Adding a flag for nvdimm->flags to support erase functions. While it's ok to hold the nvdimm_bus lock for secure erase due to minimal time to execute the command, overwrite requires a significantly longer time and makes this impossible. The flag will block any drivers from being loaded and DIMMs being probed.
Signed-off-by: Dave Jiang <dave.ji...@intel.com> --- drivers/nvdimm/nd.h | 1 + drivers/nvdimm/region_devs.c | 7 +++++ drivers/nvdimm/security.c | 61 ++++++++++++++++++++++++++++++++++++++---- include/linux/libnvdimm.h | 2 + 4 files changed, 65 insertions(+), 6 deletions(-) diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h index f8d8f0a2a40d..6cb1cd4a39d0 100644 --- a/drivers/nvdimm/nd.h +++ b/drivers/nvdimm/nd.h @@ -250,6 +250,7 @@ long nvdimm_clear_poison(struct device *dev, phys_addr_t phys, void nvdimm_set_aliasing(struct device *dev); void nvdimm_set_locked(struct device *dev); void nvdimm_clear_locked(struct device *dev); +int nvdimm_check_security_busy(struct nvdimm *nvdimm); struct nd_btt *to_nd_btt(struct device *dev); struct nd_gen_sb { diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index 174a418cb171..a097282b2c01 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -78,6 +78,13 @@ int nd_region_activate(struct nd_region *nd_region) for (i = 0; i < nd_region->ndr_mappings; i++) { struct nd_mapping *nd_mapping = &nd_region->mapping[i]; struct nvdimm *nvdimm = nd_mapping->nvdimm; + int rc; + + rc = nvdimm_check_security_busy(nvdimm); + if (rc) { + nvdimm_bus_unlock(&nd_region->dev); + return rc; + } /* at least one null hint slot per-dimm for the "no-hint" case */ flush_data_size += sizeof(void *); diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c index d2831e61f3d8..2a83be47798e 100644 --- a/drivers/nvdimm/security.c +++ b/drivers/nvdimm/security.c @@ -19,6 +19,27 @@ static bool no_key_self_verify; module_param(no_key_self_verify, bool, 0644); MODULE_PARM_DESC(no_key_self_verify, "Bypass security key self verify"); +/* + * Check if we are doing security wipes + */ +int nvdimm_check_security_busy(struct nvdimm *nvdimm) +{ + if (test_bit(NDD_SECURITY_BUSY, &nvdimm->flags)) + return -EBUSY; + + return 0; +} + +static inline void nvdimm_set_security_busy(struct nvdimm *nvdimm) +{ + set_bit(NDD_SECURITY_BUSY, &nvdimm->flags); +} + +static inline void nvdimm_clear_security_busy(struct nvdimm *nvdimm) +{ + clear_bit(NDD_SECURITY_BUSY, &nvdimm->flags); +} + /* * Retrieve user injected key */ @@ -85,6 +106,13 @@ int nvdimm_security_erase(struct nvdimm *nvdimm, unsigned int keyid) nvdimm_bus_lock(dev); mutex_lock(&nvdimm->sec_mutex); + rc = nvdimm_check_security_busy(nvdimm); + if (rc < 0) { + dev_warn(dev, "Security operation in progress.\n"); + goto out; + } + + nvdimm_set_security_busy(nvdimm); if (atomic_read(&nvdimm->busy)) { dev_warn(dev, "Unable to secure erase while DIMM active.\n"); rc = -EBUSY; @@ -113,6 +141,7 @@ int nvdimm_security_erase(struct nvdimm *nvdimm, unsigned int keyid) key_put(key); out: + nvdimm_clear_security_busy(nvdimm); mutex_unlock(&nvdimm->sec_mutex); nvdimm_bus_unlock(dev); nvdimm_security_get_state(nvdimm); @@ -130,15 +159,19 @@ int nvdimm_security_freeze_lock(struct nvdimm *nvdimm) return -EOPNOTSUPP; mutex_lock(&nvdimm->sec_mutex); + rc = nvdimm_check_security_busy(nvdimm); + if (rc < 0) + goto out; + rc = nvdimm->security_ops->freeze_lock(nvdimm); - if (rc < 0) { - mutex_unlock(&nvdimm->sec_mutex); - return rc; - } + if (rc < 0) + goto out; nvdimm_security_get_state(nvdimm); + +out: mutex_unlock(&nvdimm->sec_mutex); - return 0; + return rc; } int nvdimm_security_disable(struct nvdimm *nvdimm, unsigned int keyid) @@ -156,6 +189,12 @@ int nvdimm_security_disable(struct nvdimm *nvdimm, unsigned int keyid) return -EOPNOTSUPP; mutex_lock(&nvdimm->sec_mutex); + rc = nvdimm_check_security_busy(nvdimm); + if (rc < 0) { + mutex_unlock(&nvdimm->sec_mutex); + return rc; + } + /* look for a key from cached key */ key = nvdimm_lookup_user_key(dev, keyid); if (!key) { @@ -232,6 +271,12 @@ int nvdimm_security_unlock_dimm(struct nvdimm *nvdimm) return 0; mutex_lock(&nvdimm->sec_mutex); + rc = nvdimm_check_security_busy(nvdimm); + if (rc < 0) { + mutex_unlock(&nvdimm->sec_mutex); + return rc; + } + /* * If the pre-OS has unlocked the DIMM, we will attempt to send * the key from request_key() to the hardware for verification. @@ -294,7 +339,7 @@ int nvdimm_security_change_key(struct nvdimm *nvdimm, unsigned int old_keyid, unsigned int new_keyid) { int rc; - struct key *key, *old_key; + struct key *key = NULL, *old_key = NULL; void *old_data = NULL, *new_data; struct device *dev = &nvdimm->dev; struct encrypted_key_payload *epayload, *old_epayload; @@ -306,6 +351,10 @@ int nvdimm_security_change_key(struct nvdimm *nvdimm, return -EBUSY; mutex_lock(&nvdimm->sec_mutex); + rc = nvdimm_check_security_busy(nvdimm); + if (rc < 0) + goto out; + /* look for a key from cached key if exists */ old_key = nvdimm_lookup_user_key(dev, old_keyid); if (old_key) diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h index 1071fe12081b..f3941836b93d 100644 --- a/include/linux/libnvdimm.h +++ b/include/linux/libnvdimm.h @@ -38,6 +38,8 @@ enum { NDD_UNARMED = 1, /* locked memory devices should not be accessed */ NDD_LOCKED = 2, + /* memory under security wipes should not be accessed */ + NDD_SECURITY_BUSY = 3, /* need to set a limit somewhere, but yes, this is likely overkill */ ND_IOCTL_MAX_BUFLEN = SZ_4M, _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm