From 03b65b22ada8115a7a7bfdf0789f6a94adfd6070 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Fri, 7 Dec 2018 10:33:30 -0700 Subject: 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 " to the sysfs attribute "security". Signed-off-by: Dave Jiang Signed-off-by: Dan Williams --- drivers/nvdimm/dimm_devs.c | 47 +++++++++++++++++++++++++++++++--- drivers/nvdimm/nd-core.h | 9 +++++++ drivers/nvdimm/security.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 116 insertions(+), 3 deletions(-) (limited to 'drivers/nvdimm') diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c index 8e0bd2ce4dd0..7f42cc4e119b 100644 --- a/drivers/nvdimm/dimm_devs.c +++ b/drivers/nvdimm/dimm_devs.c @@ -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; } diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h index 15eff40f55f6..d1351c0b1119 100644 --- a/drivers/nvdimm/nd-core.h +++ b/drivers/nvdimm/nd-core.h @@ -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 diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c index 51d77a67a9fb..647a99dd3182 100644 --- a/drivers/nvdimm/security.c +++ b/drivers/nvdimm/security.c @@ -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; +} -- cgit v1.2.3