scsi: lpfc: Fix sg_reset on SCSI device causing kernel crash

Fix sg_reset on SCSI device causing kernel crash

Driver could reference stale node pointers in task mgmt call.
Changed to use resetting cmd and look up node pointer in task mgmt
function.
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_scsi.c

@@ -4948,26 +4948,30 @@ lpfc_check_fcp_rsp(struct lpfc_vport *vport, struct lpfc_scsi_buf *lpfc_cmd)
  *   0x2002 - Success.
  **/
 static int
-lpfc_send_taskmgmt(struct lpfc_vport *vport, struct lpfc_rport_data *rdata,
-		    unsigned  tgt_id, uint64_t lun_id,
+lpfc_send_taskmgmt(struct lpfc_vport *vport, struct scsi_cmnd *cmnd,
+		   unsigned int tgt_id, uint64_t lun_id,
 		   uint8_t task_mgmt_cmd)
 {
 	struct lpfc_hba   *phba = vport->phba;
 	struct lpfc_scsi_buf *lpfc_cmd;
 	struct lpfc_iocbq *iocbq;
 	struct lpfc_iocbq *iocbqrsp;
-	struct lpfc_nodelist *pnode = rdata->pnode;
+	struct lpfc_rport_data *rdata;
+	struct lpfc_nodelist *pnode;
 	int ret;
 	int status;
 
-	if (!pnode || !NLP_CHK_NODE_ACT(pnode))
+	rdata = lpfc_rport_data_from_scsi_device(cmnd->device);
+	if (!rdata || !rdata->pnode || !NLP_CHK_NODE_ACT(rdata->pnode))
 		return FAILED;
+	pnode = rdata->pnode;
 
-	lpfc_cmd = lpfc_get_scsi_buf(phba, rdata->pnode);
+	lpfc_cmd = lpfc_get_scsi_buf(phba, pnode);
 	if (lpfc_cmd == NULL)
 		return FAILED;
 	lpfc_cmd->timeout = phba->cfg_task_mgmt_tmo;
 	lpfc_cmd->rdata = rdata;
+	lpfc_cmd->pCmd = cmnd;
 
 	status = lpfc_scsi_prep_task_mgmt_cmd(vport, lpfc_cmd, lun_id,
 					   task_mgmt_cmd);
@@ -5174,7 +5178,7 @@ lpfc_device_reset_handler(struct scsi_cmnd *cmnd)
 	fc_host_post_vendor_event(shost, fc_get_event_number(),
 		sizeof(scsi_event), (char *)&scsi_event, LPFC_NL_VENDOR_ID);
 
-	status = lpfc_send_taskmgmt(vport, rdata, tgt_id, lun_id,
+	status = lpfc_send_taskmgmt(vport, cmnd, tgt_id, lun_id,
 						FCP_LUN_RESET);
 
 	lpfc_printf_vlog(vport, KERN_ERR, LOG_FCP,
@@ -5252,7 +5256,7 @@ lpfc_target_reset_handler(struct scsi_cmnd *cmnd)
 	fc_host_post_vendor_event(shost, fc_get_event_number(),
 		sizeof(scsi_event), (char *)&scsi_event, LPFC_NL_VENDOR_ID);
 
-	status = lpfc_send_taskmgmt(vport, rdata, tgt_id, lun_id,
+	status = lpfc_send_taskmgmt(vport, cmnd, tgt_id, lun_id,
 					FCP_TARGET_RESET);
 
 	lpfc_printf_vlog(vport, KERN_ERR, LOG_FCP,
@@ -5331,7 +5335,7 @@ lpfc_bus_reset_handler(struct scsi_cmnd *cmnd)
 		if (!match)
 			continue;
 
-		status = lpfc_send_taskmgmt(vport, ndlp->rport->dd_data,
+		status = lpfc_send_taskmgmt(vport, cmnd,
 					i, 0, FCP_TARGET_RESET);
 
 		if (status != SUCCESS) {