[PATCH 3.16 090/148] scsi: lpfc: fix: Coverity: lpfc_cmpl_els_rsp(): Null pointer dereferences

[Ben Hutchings]

3.16.82-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: James Smart <jsmart2021@xxxxxxxxx>

commit 6c6d59e0fe5b86cf273d6d744a6a9768c4ecc756 upstream.

Coverity reported the following:

*** CID 101747:  Null pointer dereferences  (FORWARD_NULL)
/drivers/scsi/lpfc/lpfc_els.c: 4439 in lpfc_cmpl_els_rsp()
4433     			kfree(mp);
4434     		}
4435     		mempool_free(mbox, phba->mbox_mem_pool);
4436     	}
4437     out:
4438     	if (ndlp && NLP_CHK_NODE_ACT(ndlp)) {
vvv     CID 101747:  Null pointer dereferences  (FORWARD_NULL)
vvv     Dereferencing null pointer "shost".
4439     		spin_lock_irq(shost->host_lock);
4440     		ndlp->nlp_flag &= ~(NLP_ACC_REGLOGIN | NLP_RM_DFLT_RPI);
4441     		spin_unlock_irq(shost->host_lock);
4442
4443     		/* If the node is not being used by another discovery thread,
4444     		 * and we are sending a reject, we are done with it.

Fix by adding a check for non-null shost in line 4438.
The scenario when shost is set to null is when ndlp is null.
As such, the ndlp check present was sufficient. But better safe
than sorry so add the shost check.

Reported-by: coverity-bot <keescook+coverity-bot@xxxxxxxxxxxx>
Addresses-Coverity-ID: 101747 ("Null pointer dereferences")
Fixes: 2e0fef85e098 ("[SCSI] lpfc: NPIV: split ports")

CC: James Bottomley <James.Bottomley@xxxxxxxxxxxx>
CC: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
CC: linux-next@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20191111230401.12958-3-jsmart2021@xxxxxxxxx
Reviewed-by: Ewan D. Milne <emilne@xxxxxxxxxx>
Signed-off-by: Dick Kennedy <dick.kennedy@xxxxxxxxxxxx>
Signed-off-by: James Smart <jsmart2021@xxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/scsi/lpfc/lpfc_els.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -3861,7 +3861,7 @@ lpfc_cmpl_els_rsp(struct lpfc_hba *phba,
 		mempool_free(mbox, phba->mbox_mem_pool);
 	}
 out:
-	if (ndlp && NLP_CHK_NODE_ACT(ndlp)) {
+	if (ndlp && NLP_CHK_NODE_ACT(ndlp) && shost) {
 		spin_lock_irq(shost->host_lock);
 		ndlp->nlp_flag &= ~(NLP_ACC_REGLOGIN | NLP_RM_DFLT_RPI);
 		spin_unlock_irq(shost->host_lock);