[PATCH AUTOSEL 4.14 001/127] scsi: lpfc: Fix kernel Oops due to null pring pointers

Sasha Levin
2019-11-22T06:19:43Z

From: James Smart <jsmart2021@gmail.com>

[ Upstream commit 5a9eeff57f340238c39c95d8e7e54c96fc722de7 ]

Driver is hitting null pring pointers in lpfc_do_work().

Pointer assignment occurs based on SLI-revision. If recovering after an
error, its possible the sli revision for the port was cleared, making the
lpfc_phba_elsring() not return a ring pointer, thus the null pointer.

Add SLI revision checking to lpfc_phba_elsring() and status checking to all
callers.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/lpfc/lpfc.h | 6 ++++++
drivers/scsi/lpfc/lpfc_els.c | 2 ++
drivers/scsi/lpfc/lpfc_init.c | 7 ++++++-
drivers/scsi/lpfc/lpfc_sli.c | 2 ++
4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
index bc61cc8bc6f02..03e95a3216c8c 100644
--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -1239,6 +1239,12 @@ lpfc_sli_read_hs(struct lpfc_hba *phba)
static inline struct lpfc_sli_ring *
lpfc_phba_elsring(struct lpfc_hba *phba)
{
+ /* Return NULL if sli_rev has become invalid due to bad fw */
+ if (phba->sli_rev != LPFC_SLI_REV4 &&
+ phba->sli_rev != LPFC_SLI_REV3 &&
+ phba->sli_rev != LPFC_SLI_REV2)
+ return NULL;
+
if (phba->sli_rev == LPFC_SLI_REV4) {
if (phba->sli4_hba.els_wq)
return phba->sli4_hba.els_wq->pring;
diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index ddd29752d96dc..0032465d1b630 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -1335,6 +1335,8 @@ lpfc_els_abort_flogi(struct lpfc_hba *phba)
Fabric_DID);

pring = lpfc_phba_elsring(phba);
+ if (unlikely(!pring))
+ return -EIO;

/*
* Check the txcmplq for an iocb that matches the nport the driver is
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 25612ccf6ff28..1da125afebddb 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -1773,7 +1773,12 @@ lpfc_sli4_port_sta_fn_reset(struct lpfc_hba *phba, int mbx_action,
lpfc_offline(phba);
/* release interrupt for possible resource change */
lpfc_sli4_disable_intr(phba);
- lpfc_sli_brdrestart(phba);
+ rc = lpfc_sli_brdrestart(phba);
+ if (rc) {
+ lpfc_printf_log(phba, KERN_ERR, LOG_INIT,
+ "6309 Failed to restart board\n");
+ return rc;
+ }
/* request and enable interrupt */
intr_mode = lpfc_sli4_enable_intr(phba, phba->intr_mode);
if (intr_mode == LPFC_INTR_ERROR) {
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 6c2b098b76095..0128ea32b208f 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -4421,6 +4421,8 @@ lpfc_sli_brdrestart_s4(struct lpfc_hba *phba)
hba_aer_enabled = phba->hba_flag & HBA_AER_ENABLED;

rc = lpfc_sli4_brdreset(phba);
+ if (rc)
+ return rc;

spin_lock_irq(&phba->hbalock);
phba->pport->stopped = 0;
--
2.20.1