[PATCH] scsi: lpfc: don't dereference localport before it has been null checked

From: Colin King <colin.king@canonical.com>
To: James Smart <james.smart@broadcom.com>,
	Dick Kennedy <dick.kennedy@broadcom.com>,
	"James E . J . Bottomley" <jejb@linux.vnet.ibm.com>,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	linux-scsi@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] scsi: lpfc: don't dereference localport before it has been null checked
Date: Fri, 22 Dec 2017 00:28:52 +0000	[thread overview]
Message-ID: <20171222002852.10892-1-colin.king@canonical.com> (raw)

From: Colin Ian King <colin.king@canonical.com>

localport is being dereferenced to assign lport and then immediately
afterwards localport is being sanity checked to see if it is null.
Fix this by only dereferencing localport until after it has been
null checked.

Detected by CoverityScan, CID#1463038 ("Dereference before null check")

Fixes: 3a8cefbfc5ee ("scsi: lpfc: Beef up stat counters for debug")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/scsi/lpfc/lpfc_attr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index 797bb42a6306..986a3dc2efaf 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -277,13 +277,13 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 	}
 
 	localport = vport->localport;
-	lport = (struct lpfc_nvme_lport *)localport->private;
 	if (!localport) {
 		len = snprintf(buf, PAGE_SIZE,
 				"NVME Initiator x%llx is not allocated\n",
 				wwn_to_u64(vport->fc_portname.u.wwn));
 		return len;
 	}
+	lport = (struct lpfc_nvme_lport *)localport->private;
 	len = snprintf(buf, PAGE_SIZE, "NVME Initiator Enabled\n");
 
 	spin_lock_irq(shost->host_lock);
-- 
2.14.1
