1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2018 Intel Corporation. All rights reserved. */
4 #include <linux/module.h>
5 #include <linux/device.h>
6 #include <linux/ndctl.h>
7 #include <linux/slab.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>
18 #define NVDIMM_BASE_KEY 0
19 #define NVDIMM_NEW_KEY 1
21 static bool key_revalidate = true;
22 module_param(key_revalidate, bool, 0444);
23 MODULE_PARM_DESC(key_revalidate, "Require key validation at init.");
25 static const char zero_key[NVDIMM_PASSPHRASE_LEN];
27 static void *key_data(struct key *key)
29 struct encrypted_key_payload *epayload = dereference_key_locked(key);
31 lockdep_assert_held_read(&key->sem);
33 return epayload->decrypted_data;
36 static void nvdimm_put_key(struct key *key)
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.
50 static struct key *nvdimm_request_key(struct nvdimm *nvdimm)
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;
57 sprintf(desc, "%s%s", NVDIMM_PREFIX, nvdimm->dimm_id);
58 key = request_key(&key_type_encrypted, desc, "");
60 if (PTR_ERR(key) == -ENOKEY)
61 dev_dbg(dev, "request_key() found no key\n");
63 dev_dbg(dev, "request_key() upcall failed\n");
66 struct encrypted_key_payload *epayload;
69 epayload = dereference_key_locked(key);
70 if (epayload->decrypted_datalen != NVDIMM_PASSPHRASE_LEN) {
80 static const void *nvdimm_get_key_payload(struct nvdimm *nvdimm,
83 *key = nvdimm_request_key(nvdimm);
87 return key_data(*key);
90 static struct key *nvdimm_lookup_user_key(struct nvdimm *nvdimm,
91 key_serial_t id, int subclass)
95 struct encrypted_key_payload *epayload;
96 struct device *dev = &nvdimm->dev;
98 keyref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
102 key = key_ref_to_ptr(keyref);
103 if (key->type != &key_type_encrypted) {
108 dev_dbg(dev, "%s: key found: %#x\n", __func__, key_serial(key));
110 down_read_nested(&key->sem, subclass);
111 epayload = dereference_key_locked(key);
112 if (epayload->decrypted_datalen != NVDIMM_PASSPHRASE_LEN) {
120 static const void *nvdimm_get_user_key_payload(struct nvdimm *nvdimm,
121 key_serial_t id, int subclass, struct key **key)
125 if (subclass == NVDIMM_BASE_KEY)
131 *key = nvdimm_lookup_user_key(nvdimm, id, subclass);
135 return key_data(*key);
139 static int nvdimm_key_revalidate(struct nvdimm *nvdimm)
145 if (!nvdimm->sec.ops->change_key)
148 data = nvdimm_get_key_payload(nvdimm, &key);
151 * Send the same key to the hardware as new and old key to
152 * verify that the key is good.
154 rc = nvdimm->sec.ops->change_key(nvdimm, data, data, NVDIMM_USER);
161 nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
165 static int __nvdimm_security_unlock(struct nvdimm *nvdimm)
167 struct device *dev = &nvdimm->dev;
168 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
173 /* The bus lock should be held at the top level of the call stack */
174 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
176 if (!nvdimm->sec.ops || !nvdimm->sec.ops->unlock
177 || !nvdimm->sec.flags)
180 /* No need to go further if security is disabled */
181 if (test_bit(NVDIMM_SECURITY_DISABLED, &nvdimm->sec.flags))
184 if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
185 dev_dbg(dev, "Security operation in progress.\n");
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.
196 if (test_bit(NVDIMM_SECURITY_UNLOCKED, &nvdimm->sec.flags)) {
200 return nvdimm_key_revalidate(nvdimm);
202 data = nvdimm_get_key_payload(nvdimm, &key);
204 rc = nvdimm->sec.ops->unlock(nvdimm, data);
205 dev_dbg(dev, "key: %d unlock: %s\n", key_serial(key),
206 rc == 0 ? "success" : "fail");
209 nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
213 int nvdimm_security_unlock(struct device *dev)
215 struct nvdimm *nvdimm = to_nvdimm(dev);
218 nvdimm_bus_lock(dev);
219 rc = __nvdimm_security_unlock(nvdimm);
220 nvdimm_bus_unlock(dev);
224 static int check_security_state(struct nvdimm *nvdimm)
226 struct device *dev = &nvdimm->dev;
228 if (test_bit(NVDIMM_SECURITY_FROZEN, &nvdimm->sec.flags)) {
229 dev_dbg(dev, "Incorrect security state: %#lx\n",
234 if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
235 dev_dbg(dev, "Security operation in progress.\n");
242 static int security_disable(struct nvdimm *nvdimm, unsigned int keyid)
244 struct device *dev = &nvdimm->dev;
245 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
250 /* The bus lock should be held at the top level of the call stack */
251 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
253 if (!nvdimm->sec.ops || !nvdimm->sec.ops->disable
254 || !nvdimm->sec.flags)
257 rc = check_security_state(nvdimm);
261 data = nvdimm_get_user_key_payload(nvdimm, keyid,
262 NVDIMM_BASE_KEY, &key);
266 rc = nvdimm->sec.ops->disable(nvdimm, data);
267 dev_dbg(dev, "key: %d disable: %s\n", key_serial(key),
268 rc == 0 ? "success" : "fail");
271 nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
275 static int security_update(struct nvdimm *nvdimm, unsigned int keyid,
276 unsigned int new_keyid,
277 enum nvdimm_passphrase_type pass_type)
279 struct device *dev = &nvdimm->dev;
280 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
281 struct key *key, *newkey;
283 const void *data, *newdata;
285 /* The bus lock should be held at the top level of the call stack */
286 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
288 if (!nvdimm->sec.ops || !nvdimm->sec.ops->change_key
289 || !nvdimm->sec.flags)
292 rc = check_security_state(nvdimm);
296 data = nvdimm_get_user_key_payload(nvdimm, keyid,
297 NVDIMM_BASE_KEY, &key);
301 newdata = nvdimm_get_user_key_payload(nvdimm, new_keyid,
302 NVDIMM_NEW_KEY, &newkey);
308 rc = nvdimm->sec.ops->change_key(nvdimm, data, newdata, pass_type);
309 dev_dbg(dev, "key: %d %d update%s: %s\n",
310 key_serial(key), key_serial(newkey),
311 pass_type == NVDIMM_MASTER ? "(master)" : "(user)",
312 rc == 0 ? "success" : "fail");
314 nvdimm_put_key(newkey);
316 if (pass_type == NVDIMM_MASTER)
317 nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm,
320 nvdimm->sec.flags = nvdimm_security_flags(nvdimm,
325 static int security_erase(struct nvdimm *nvdimm, unsigned int keyid,
326 enum nvdimm_passphrase_type pass_type)
328 struct device *dev = &nvdimm->dev;
329 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
330 struct key *key = NULL;
334 /* The bus lock should be held at the top level of the call stack */
335 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
337 if (!nvdimm->sec.ops || !nvdimm->sec.ops->erase
338 || !nvdimm->sec.flags)
341 rc = check_security_state(nvdimm);
345 if (!test_bit(NVDIMM_SECURITY_UNLOCKED, &nvdimm->sec.ext_flags)
346 && pass_type == NVDIMM_MASTER) {
348 "Attempt to secure erase in wrong master state.\n");
352 data = nvdimm_get_user_key_payload(nvdimm, keyid,
353 NVDIMM_BASE_KEY, &key);
357 rc = nvdimm->sec.ops->erase(nvdimm, data, pass_type);
358 dev_dbg(dev, "key: %d erase%s: %s\n", key_serial(key),
359 pass_type == NVDIMM_MASTER ? "(master)" : "(user)",
360 rc == 0 ? "success" : "fail");
363 nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
367 static int security_overwrite(struct nvdimm *nvdimm, unsigned int keyid)
369 struct device *dev = &nvdimm->dev;
370 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
371 struct key *key = NULL;
375 /* The bus lock should be held at the top level of the call stack */
376 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
378 if (!nvdimm->sec.ops || !nvdimm->sec.ops->overwrite
379 || !nvdimm->sec.flags)
382 if (dev->driver == NULL) {
383 dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
387 rc = check_security_state(nvdimm);
391 data = nvdimm_get_user_key_payload(nvdimm, keyid,
392 NVDIMM_BASE_KEY, &key);
396 rc = nvdimm->sec.ops->overwrite(nvdimm, data);
397 dev_dbg(dev, "key: %d overwrite submission: %s\n", key_serial(key),
398 rc == 0 ? "success" : "fail");
402 set_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags);
403 set_bit(NDD_WORK_PENDING, &nvdimm->flags);
404 set_bit(NVDIMM_SECURITY_OVERWRITE, &nvdimm->sec.flags);
406 * Make sure we don't lose device while doing overwrite
410 queue_delayed_work(system_wq, &nvdimm->dwork, 0);
416 void __nvdimm_security_overwrite_query(struct nvdimm *nvdimm)
418 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev);
422 /* The bus lock should be held at the top level of the call stack */
423 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
426 * Abort and release device if we no longer have the overwrite
427 * flag set. It means the work has been canceled.
429 if (!test_bit(NDD_WORK_PENDING, &nvdimm->flags))
432 tmo = nvdimm->sec.overwrite_tmo;
434 if (!nvdimm->sec.ops || !nvdimm->sec.ops->query_overwrite
435 || !nvdimm->sec.flags)
438 rc = nvdimm->sec.ops->query_overwrite(nvdimm);
441 /* setup delayed work again */
443 queue_delayed_work(system_wq, &nvdimm->dwork, tmo * HZ);
444 nvdimm->sec.overwrite_tmo = min(15U * 60U, tmo);
449 dev_dbg(&nvdimm->dev, "overwrite failed\n");
451 dev_dbg(&nvdimm->dev, "overwrite completed\n");
454 * Mark the overwrite work done and update dimm security flags,
455 * then send a sysfs event notification to wake up userspace
456 * poll threads to picked up the changed state.
458 nvdimm->sec.overwrite_tmo = 0;
459 clear_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags);
460 clear_bit(NDD_WORK_PENDING, &nvdimm->flags);
461 nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
462 nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);
463 if (nvdimm->sec.overwrite_state)
464 sysfs_notify_dirent(nvdimm->sec.overwrite_state);
465 put_device(&nvdimm->dev);
468 void nvdimm_security_overwrite_query(struct work_struct *work)
470 struct nvdimm *nvdimm =
471 container_of(work, typeof(*nvdimm), dwork.work);
473 nvdimm_bus_lock(&nvdimm->dev);
474 __nvdimm_security_overwrite_query(nvdimm);
475 nvdimm_bus_unlock(&nvdimm->dev);
479 C( OP_FREEZE, "freeze", 1), \
480 C( OP_DISABLE, "disable", 2), \
481 C( OP_UPDATE, "update", 3), \
482 C( OP_ERASE, "erase", 2), \
483 C( OP_OVERWRITE, "overwrite", 2), \
484 C( OP_MASTER_UPDATE, "master_update", 3), \
485 C( OP_MASTER_ERASE, "master_erase", 2)
488 enum nvdimmsec_op_ids { OPS };
490 #define C(a, b, c) { b, c }
497 #define SEC_CMD_SIZE 32
498 #define KEY_ID_SIZE 10
500 ssize_t nvdimm_security_store(struct device *dev, const char *buf, size_t len)
502 struct nvdimm *nvdimm = to_nvdimm(dev);
504 char cmd[SEC_CMD_SIZE+1], keystr[KEY_ID_SIZE+1],
505 nkeystr[KEY_ID_SIZE+1];
506 unsigned int key, newkey;
509 rc = sscanf(buf, "%"__stringify(SEC_CMD_SIZE)"s"
510 " %"__stringify(KEY_ID_SIZE)"s"
511 " %"__stringify(KEY_ID_SIZE)"s",
512 cmd, keystr, nkeystr);
515 for (i = 0; i < ARRAY_SIZE(ops); i++)
516 if (sysfs_streq(cmd, ops[i].name))
518 if (i >= ARRAY_SIZE(ops))
521 rc = kstrtouint(keystr, 0, &key);
522 if (rc >= 0 && ops[i].args > 2)
523 rc = kstrtouint(nkeystr, 0, &newkey);
527 if (i == OP_FREEZE) {
528 dev_dbg(dev, "freeze\n");
529 rc = nvdimm_security_freeze(nvdimm);
530 } else if (i == OP_DISABLE) {
531 dev_dbg(dev, "disable %u\n", key);
532 rc = security_disable(nvdimm, key);
533 } else if (i == OP_UPDATE || i == OP_MASTER_UPDATE) {
534 dev_dbg(dev, "%s %u %u\n", ops[i].name, key, newkey);
535 rc = security_update(nvdimm, key, newkey, i == OP_UPDATE
536 ? NVDIMM_USER : NVDIMM_MASTER);
537 } else if (i == OP_ERASE || i == OP_MASTER_ERASE) {
538 dev_dbg(dev, "%s %u\n", ops[i].name, key);
539 if (atomic_read(&nvdimm->busy)) {
540 dev_dbg(dev, "Unable to secure erase while DIMM active.\n");
543 rc = security_erase(nvdimm, key, i == OP_ERASE
544 ? NVDIMM_USER : NVDIMM_MASTER);
545 } else if (i == OP_OVERWRITE) {
546 dev_dbg(dev, "overwrite %u\n", key);
547 if (atomic_read(&nvdimm->busy)) {
548 dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
551 rc = security_overwrite(nvdimm, key);