diff mbox series

[v13,09/17] acpi/nfit, libnvdimm: Add enable/update passphrase support for Intel nvdimms

Message ID 154455997435.26509.899289981872486244.stgit@djiang5-desk3.ch.intel.com (mailing list archive)
State Superseded
Headers show
Series Adding security support for nvdimm | expand

Commit Message

Dave Jiang Dec. 11, 2018, 8:26 p.m. UTC 
Add support for enabling and updating passphrase on the Intel nvdimms.
The passphrase is the an encrypted key in the kernel user keyring.
We trigger the update via writing "update <old_keyid> <new_keyid>" to the
sysfs attribute "security". If no <old_keyid> exists (for enabling
security) then a 0 should be used.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/dimm_devs.c |   24 ++++++++++++++----
 drivers/nvdimm/nd-core.h   |    2 ++
 drivers/nvdimm/security.c  |   58 +++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 75 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 3a5727102a30..8669000ea6a6 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -397,14 +397,15 @@  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];
-	unsigned int key;
+	char cmd[SEC_CMD_SIZE+1], keystr[KEY_ID_SIZE+1],
+		nkeystr[KEY_ID_SIZE+1];
+	unsigned int key, newkey;
 
 	if (atomic_read(&nvdimm->busy))
 		return -EBUSY;
 
-	rc = sscanf(buf, "%"__stringify(SEC_CMD_SIZE)"s %"__stringify(KEY_ID_SIZE)"s",
-			cmd, keystr);
+	rc = sscanf(buf, "%"__stringify(SEC_CMD_SIZE)"s %"__stringify(KEY_ID_SIZE)"s %"__stringify(KEY_ID_SIZE)"s",
+			cmd, keystr, nkeystr);
 	if (sysfs_streq(buf, "freeze")) {
 		dev_dbg(dev, "freeze\n");
 		rc = nvdimm_security_freeze(nvdimm);
@@ -417,6 +418,18 @@  static ssize_t __security_store(struct device *dev, const char *buf, size_t len)
 		rc = nvdimm_security_disable(nvdimm, key);
 		if (rc < 0)
 			return rc;
+	} else if (sysfs_streq(cmd, "update")) {
+		if (rc != 3)
+			return -EINVAL;
+		rc = kstrtouint(keystr, 0, &key);
+		if (rc < 0)
+			return rc;
+		rc = kstrtouint(nkeystr, 0, &newkey);
+		if (rc < 0)
+			return rc;
+		rc = nvdimm_security_update(nvdimm, key, newkey);
+		if (rc < 0)
+			return rc;
 	} else
 		return -EINVAL;
 
@@ -467,7 +480,8 @@  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 || nvdimm->sec.ops->disable)
+	if (nvdimm->sec.ops->freeze || nvdimm->sec.ops->disable
+			|| nvdimm->sec.ops->change_key)
 		return a->mode;
 	return 0444;
 }
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 93e63c12ea45..ca020793a419 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -58,6 +58,8 @@  static inline enum nvdimm_security_state nvdimm_security_state(
 }
 int nvdimm_security_freeze(struct nvdimm *nvdimm);
 int nvdimm_security_disable(struct nvdimm *nvdimm, unsigned int keyid);
+int nvdimm_security_update(struct nvdimm *nvdimm, unsigned int keyid,
+		unsigned int new_keyid);
 
 /**
  * struct blk_alloc_info - tracking info for BLK dpa scanning
diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c
index 55d8806a5040..654b64fe7e9d 100644
--- a/drivers/nvdimm/security.c
+++ b/drivers/nvdimm/security.c
@@ -15,6 +15,9 @@ 
 #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.");
@@ -70,7 +73,7 @@  static struct key *nvdimm_request_key(struct nvdimm *nvdimm)
 }
 
 static struct key *nvdimm_lookup_user_key(struct nvdimm *nvdimm,
-		key_serial_t id)
+		key_serial_t id, int subclass)
 {
 	key_ref_t keyref;
 	struct key *key;
@@ -86,10 +89,10 @@  static struct key *nvdimm_lookup_user_key(struct nvdimm *nvdimm,
 		key_put(key);
 		return NULL;
 	}
-	dev_dbg(dev, "%s: key found: %#x\n", __func__, key_serial(key));
 
+	dev_dbg(dev, "%s: key found: %#x\n", __func__, key_serial(key));
 
-	down_read(&key->sem);
+	down_read_nested(&key->sem, subclass);
 	epayload = dereference_key_locked(key);
 	if (epayload->decrypted_datalen != NVDIMM_PASSPHRASE_LEN) {
 		up_read(&key->sem);
@@ -197,7 +200,7 @@  int nvdimm_security_disable(struct nvdimm *nvdimm, unsigned int keyid)
 		return -EIO;
 	}
 
-	key = nvdimm_lookup_user_key(nvdimm, keyid);
+	key = nvdimm_lookup_user_key(nvdimm, keyid, NVDIMM_BASE_KEY);
 	if (!key)
 		return -ENOKEY;
 
@@ -209,3 +212,50 @@  int nvdimm_security_disable(struct nvdimm *nvdimm, unsigned int keyid)
 	nvdimm->sec.state = nvdimm_security_state(nvdimm);
 	return rc;
 }
+
+int nvdimm_security_update(struct nvdimm *nvdimm, unsigned int keyid,
+		unsigned int new_keyid)
+{
+	struct device *dev = &nvdimm->dev;
+	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+	struct key *key, *newkey;
+	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->change_key
+			|| nvdimm->sec.state < 0)
+		return -EIO;
+
+	if (nvdimm->sec.state >= NVDIMM_SECURITY_FROZEN) {
+		dev_warn(dev, "Incorrect security state: %d\n",
+				nvdimm->sec.state);
+		return -EIO;
+	}
+
+	if (keyid == 0)
+		key = NULL;
+	else {
+		key = nvdimm_lookup_user_key(nvdimm, keyid, NVDIMM_BASE_KEY);
+		if (!key)
+			return -ENOKEY;
+	}
+
+	newkey = nvdimm_lookup_user_key(nvdimm, new_keyid, NVDIMM_NEW_KEY);
+	if (!newkey) {
+		nvdimm_put_key(key);
+		return -ENOKEY;
+	}
+
+	rc = nvdimm->sec.ops->change_key(nvdimm, key ? key_data(key) : NULL,
+			key_data(newkey));
+	dev_dbg(dev, "key: %d %d update: %s\n",
+			key_serial(key), key_serial(newkey),
+			rc == 0 ? "success" : "fail");
+
+	nvdimm_put_key(newkey);
+	nvdimm_put_key(key);
+	nvdimm->sec.state = nvdimm_security_state(nvdimm);
+	return rc;
+}