scsi: lpfc: Fix double free in lpfc_cmpl_els_logo_acc() caused by lpfc_nlp_not_used()

Smatch detected a double free path because lpfc_nlp_not_used() releases an
ndlp object before reaching lpfc_nlp_put() at the end of
lpfc_cmpl_els_logo_acc().

Remove the outdated lpfc_nlp_not_used() routine.  In
lpfc_mbx_cmpl_ns_reg_login(), replace the call with lpfc_nlp_put().  In
lpfc_cmpl_els_logo_acc(), replace the call with lpfc_unreg_rpi() and keep
the lpfc_nlp_put() at the end of the routine.  If ndlp's rpi was
registered, then lpfc_unreg_rpi()'s completion routine performs the final
ndlp clean up after lpfc_nlp_put() is called from lpfc_cmpl_els_logo_acc().
Otherwise if ndlp has no rpi registered, the lpfc_nlp_put() at the end of
lpfc_cmpl_els_logo_acc() is the final ndlp clean up.

Fixes: 4430f7fd09ec ("scsi: lpfc: Rework locations of ndlp reference taking")
Cc: <stable@vger.kernel.org> # v5.11+
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/all/Y3OefhyyJNKH%2Fiaf@kili/
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20230417191558.83100-3-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 3 insertions, 21 deletions

diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index 5ba3a9ad9501..67bfdddb897c 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -4333,13 +4333,14 @@ out:
 
 		/* If the node is not registered with the scsi or nvme
 		 * transport, remove the fabric node.  The failed reg_login
-		 * is terminal.
+		 * is terminal and forces the removal of the last node
+		 * reference.
 		 */
 		if (!(ndlp->fc4_xpt_flags & (SCSI_XPT_REGD | NVME_XPT_REGD))) {
 			spin_lock_irq(&ndlp->lock);
 			ndlp->nlp_flag &= ~NLP_NPR_2B_DISC;
 			spin_unlock_irq(&ndlp->lock);
-			lpfc_nlp_not_used(ndlp);
+			lpfc_nlp_put(ndlp);
 		}
 
 		if (phba->fc_topology == LPFC_TOPOLOGY_LOOP) {
@@ -6704,25 +6705,6 @@ lpfc_nlp_put(struct lpfc_nodelist *ndlp)
 	return ndlp ? kref_put(&ndlp->kref, lpfc_nlp_release) : 0;
 }
 
-/* This routine free's the specified nodelist if it is not in use
- * by any other discovery thread. This routine returns 1 if the
- * ndlp has been freed. A return value of 0 indicates the ndlp is
- * not yet been released.
- */
-int
-lpfc_nlp_not_used(struct lpfc_nodelist *ndlp)
-{
-	lpfc_debugfs_disc_trc(ndlp->vport, LPFC_DISC_TRC_NODE,
-		"node not used:   did:x%x flg:x%x refcnt:x%x",
-		ndlp->nlp_DID, ndlp->nlp_flag,
-		kref_read(&ndlp->kref));
-
-	if (kref_read(&ndlp->kref) == 1)
-		if (lpfc_nlp_put(ndlp))
-			return 1;
-	return 0;
-}
-
 /**
  * lpfc_fcf_inuse - Check if FCF can be unregistered.
  * @phba: Pointer to hba context object.