Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 553 insertions, 0 deletions

diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c
new file mode 100644
index 000000000..b5aa55c61
--- /dev/null
+++ b/drivers/nvdimm/security.c
@@ -0,0 +1,553 @@
+// 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;
+}
+
+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;
+}