e77c8c DJ	365	}
7d988097	366
7b60422c	367	static int security_overwrite(struct nvdimm *nvdimm, unsigned int keyid)
7d988097 DJ	368	{
	369	struct device *dev = &nvdimm->dev;
	370	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
d2e5b643	371	struct key *key = NULL;
7d988097	372	int rc;
d2e5b643	373	const void *data;
7d988097 DJ	374
	375	/* The bus lock should be held at the top level of the call stack */
	376	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
	377
	378	if (!nvdimm->sec.ops \|\| !nvdimm->sec.ops->overwrite
d78c620a	379	\|\| !nvdimm->sec.flags)
7d988097 DJ	380	return -EOPNOTSUPP;
7d988097 DJ	381
d78c620a DW	382	rc = check_security_state(nvdimm);
	383	if (rc)
	384	return rc;
7d988097	385
d2e5b643 DJ	386	data = nvdimm_get_user_key_payload(nvdimm, keyid,
	387	NVDIMM_BASE_KEY, &key);
	388	if (!data)
	389	return -ENOKEY;
7d988097	390
d2e5b643	391	rc = nvdimm->sec.ops->overwrite(nvdimm, data);
7d988097 DJ	392	dev_dbg(dev, "key: %d overwrite submission: %s\n", key_serial(key),
	393	rc == 0 ? "success" : "fail");
	394
	395	nvdimm_put_key(key);
	396	if (rc == 0) {
	397	set_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags);
	398	set_bit(NDD_WORK_PENDING, &nvdimm->flags);
d78c620a	399	set_bit(NVDIMM_SECURITY_OVERWRITE, &nvdimm->sec.flags);
7d988097 DJ	400	/*
	401	* Make sure we don't lose device while doing overwrite
	402	* query.
	403	*/
	404	get_device(dev);
	405	queue_delayed_work(system_wq, &nvdimm->dwork, 0);
	406	}
89fa9d8e	407
7d988097 DJ	408	return rc;
	409	}
	410
7912d30f	411	static void __nvdimm_security_overwrite_query(struct nvdimm *nvdimm)
7d988097 DJ	412	{
	413	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev);
	414	int rc;
	415	unsigned int tmo;
	416
	417	/* The bus lock should be held at the top level of the call stack */
	418	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
	419
	420	/*
	421	* Abort and release device if we no longer have the overwrite
	422	* flag set. It means the work has been canceled.
	423	*/
	424	if (!test_bit(NDD_WORK_PENDING, &nvdimm->flags))
	425	return;
	426
	427	tmo = nvdimm->sec.overwrite_tmo;
	428
	429	if (!nvdimm->sec.ops \|\| !nvdimm->sec.ops->query_overwrite
d78c620a	430	\|\| !nvdimm->sec.flags)
7d988097 DJ	431	return;
	432
	433	rc = nvdimm->sec.ops->query_overwrite(nvdimm);
	434	if (rc == -EBUSY) {
	435
	436	/* setup delayed work again */
	437	tmo += 10;
	438	queue_delayed_work(system_wq, &nvdimm->dwork, tmo * HZ);
	439	nvdimm->sec.overwrite_tmo = min(15U * 60U, tmo);
	440	return;
	441	}
	442
	443	if (rc < 0)
37379cfc	444	dev_dbg(&nvdimm->dev, "overwrite failed\n");
7d988097 DJ	445	else
	446	dev_dbg(&nvdimm->dev, "overwrite completed\n");
	447
7f674025 JC	448	/*
	449	* Mark the overwrite work done and update dimm security flags,
	450	* then send a sysfs event notification to wake up userspace
	451	* poll threads to picked up the changed state.
	452	*/
7d988097 DJ	453	nvdimm->sec.overwrite_tmo = 0;
	454	clear_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags);
	455	clear_bit(NDD_WORK_PENDING, &nvdimm->flags);
d78c620a	456	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
dad42d17	457	nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);
7f674025 JC	458	if (nvdimm->sec.overwrite_state)
	459	sysfs_notify_dirent(nvdimm->sec.overwrite_state);
	460	put_device(&nvdimm->dev);
7d988097 DJ	461	}
	462
	463	void nvdimm_security_overwrite_query(struct work_struct *work)
	464	{
	465	struct nvdimm *nvdimm =
	466	container_of(work, typeof(*nvdimm), dwork.work);
	467
	468	nvdimm_bus_lock(&nvdimm->dev);
	469	__nvdimm_security_overwrite_query(nvdimm);
	470	nvdimm_bus_unlock(&nvdimm->dev);
	471	}
7b60422c DW	472
	473	#define OPS \
	474	C( OP_FREEZE, "freeze", 1), \
	475	C( OP_DISABLE, "disable", 2), \
	476	C( OP_UPDATE, "update", 3), \
	477	C( OP_ERASE, "erase", 2), \
	478	C( OP_OVERWRITE, "overwrite", 2), \
	479	C( OP_MASTER_UPDATE, "master_update", 3), \
	480	C( OP_MASTER_ERASE, "master_erase", 2)
	481	#undef C
	482	#define C(a, b, c) a
	483	enum nvdimmsec_op_ids { OPS };
	484	#undef C
	485	#define C(a, b, c) { b, c }
	486	static struct {
	487	const char *name;
	488	int args;
	489	} ops[] = { OPS };
	490	#undef C
	491
	492	#define SEC_CMD_SIZE 32
	493	#define KEY_ID_SIZE 10
	494
	495	ssize_t nvdimm_security_store(struct device dev, const char buf, size_t len)
	496	{
	497	struct nvdimm *nvdimm = to_nvdimm(dev);
	498	ssize_t rc;
	499	char cmd[SEC_CMD_SIZE+1], keystr[KEY_ID_SIZE+1],
	500	nkeystr[KEY_ID_SIZE+1];
	501	unsigned int key, newkey;
	502	int i;
	503
	504	rc = sscanf(buf, "%"__stringify(SEC_CMD_SIZE)"s"
	505	" %"__stringify(KEY_ID_SIZE)"s"
	506	" %"__stringify(KEY_ID_SIZE)"s",
	507	cmd, keystr, nkeystr);
	508	if (rc < 1)
	509	return -EINVAL;
	510	for (i = 0; i < ARRAY_SIZE(ops); i++)
	511	if (sysfs_streq(cmd, ops[i].name))
	512	break;
	513	if (i >= ARRAY_SIZE(ops))
	514	return -EINVAL;
	515	if (ops[i].args > 1)
	516	rc = kstrtouint(keystr, 0, &key);
	517	if (rc >= 0 && ops[i].args > 2)
	518	rc = kstrtouint(nkeystr, 0, &newkey);
	519	if (rc < 0)
	520	return rc;
	521
	522	if (i == OP_FREEZE) {
	523	dev_dbg(dev, "freeze\n");
	524	rc = nvdimm_security_freeze(nvdimm);
	525	} else if (i == OP_DISABLE) {
	526	dev_dbg(dev, "disable %u\n", key);
	527	rc = security_disable(nvdimm, key);
	528	} else if (i == OP_UPDATE \|\| i == OP_MASTER_UPDATE) {
	529	dev_dbg(dev, "%s %u %u\n", ops[i].name, key, newkey);
	530	rc = security_update(nvdimm, key, newkey, i == OP_UPDATE
	531	? NVDIMM_USER : NVDIMM_MASTER);
	532	} else if (i == OP_ERASE \|\| i == OP_MASTER_ERASE) {
	533	dev_dbg(dev, "%s %u\n", ops[i].name, key);
	534	if (atomic_read(&nvdimm->busy)) {
	535	dev_dbg(dev, "Unable to secure erase while DIMM active.\n");
536	return -EBUSY;
537	}
538	rc = security_erase(nvdimm, key, i == OP_ERASE
539	? NVDIMM_USER : NVDIMM_MASTER);
540	} else if (i == OP_OVERWRITE) {
541	dev_dbg(dev, "overwrite %u\n", key);
542	if (atomic_read(&nvdimm->busy)) {
543	dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
544	return -EBUSY;
545	}
546	rc = security_overwrite(nvdimm, key);
547	} else
548	return -EINVAL;
549
550	if (rc == 0)
551	rc = len;
552	return rc;
553	}