scsi: lpfc: Fix NULL ptr dereference with NPIV ports for RDF handling

RDF ELS handling for NPIV ports may result in an incorrect NDLP reference
count.  In the event of a persistent link down, this may lead to premature
release of an NDLP structure and subsequent NULL ptr dereference panic.

Remove extraneous lpfc_nlp_put() call in NPIV port RDF processing.

Link: https://lore.kernel.org/r/20210707184351.67872-9-jsmart2021@gmail.com
Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index b0c443a..b1ca6f8 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -3413,7 +3413,6 @@ lpfc_issue_els_scr(struct lpfc_vport *vport, uint8_t retry)
                return 1;
        }
 
-       /* Keep the ndlp just in case RDF is being sent */
        return 0;
 }
 
@@ -3657,11 +3656,9 @@ lpfc_issue_els_rdf(struct lpfc_vport *vport, uint8_t retry)
                lpfc_enqueue_node(vport, ndlp);
        }
 
-       /* RDF ELS is not required on an NPIV VN_Port.  */
-       if (vport->port_type == LPFC_NPIV_PORT) {
-               lpfc_nlp_put(ndlp);
+       /* RDF ELS is not required on an NPIV VN_Port. */
+       if (vport->port_type == LPFC_NPIV_PORT)
                return -EACCES;
-       }
 
        elsiocb = lpfc_prep_els_iocb(vport, 1, cmdsize, retry, ndlp,
                                     ndlp->nlp_DID, ELS_CMD_RDF);