[PATCH AUTOSEL 4.9 22/42] scsi: lpfc: fix: Coverity: lpfc_cmpl_els_rsp(): Null pointer dereferences

From: Sasha Levin
Date: Wed Dec 11 2019 - 10:35:38 EST


From: James Smart <jsmart2021@xxxxxxxxx>

[ Upstream commit 6c6d59e0fe5b86cf273d6d744a6a9768c4ecc756 ]

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: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/lpfc/lpfc_els.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index 3702497b5b169..4901bf24916b5 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -3863,7 +3863,7 @@ lpfc_cmpl_els_rsp(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
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);
--
2.20.1