diff --git a/fcst/ft_sess.c b/fcst/ft_sess.c
index c0e62f1ed..f1ec05c82 100644
--- a/fcst/ft_sess.c
+++ b/fcst/ft_sess.c
@@ -564,15 +564,22 @@ int ft_tgt_enable(struct scst_tgt *tgt, bool enable)
 	int ret = 0;
 
 	mutex_lock(&ft_lport_lock);
+
 	if (enable) {
 		FT_SESS_DBG("enable tgt %s\n", tgt->tgt_name);
 		tport = scst_tgt_get_tgt_priv(tgt);
+		if (tport == NULL) {
+			ret = -E_TGT_PRIV_NOT_YET_SET;
+			goto out_unlock;
+		}
 		tport->enabled = 1;
 		tport->lport->service_params |= FCP_SPPF_TARG_FCN;
 	} else {
 		FT_SESS_DBG("disable tgt %s\n", tgt->tgt_name);
 		ft_tgt_release(tgt);
 	}
+
+out_unlock:
 	mutex_unlock(&ft_lport_lock);
 	return ret;
 }
@@ -581,6 +588,9 @@ bool ft_tgt_enabled(struct scst_tgt *tgt)
 {
 	struct ft_tport *tport;
 
+	if (tgt == NULL)
+		return false;
+
 	tport = scst_tgt_get_tgt_priv(tgt);
 	return tport->enabled;
 }
diff --git a/iscsi-scst/kernel/target.c b/iscsi-scst/kernel/target.c
index fdac0b7b6..a7abc6f02 100644
--- a/iscsi-scst/kernel/target.c
+++ b/iscsi-scst/kernel/target.c
@@ -454,19 +454,22 @@ const struct seq_operations iscsi_seq_op = {
 static ssize_t iscsi_tgt_tid_show(struct kobject *kobj,
 	struct kobj_attribute *attr, char *buf)
 {
-	int pos;
+	int res = -E_TGT_PRIV_NOT_YET_SET;
 	struct scst_tgt *scst_tgt;
 	struct iscsi_target *tgt;
 
 	TRACE_ENTRY();
 
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
-	tgt = (struct iscsi_target *)scst_tgt_get_tgt_priv(scst_tgt);
+	tgt = scst_tgt_get_tgt_priv(scst_tgt);
+	if (!tgt)
+		goto out;
 
-	pos = sprintf(buf, "%u\n", tgt->tid);
+	res = sprintf(buf, "%u\n", tgt->tid);
 
-	TRACE_EXIT_RES(pos);
-	return pos;
+out:
+	TRACE_EXIT_RES(res);
+	return res;
 }
 
 static struct kobj_attribute iscsi_tgt_attr_tid =
@@ -532,6 +535,11 @@ int iscsi_enable_target(struct scst_tgt *scst_tgt, bool enable)
 
 	TRACE_ENTRY();
 
+	if (tgt == NULL) {
+		res = -E_TGT_PRIV_NOT_YET_SET;
+		goto out;
+	}
+
 	if (enable)
 		type = E_ENABLE_TARGET;
 	else
@@ -541,6 +549,7 @@ int iscsi_enable_target(struct scst_tgt *scst_tgt, bool enable)
 
 	res = iscsi_sysfs_send_event(tgt->tid, type, NULL, NULL, NULL);
 
+out:
 	TRACE_EXIT_RES(res);
 	return res;
 }
@@ -550,7 +559,10 @@ bool iscsi_is_target_enabled(struct scst_tgt *scst_tgt)
 	struct iscsi_target *tgt =
 		(struct iscsi_target *)scst_tgt_get_tgt_priv(scst_tgt);
 
-	return tgt->tgt_enabled;
+	if (tgt != NULL)
+		return tgt->tgt_enabled;
+	else
+		return false;
 }
 
 ssize_t iscsi_sysfs_add_target(const char *target_name, char *params)
diff --git a/qla2x00t/qla2x00-target/qla2x00t.c b/qla2x00t/qla2x00-target/qla2x00t.c
index 33a498635..a239c0f4e 100644
--- a/qla2x00t/qla2x00-target/qla2x00t.c
+++ b/qla2x00t/qla2x00-target/qla2x00t.c
@@ -5969,23 +5969,31 @@ out:
 static int q2t_enable_tgt(struct scst_tgt *scst_tgt, bool enable)
 {
 	struct q2t_tgt *tgt = (struct q2t_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
-	scsi_qla_host_t *ha = tgt->ha;
-	int res;
+	scsi_qla_host_t *ha;
+	int res = -E_TGT_PRIV_NOT_YET_SET;
+
+	if (tgt == NULL)
+		goto out;
+
+	ha = tgt->ha;
 
 	if (enable)
 		res = q2t_host_action(ha, ENABLE_TARGET_MODE);
 	else
 		res = q2t_host_action(ha, DISABLE_TARGET_MODE);
 
+out:
 	return res;
 }
 
 static bool q2t_is_tgt_enabled(struct scst_tgt *scst_tgt)
 {
 	struct q2t_tgt *tgt = (struct q2t_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
-	scsi_qla_host_t *ha = tgt->ha;
 
-	return qla_tgt_mode_enabled(ha);
+	if (tgt == NULL)
+		return false;
+
+	return qla_tgt_mode_enabled(tgt->ha);
 }
 
 #if ((LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 28)) || \
@@ -6193,16 +6201,19 @@ static ssize_t q2t_show_expl_conf_enabled(struct kobject *kobj,
 	struct scst_tgt *scst_tgt;
 	struct q2t_tgt *tgt;
 	scsi_qla_host_t *ha;
-	ssize_t size;
+	int res = -E_TGT_PRIV_NOT_YET_SET;
 
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
-	tgt = (struct q2t_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
+	tgt = scst_tgt_get_tgt_priv(scst_tgt);
+	if (!tgt)
+		goto out;
 	ha = tgt->ha;
 
-	size = scnprintf(buffer, PAGE_SIZE, "%d\n%s", ha->enable_explicit_conf,
+	res = scnprintf(buffer, PAGE_SIZE, "%d\n%s", ha->enable_explicit_conf,
 		ha->enable_explicit_conf ? SCST_SYSFS_KEY_MARK "\n" : "");
 
-	return size;
+out:
+	return res;
 }
 
 static ssize_t q2t_store_expl_conf_enabled(struct kobject *kobj,
@@ -6211,10 +6222,13 @@ static ssize_t q2t_store_expl_conf_enabled(struct kobject *kobj,
 	struct scst_tgt *scst_tgt;
 	struct q2t_tgt *tgt;
 	scsi_qla_host_t *ha, *pha;
+	int res = -E_TGT_PRIV_NOT_YET_SET;
 	unsigned long flags;
 
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
-	tgt = (struct q2t_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
+	tgt = scst_tgt_get_tgt_priv(scst_tgt);
+	if (!tgt)
+		goto out;
 	ha = tgt->ha;
 	pha = to_qla_parent(ha);
 
@@ -6239,7 +6253,10 @@ static ssize_t q2t_store_expl_conf_enabled(struct kobject *kobj,
 
 	spin_unlock_irqrestore(&pha->hardware_lock, flags);
 
-	return size;
+	res = size;
+
+out:
+	return res;
 }
 
 static ssize_t q2t_abort_isp_store(struct kobject *kobj,
@@ -6248,9 +6265,12 @@ static ssize_t q2t_abort_isp_store(struct kobject *kobj,
 	struct scst_tgt *scst_tgt;
 	struct q2t_tgt *tgt;
 	scsi_qla_host_t *ha;
+	int res = -E_TGT_PRIV_NOT_YET_SET;
 
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
-	tgt = (struct q2t_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
+	tgt = scst_tgt_get_tgt_priv(scst_tgt);
+	if (!tgt)
+		goto out;
 	ha = tgt->ha;
 
 	PRINT_INFO("qla2x00t(%ld): Aborting ISP", ha->instance);
@@ -6258,7 +6278,10 @@ static ssize_t q2t_abort_isp_store(struct kobject *kobj,
 	set_bit(ISP_ABORT_NEEDED, &ha->dpc_flags);
 	qla2x00_wait_for_hba_online(ha);
 
-	return size;
+	res = size;
+
+out:
+	return res;
 }
 
 static ssize_t q2t_version_show(struct kobject *kobj,
@@ -6298,12 +6321,14 @@ static ssize_t q2t_node_name_show(struct kobject *kobj,
 	struct scst_tgt *scst_tgt;
 	struct q2t_tgt *tgt;
 	scsi_qla_host_t *ha;
-	ssize_t res;
+	ssize_t res = -E_TGT_PRIV_NOT_YET_SET;
 	char *wwn;
 	uint8_t *node_name;
 
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
-	tgt = (struct q2t_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
+	tgt = scst_tgt_get_tgt_priv(scst_tgt);
+	if (!tgt)
+		goto out;
 	ha = tgt->ha;
 
 	if (ha->parent == NULL) {
@@ -6335,12 +6360,14 @@ static ssize_t q2t_node_name_store(struct kobject *kobj,
 	struct q2t_tgt *tgt;
 	scsi_qla_host_t *ha;
 	u64 node_name, old_node_name;
-	int res;
+	int res = -E_TGT_PRIV_NOT_YET_SET;
 
 	TRACE_ENTRY();
 
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
-	tgt = (struct q2t_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
+	tgt = scst_tgt_get_tgt_priv(scst_tgt);
+	if (!tgt)
+		goto out;
 	ha = tgt->ha;
 
 	sBUG_ON(ha->parent != NULL);
@@ -6387,11 +6414,13 @@ static ssize_t q2t_vp_parent_host_show(struct kobject *kobj,
 	struct scst_tgt *scst_tgt;
 	struct q2t_tgt *tgt;
 	scsi_qla_host_t *ha;
-	ssize_t res;
+	ssize_t res = -E_TGT_PRIV_NOT_YET_SET;
 	char *wwn;
 
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
-	tgt = (struct q2t_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
+	tgt = scst_tgt_get_tgt_priv(scst_tgt);
+	if (!tgt)
+		goto out;
 	ha = to_qla_parent(tgt->ha);
 
 	res = q2t_get_target_name(ha->port_name, &wwn);
diff --git a/scst/include/scst_const.h b/scst/include/scst_const.h
index 2b05b723c..f2fdc58ec 100644
--- a/scst/include/scst_const.h
+++ b/scst/include/scst_const.h
@@ -32,6 +32,10 @@
 #endif
 #include <scsi/scsi.h>
 
+#ifndef __KERNEL__
+#include <errno.h>
+#endif
+
 /*
  * Version numbers, the same as for the kernel.
  *
@@ -576,4 +580,13 @@ enum scst_tg_sup {
 #define SCST_MIN_REL_TGT_ID			1
 #define SCST_MAX_REL_TGT_ID			65535
 
+/*
+ * Error code returned by target attribute sysfs methods if invoked after
+ * scst_register_target() finished but before before scst_tgt_set_tgt_priv()
+ * has been invoked.
+ */
+enum {
+	E_TGT_PRIV_NOT_YET_SET = EBUSY
+};
+
 #endif /* __SCST_CONST_H */
diff --git a/scst_local/scst_local.c b/scst_local/scst_local.c
index f52dcd46b..9039424c9 100644
--- a/scst_local/scst_local.c
+++ b/scst_local/scst_local.c
@@ -394,6 +394,8 @@ static ssize_t scst_local_scsi_transport_version_show(struct kobject *kobj,
 	if (down_read_trylock(&scst_local_exit_rwsem) == 0)
 		goto out;
 
+	res = -E_TGT_PRIV_NOT_YET_SET;
+
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
 	tgt = scst_tgt_get_tgt_priv(scst_tgt);
 	if (!tgt)
@@ -422,6 +424,8 @@ static ssize_t scst_local_scsi_transport_version_store(struct kobject *kobj,
 	if (down_read_trylock(&scst_local_exit_rwsem) == 0)
 		goto out;
 
+	res = -E_TGT_PRIV_NOT_YET_SET;
+
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
 	tgt = scst_tgt_get_tgt_priv(scst_tgt);
 	if (!tgt)
@@ -462,6 +466,8 @@ static ssize_t scst_local_phys_transport_version_show(struct kobject *kobj,
 	if (down_read_trylock(&scst_local_exit_rwsem) == 0)
 		goto out;
 
+	res = -E_TGT_PRIV_NOT_YET_SET;
+
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
 	tgt = scst_tgt_get_tgt_priv(scst_tgt);
 	if (!tgt)
@@ -488,6 +494,8 @@ static ssize_t scst_local_phys_transport_version_store(struct kobject *kobj,
 	if (down_read_trylock(&scst_local_exit_rwsem) == 0)
 		goto out;
 
+	res = -E_TGT_PRIV_NOT_YET_SET;
+
 	scst_tgt = container_of(kobj, struct scst_tgt, tgt_kobj);
 	tgt = scst_tgt_get_tgt_priv(scst_tgt);
 	if (!tgt)
@@ -1339,9 +1347,12 @@ static void scst_local_targ_task_mgmt_done(struct scst_mgmt_cmd *mgmt_cmd)
 
 static uint16_t scst_local_get_scsi_transport_version(struct scst_tgt *scst_tgt)
 {
-	struct scst_local_tgt *tgt;
+	struct scst_local_tgt *tgt = (struct scst_local_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
 
-	tgt = (struct scst_local_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
+	/*
+	 * It's OK to not check tgt != NULL here, because new sessions
+	 * can't create before its' set.
+	 */
 
 	if (tgt->scsi_transport_version == 0)
 		return 0x0BE0; /* SAS */
@@ -1351,9 +1362,12 @@ static uint16_t scst_local_get_scsi_transport_version(struct scst_tgt *scst_tgt)
 
 static uint16_t scst_local_get_phys_transport_version(struct scst_tgt *scst_tgt)
 {
-	struct scst_local_tgt *tgt;
+	struct scst_local_tgt *tgt = (struct scst_local_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
 
-	tgt = (struct scst_local_tgt *)scst_tgt_get_tgt_priv(scst_tgt);
+	/*
+	 * It's OK to not check tgt != NULL here, because new sessions
+	 * can't create before its' set.
+	 */
 
 	return tgt->phys_transport_version;
 }
diff --git a/srpt/src/ib_srpt.c b/srpt/src/ib_srpt.c
index 0ff66d35f..105c59ad5 100644
--- a/srpt/src/ib_srpt.c
+++ b/srpt/src/ib_srpt.c
@@ -2365,12 +2365,10 @@ static struct srpt_tgt *srpt_convert_scst_tgt(struct scst_tgt *scst_tgt)
 
 	if (one_target_per_port) {
 		sport = scst_tgt_get_tgt_priv(scst_tgt);
-		BUG_ON(!sport);
-		srpt_tgt = &sport->srpt_tgt;
+		srpt_tgt = sport ? &sport->srpt_tgt : NULL;
 	} else {
 		sdev = scst_tgt_get_tgt_priv(scst_tgt);
-		BUG_ON(!sdev);
-		srpt_tgt = &sdev->srpt_tgt;
+		srpt_tgt = sdev ? &sdev->srpt_tgt : NULL;
 	}
 	return srpt_tgt;
 }
@@ -2386,7 +2384,7 @@ static int srpt_enable_target(struct scst_tgt *scst_tgt, bool enable)
 	EXTRACHECKS_WARN_ON_ONCE(irqs_disabled());
 
 	if (!srpt_tgt)
-		return -ENOENT;
+		return -E_TGT_PRIV_NOT_YET_SET;
 
 	TRACE_DBG("%s target %s", enable ? "Enabling" : "Disabling",
 		  scst_tgt->tgt_name);
@@ -2407,7 +2405,10 @@ static bool srpt_is_target_enabled(struct scst_tgt *scst_tgt)
 {
 	struct srpt_tgt *srpt_tgt = srpt_convert_scst_tgt(scst_tgt);
 
-	return srpt_tgt && srpt_tgt->enabled;
+	if (srpt_tgt)
+		return srpt_tgt->enabled;
+	else
+		return false;
 }
 #endif
 
@@ -3569,14 +3570,7 @@ static int srpt_release(struct scst_tgt *scst_tgt)
 	EXTRACHECKS_WARN_ON_ONCE(irqs_disabled());
 
 	BUG_ON(!scst_tgt);
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
-	WARN_ON(!srpt_tgt);
-	if (!srpt_tgt)
-		return -ENODEV;
-#else
-	if (WARN_ON(!srpt_tgt))
-		return -ENODEV;
-#endif
+	BUG_ON(!srpt_tgt);
 
 	srpt_release_sport(srpt_tgt);
 
@@ -3605,11 +3599,14 @@ static ssize_t show_login_info(struct kobject *kobj,
 						 tgt_kobj);
 	struct srpt_tgt *srpt_tgt = srpt_convert_scst_tgt(scst_tgt);
 	struct srpt_port *sport;
-	int i, len;
+	int i, res = -E_TGT_PRIV_NOT_YET_SET;
+
+	if (!srpt_tgt)
+		goto out;
 
 	if (one_target_per_port) {
 		sport = container_of(srpt_tgt, struct srpt_port, srpt_tgt);
-		len = sprintf(buf,
+		res = sprintf(buf,
 			      "tid_ext=%016llx,ioc_guid=%016llx,pkey=ffff,"
 			      "dgid=%04x%04x%04x%04x%04x%04x%04x%04x,"
 			      "service_id=%016llx\n",
@@ -3627,11 +3624,11 @@ static ssize_t show_login_info(struct kobject *kobj,
 		struct srpt_device *sdev;
 
 		sdev = container_of(srpt_tgt, struct srpt_device, srpt_tgt);
-		len = 0;
+		res = 0;
 		for (i = 0; i < sdev->device->phys_port_cnt; i++) {
 			sport = &sdev->port[i];
 
-			len += sprintf(buf + len,
+			res += sprintf(buf + res,
 				   "tid_ext=%016llx,ioc_guid=%016llx,pkey=ffff,"
 				   "dgid=%04x%04x%04x%04x%04x%04x%04x%04x,"
 				   "service_id=%016llx\n",
@@ -3649,7 +3646,8 @@ static ssize_t show_login_info(struct kobject *kobj,
 		}
 	}
 
-	return len;
+out:
+	return res;
 }
 
 static struct kobj_attribute srpt_show_login_info_attr =