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>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
index 554349029628..ac54cf55998f 100644
--- a/drivers/scsi/be2iscsi/be_main.c
+++ b/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);