Add null-checks to prevent null pointer derefernece.

Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>

modules/cas_cache/layer_cache_management.c

@@ -1232,9 +1232,19 @@ int cache_mng_init_instance(struct ocf_mngt_cache_config *cfg,
  }
 
  if (cmd) {
- ocf_volume_t cache_obj = ocf_cache_get_volume(cache);
- struct bd_object *bd_cache_obj = bd_object(cache_obj);
- struct block_device *bdev = bd_cache_obj->btm_bd;
+ ocf_volume_t cache_obj;
+ struct bd_object *bd_cache_obj;
+ struct block_device *bdev;
+
+ cache_obj = ocf_cache_get_volume(cache);
+ if (!cache_obj) {
+ ocf_mngt_cache_unlock(cache);
+ cache_mng_exit_instance(ocf_cache_get_id(cache), false);
+ return -KCAS_ERR_NO_CACHE_ATTACHED;
+ }
+
+ bd_cache_obj = bd_object(cache_obj);
+ bdev = bd_cache_obj->btm_bd;
 
  /* If we deal with whole device, reread partitions */
  if (bdev->bd_contains == bdev)
@@ -1641,6 +1651,10 @@ int cache_mng_get_info(struct kcas_cache_info *info)
 
  if (info->info.attached) {
  uuid = ocf_cache_get_uuid(cache);
+ if (!uuid) {
+ result = -OCF_ERR_CACHE_NOT_AVAIL;
+ goto unlock;
+ }
  strlcpy(info->cache_path_name, uuid->data,
  min(sizeof(info->cache_path_name), uuid->size));
 

modules/cas_cache/volume/vol_block_dev_top.c

@@ -543,6 +543,9 @@ void _blockdev_set_exported_object_flush_fua(ocf_core_t core)
  struct request_queue *core_q, *exp_q, *cache_q;
  bool flush, fua;
 
+ if (!cache_vol)
+ return;
+
  bd_core_vol = bd_object(core_vol);
  bd_cache_vol = bd_object(cache_vol);
 
@@ -624,6 +627,9 @@ static int _blockdev_set_geometry(struct casdsk_disk *dsk, void *private)
  cache = ocf_core_get_cache(core);
  core_vol = ocf_core_get_volume(core);
  cache_vol = ocf_cache_get_volume(cache);
+ if (!cache_vol)
+ return -KCAS_ERR_NO_CACHE_ATTACHED;
+
  bd_cache_vol = bd_object(cache_vol);
  path = ocf_volume_get_uuid(core_vol)->data;