scsi: lpfc: Fix system crash when port is reset.

The driver panic when using the els_wq during port reset.

Check for NULL els_wq before dereferencing.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 9 insertions, 5 deletions

diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
index 6d7840b096e6..62571fa9c6ad 100644
--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -1228,7 +1228,11 @@ lpfc_sli_read_hs(struct lpfc_hba *phba)
 static inline struct lpfc_sli_ring *
 lpfc_phba_elsring(struct lpfc_hba *phba)
 {
-        if (phba->sli_rev == LPFC_SLI_REV4)
-                return phba->sli4_hba.els_wq->pring;
+        if (phba->sli_rev == LPFC_SLI_REV4) {
+                if (phba->sli4_hba.els_wq)
+                        return phba->sli4_hba.els_wq->pring;
+                else
+                        return NULL;
+        }
         return &phba->sli.sli3_ring[LPFC_ELS_RING];
 }
diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index 0482c5580331..dcc9b3858778 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -693,9 +693,9 @@ lpfc_work_done(struct lpfc_hba *phba)
         pring = lpfc_phba_elsring(phba);
         status = (ha_copy & (HA_RXMASK  << (4*LPFC_ELS_RING)));
         status >>= (4*LPFC_ELS_RING);
-        if ((status & HA_RXMASK) ||
-            (pring->flag & LPFC_DEFERRED_RING_EVENT) ||
-            (phba->hba_flag & HBA_SP_QUEUE_EVT)) {
+        if (pring && (status & HA_RXMASK ||
+                      pring->flag & LPFC_DEFERRED_RING_EVENT ||
+                      phba->hba_flag & HBA_SP_QUEUE_EVT)) {
                 if (pring->flag & LPFC_STOP_IOCB_EVENT) {
                         pring->flag |= LPFC_DEFERRED_RING_EVENT;
                         /* Set the lpfc data pending flag */