diff --git a/openair1/SCHED_NR_UE/fapi_nr_ue_l1.c b/openair1/SCHED_NR_UE/fapi_nr_ue_l1.c
index 0c992f2e3e..4e7191241c 100644
--- a/openair1/SCHED_NR_UE/fapi_nr_ue_l1.c
+++ b/openair1/SCHED_NR_UE/fapi_nr_ue_l1.c
@@ -175,6 +175,7 @@ int8_t nr_ue_scheduled_response(nr_scheduled_response_t *scheduled_response){
           pusch_config_pdu = &ul_config->ul_config_list[i].pusch_config_pdu;
           current_harq_pid = pusch_config_pdu->pusch_data.harq_process_id;
           NR_UL_UE_HARQ_t *harq_process_ul_ue = ulsch0->harq_processes[current_harq_pid];
+          harq_process_ul_ue->status = 0;
 
           if (harq_process_ul_ue){
 
diff --git a/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c b/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
index d555014bc8..50710b325f 100644
--- a/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
+++ b/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
@@ -668,7 +668,7 @@ int8_t nr_ue_process_dci(module_id_t module_id, int cc_id, uint8_t gNB_index, fr
         LOG_W(MAC, "In %s: ul_config request is NULL. Probably due to unexpected UL DCI in frame.slot %d.%d. Ignoring DCI!\n", __FUNCTION__, frame, slot);
         return -1;
       }
-
+      pthread_mutex_lock(&ul_config->mutex_ul_config);
       AssertFatal(ul_config->number_pdus<FAPI_NR_UL_CONFIG_LIST_NUM, "ul_config->number_pdus %d out of bounds\n",ul_config->number_pdus);
       nfapi_nr_ue_pusch_pdu_t *pusch_config_pdu = &ul_config->ul_config_list[ul_config->number_pdus].pusch_config_pdu;
 
@@ -676,6 +676,7 @@ int8_t nr_ue_process_dci(module_id_t module_id, int cc_id, uint8_t gNB_index, fr
 
       // Config PUSCH PDU
       ret = nr_config_pusch_pdu(mac, pusch_config_pdu, dci, NULL, rnti, &dci_format);
+      pthread_mutex_unlock(&ul_config->mutex_ul_config);
 
     }
     
@@ -729,12 +730,15 @@ int8_t nr_ue_process_dci(module_id_t module_id, int cc_id, uint8_t gNB_index, fr
         return -1;
       }
 
+      pthread_mutex_lock(&ul_config->mutex_ul_config);
+      AssertFatal(ul_config->number_pdus<FAPI_NR_UL_CONFIG_LIST_NUM, "ul_config->number_pdus %d out of bounds\n",ul_config->number_pdus);
       nfapi_nr_ue_pusch_pdu_t *pusch_config_pdu = &ul_config->ul_config_list[ul_config->number_pdus].pusch_config_pdu;
 
       fill_ul_config(ul_config, frame_tx, slot_tx, FAPI_NR_UL_CONFIG_TYPE_PUSCH);
 
       // Config PUSCH PDU
       ret = nr_config_pusch_pdu(mac, pusch_config_pdu, dci, NULL, rnti, &dci_format);
+      pthread_mutex_unlock(&ul_config->mutex_ul_config);
 
     } else AssertFatal(1==0,"Cannot schedule PUSCH\n");
     break;
@@ -3921,12 +3925,15 @@ int nr_ue_process_rar(nr_downlink_indication_t *dl_info, NR_UL_TIME_ALIGNMENT_t
         rnti = ra->t_crnti;
       }
 
+      pthread_mutex_lock(&ul_config->mutex_ul_config);
+      AssertFatal(ul_config->number_pdus<FAPI_NR_UL_CONFIG_LIST_NUM, "ul_config->number_pdus %d out of bounds\n",ul_config->number_pdus);
       nfapi_nr_ue_pusch_pdu_t *pusch_config_pdu = &ul_config->ul_config_list[ul_config->number_pdus].pusch_config_pdu;
 
       fill_ul_config(ul_config, frame_tx, slot_tx, FAPI_NR_UL_CONFIG_TYPE_PUSCH);
 
       // Config Msg3 PDU
       nr_config_pusch_pdu(mac, pusch_config_pdu, NULL, &rar_grant, rnti, NULL);
+      pthread_mutex_unlock(&ul_config->mutex_ul_config);
 
     }
 
diff --git a/openair2/LAYER2/NR_MAC_UE/nr_ue_scheduler.c b/openair2/LAYER2/NR_MAC_UE/nr_ue_scheduler.c
index 5630e09121..f6d27c54cd 100644
--- a/openair2/LAYER2/NR_MAC_UE/nr_ue_scheduler.c
+++ b/openair2/LAYER2/NR_MAC_UE/nr_ue_scheduler.c
@@ -60,12 +60,10 @@ static prach_association_pattern_t prach_assoc_pattern;
 static ssb_list_info_t ssb_list;
 
 void fill_ul_config(fapi_nr_ul_config_request_t *ul_config, frame_t frame_tx, int slot_tx, uint8_t pdu_type){
-  pthread_mutex_lock(&ul_config->mutex_ul_config);
   ul_config->ul_config_list[ul_config->number_pdus].pdu_type = pdu_type;
   ul_config->slot = slot_tx;
   ul_config->sfn = frame_tx;
   ul_config->number_pdus++;
-  pthread_mutex_unlock(&ul_config->mutex_ul_config);
 
   LOG_D(NR_MAC, "In %s: Set config request for UL transmission in [%d.%d], number of UL PDUs: %d\n", __FUNCTION__, ul_config->sfn, ul_config->slot, ul_config->number_pdus);
 
@@ -947,7 +945,10 @@ NR_UE_L2_STATE_t nr_ue_scheduler(nr_downlink_indication_t *dl_info, nr_uplink_in
 
     // Schedule ULSCH only if the current frame and slot match those in ul_config_req
     // AND if a UL grant (UL DCI or Msg3) has been received (as indicated by num_pdus)
-    if (ul_config && (ul_info->slot_tx == ul_config->slot && ul_info->frame_tx == ul_config->sfn) && ul_config->number_pdus > 0){
+    if (ul_config){
+     pthread_mutex_lock(&ul_config->mutex_ul_config);
+     if ((ul_info->slot_tx == ul_config->slot && ul_info->frame_tx == ul_config->sfn) && ul_config->number_pdus > 0){
+      pthread_mutex_unlock(&ul_config->mutex_ul_config);
 
       LOG_D(NR_MAC, "In %s:[%d.%d]: number of UL PDUs: %d with UL transmission in [%d.%d]\n", __FUNCTION__, frame_tx, slot_tx, ul_config->number_pdus, ul_config->sfn, ul_config->slot);
 
@@ -958,13 +959,14 @@ NR_UE_L2_STATE_t nr_ue_scheduler(nr_downlink_indication_t *dl_info, nr_uplink_in
       tx_req.sfn = frame_tx;
       tx_req.number_of_pdus = 0;
 
+      pthread_mutex_lock(&ul_config->mutex_ul_config);
       for (int j = 0; j < ul_config->number_pdus; j++) {
-         uint8_t *ulsch_input_buffer = &(ulsch_input_buffer_array[tx_req.number_of_pdus][MAX_ULSCH_PAYLOAD_BYTES]);
+        uint8_t *ulsch_input_buffer = &(ulsch_input_buffer_array[tx_req.number_of_pdus][MAX_ULSCH_PAYLOAD_BYTES]);
 
         fapi_nr_ul_config_request_pdu_t *ulcfg_pdu = &ul_config->ul_config_list[j];
 
         if (ulcfg_pdu->pdu_type == FAPI_NR_UL_CONFIG_TYPE_PUSCH) {
-          int mac_pdu_exist=0;
+          int mac_pdu_exist = 0;
           uint16_t TBS_bytes = ulcfg_pdu->pusch_config_pdu.pusch_data.tb_size;
           LOG_D(NR_MAC,"harq_id %d, NDI %d NDI_DCI %d, TBS_bytes %d (ra_state %d)\n",
                 ulcfg_pdu->pusch_config_pdu.pusch_data.harq_process_id,
@@ -991,7 +993,7 @@ NR_UE_L2_STATE_t nr_ue_scheduler(nr_downlink_indication_t *dl_info, nr_uplink_in
 
               // Getting IP traffic to be transmitted
               nr_ue_get_sdu(mod_id, cc_id,frame_tx, slot_tx, gNB_index, ulsch_input_buffer, TBS_bytes);
-              mac_pdu_exist=1;
+              mac_pdu_exist = 1;
             }
 
             LOG_D(NR_MAC,"Flipping NDI for harq_id %d\n",ulcfg_pdu->pusch_config_pdu.pusch_data.new_data_indicator);
@@ -1018,11 +1020,16 @@ NR_UE_L2_STATE_t nr_ue_scheduler(nr_downlink_indication_t *dl_info, nr_uplink_in
           }
         }
       }
+      pthread_mutex_unlock(&ul_config->mutex_ul_config);
 
       fill_scheduled_response(&scheduled_response, NULL, ul_config, &tx_req, mod_id, cc_id, rx_frame, rx_slot, ul_info->thread_id);
       if(mac->if_module != NULL && mac->if_module->scheduled_response != NULL){
         mac->if_module->scheduled_response(&scheduled_response);
       }
+     }
+     else {
+      pthread_mutex_unlock(&ul_config->mutex_ul_config);
+     }
     }
   }
 
@@ -2151,6 +2158,8 @@ void nr_ue_pucch_scheduler(module_id_t module_idP, frame_t frameP, int slotP, in
     pucch->resource_set_id = find_pucch_resource_set(mac, N_UCI);
     select_pucch_resource(mac, pucch);
     fapi_nr_ul_config_request_t *ul_config = get_ul_config_request(mac, slotP);
+    pthread_mutex_lock(&ul_config->mutex_ul_config);
+    AssertFatal(ul_config->number_pdus<FAPI_NR_UL_CONFIG_LIST_NUM, "ul_config->number_pdus %d out of bounds\n",ul_config->number_pdus);
     fapi_nr_ul_config_pucch_pdu *pucch_pdu = &ul_config->ul_config_list[ul_config->number_pdus].pucch_config_pdu;
     nr_ue_configure_pucch(mac,
                           slotP,
@@ -2160,6 +2169,7 @@ void nr_ue_pucch_scheduler(module_id_t module_idP, frame_t frameP, int slotP, in
                           O_SR, O_ACK, O_CSI);
     LOG_D(NR_MAC,"Configuring pucch, is_common = %d\n",pucch->is_common);
     fill_ul_config(ul_config, frameP, slotP, FAPI_NR_UL_CONFIG_TYPE_PUCCH);
+    pthread_mutex_unlock(&ul_config->mutex_ul_config);
     nr_scheduled_response_t scheduled_response;
     fill_scheduled_response(&scheduled_response, NULL, ul_config, NULL, module_idP, 0 /*TBR fix*/, frameP, slotP, thread_id);
     if(mac->if_module != NULL && mac->if_module->scheduled_response != NULL)
@@ -2220,6 +2230,8 @@ void nr_ue_prach_scheduler(module_id_t module_idP, frame_t frameP, sub_frame_t s
       format0 = format & 0xff;        // single PRACH format
       format1 = (format >> 8) & 0xff; // dual PRACH format
 
+      pthread_mutex_lock(&ul_config->mutex_ul_config);
+      AssertFatal(ul_config->number_pdus<FAPI_NR_UL_CONFIG_LIST_NUM, "ul_config->number_pdus %d out of bounds\n",ul_config->number_pdus);
       prach_config_pdu = &ul_config->ul_config_list[ul_config->number_pdus].prach_config_pdu;
       memset(prach_config_pdu, 0, sizeof(fapi_nr_ul_config_prach_pdu));
 
@@ -2302,6 +2314,7 @@ void nr_ue_prach_scheduler(module_id_t module_idP, frame_t frameP, sub_frame_t s
             AssertFatal(1 == 0, "Invalid PRACH format");
         }
       } // if format1
+      pthread_mutex_unlock(&ul_config->mutex_ul_config);
       fill_scheduled_response(&scheduled_response, NULL, ul_config, NULL, module_idP, 0 /*TBR fix*/, frameP, slotP, thread_id);
       if(mac->if_module != NULL && mac->if_module->scheduled_response != NULL)
         mac->if_module->scheduled_response(&scheduled_response);