scsi: lpfc: Fix stale node accesses on stale RRQ request

Whenever an RRQ needs to be triggered, the DID from the node structure and
node pointer are stored in the RRQ data structure and the RRQ is scheduled
for later transmission. However, at the point in time that the timer
triggers, there's no validation on the node pointer. Reference counters may
have freed the structure. Additionally the DID in the node may no longer be
valid.

Fix by not tracking the node pointer in the RRQ, only the DID. At the time
of the timer expiration, look up the node with the did and if present, send
the RRQ. If no node exists, no need to send the RRQ.

Link: https://lore.kernel.org/r/20210301171821.3427-5-jsmart2021@gmail.com
Co-developed-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 8 insertions, 24 deletions

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index f0a758138ae8..cc0b4f2661ab 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -1849,7 +1849,7 @@ lpfc_cmpl_els_rrq(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 {
 	struct lpfc_vport *vport = cmdiocb->vport;
 	IOCB_t *irsp;
-	struct lpfc_nodelist *ndlp;
+	struct lpfc_nodelist *ndlp = cmdiocb->context1;
 	struct lpfc_node_rrq *rrq;
 
 	/* we pass cmdiocb to state machine which needs rspiocb as well */
@@ -1862,22 +1862,12 @@ lpfc_cmpl_els_rrq(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 		irsp->ulpStatus, irsp->un.ulpWord[4],
 		irsp->un.elsreq64.remoteID);
 
-	ndlp = lpfc_findnode_did(vport, irsp->un.elsreq64.remoteID);
-	if (!ndlp || ndlp != rrq->ndlp) {
-		lpfc_printf_vlog(vport, KERN_ERR, LOG_TRACE_EVENT,
-				 "2882 RRQ completes to NPort x%x "
-				 "with no ndlp. Data: x%x x%x x%x\n",
-				 irsp->un.elsreq64.remoteID,
-				 irsp->ulpStatus, irsp->un.ulpWord[4],
-				 irsp->ulpIoTag);
-		goto out;
-	}
-
 	/* rrq completes to NPort <nlp_DID> */
 	lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
-			 "2880 RRQ completes to NPort x%x "
+			 "2880 RRQ completes to DID x%x "
 			 "Data: x%x x%x x%x x%x x%x\n",
-			 ndlp->nlp_DID, irsp->ulpStatus, irsp->un.ulpWord[4],
+			 irsp->un.elsreq64.remoteID,
+			 irsp->ulpStatus, irsp->un.ulpWord[4],
 			 irsp->ulpTimeout, rrq->xritag, rrq->rxid);
 
 	if (irsp->ulpStatus) {
@@ -1893,10 +1883,8 @@ lpfc_cmpl_els_rrq(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 					 ndlp->nlp_DID, irsp->ulpStatus,
 					 irsp->un.ulpWord[4]);
 	}
-out:
-	if (rrq)
-		lpfc_clr_rrq_active(phba, rrq->xritag, rrq);
 
+	lpfc_clr_rrq_active(phba, rrq->xritag, rrq);
 	lpfc_els_free_iocb(phba, cmdiocb);
 	lpfc_nlp_put(ndlp);
 	return;
@@ -7619,9 +7607,6 @@ lpfc_issue_els_rrq(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	uint16_t cmdsize;
 	int ret;
 
-
-	if (ndlp != rrq->ndlp)
-		ndlp = rrq->ndlp;
 	if (!ndlp)
 		return 1;
 
@@ -7651,9 +7636,9 @@ lpfc_issue_els_rrq(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 		did, rrq->xritag, rrq->rxid);
 	elsiocb->context_un.rrq = rrq;
 	elsiocb->iocb_cmpl = lpfc_cmpl_els_rrq;
-	elsiocb->context1 = lpfc_nlp_get(ndlp);
-	if (!elsiocb->context1)
-		goto node_err;
+
+	lpfc_nlp_get(ndlp);
+	elsiocb->context1 = ndlp;
 
 	ret = lpfc_sli_issue_iocb(phba, LPFC_ELS_RING, elsiocb, 0);
 	if (ret == IOCB_ERROR)
@@ -7662,7 +7647,6 @@ lpfc_issue_els_rrq(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 
  io_err:
 	lpfc_nlp_put(ndlp);
- node_err:
 	lpfc_els_free_iocb(phba, elsiocb);
 	return 1;
 }