be2iscsi: Fix processing cqe for cxn whose endpoint is freed

 During heavy IO in multipath environment with many active sessions
 and port-bouncing happening, there is a race condition because of
 which beiscsi_prcess_cqe() gets called for a connection whose
 endpoint is freed.

 Checking endpoint reference for a connection before processing in
 beiscsi_process_cq().
Signed-off-by: Minh Tran <minhduc.tran@emulex.com>
Signed-off-by: John Soni Jose <sony.john-n@emulex.com>
Signed-off-by: Jayamohan Kallickal <jayamohan.kallickal@emulex.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/be2iscsi/be_main.c

@@ -2110,6 +2110,16 @@ static unsigned int beiscsi_process_cq(struct be_eq_obj *pbe_eq)
 
 		cri_index = BE_GET_CRI_FROM_CID(cid);
 		ep = phba->ep_array[cri_index];
+		if (unlikely(ep == NULL)) {
+			/* connection has already been freed
+			 * just move on to next one
+			 */
+			beiscsi_log(phba, KERN_WARNING,
+				    BEISCSI_LOG_INIT,
+				    "BM_%d : proc cqe of disconn ep: cid %d\n",
+				    cid);
+			goto proc_next_cqe;
+		}
 		beiscsi_ep = ep->dd_data;
 		beiscsi_conn = beiscsi_ep->conn;
 
@@ -2219,6 +2229,7 @@ static unsigned int beiscsi_process_cq(struct be_eq_obj *pbe_eq)
 			break;
 		}
 
+proc_next_cqe:
 		AMAP_SET_BITS(struct amap_sol_cqe, valid, sol, 0);
 		queue_tail_inc(cq);
 		sol = queue_tail_node(cq);