[bug report] scsi: lpfc: Validate ELS LS_ACC completion payload

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

Hello Justin Tee,

The patch a3c3c0a806f1: "scsi: lpfc: Validate ELS LS_ACC completion
payload" from Oct 9, 2023 (linux-next), leads to the following Smatch
static checker warning:

	drivers/scsi/lpfc/lpfc_els.c:2133 lpfc_cmpl_els_plogi()
	warn: list_entry() does not return NULL 'prsp'

drivers/scsi/lpfc/lpfc_els.c
    2126                 if (release_node)
    2127                         lpfc_disc_state_machine(vport, ndlp, cmdiocb,
    2128                                                 NLP_EVT_DEVICE_RM);
    2129         } else {
    2130                 /* Good status, call state machine */
    2131                 prsp = list_entry(cmdiocb->cmd_dmabuf->list.next,
    2132                                   struct lpfc_dmabuf, list);
--> 2133                 if (!prsp)

list_entry() never returns NULL.  If the list is empty it returns an
invalid pointer.  Did you want to use list_entry_or_null()?

    2134                         goto out;
    2135                 if (!lpfc_is_els_acc_rsp(prsp))
    2136                         goto out;
    2137                 ndlp = lpfc_plogi_confirm_nport(phba, prsp->virt, ndlp);

regards,
dan carpenter