[PATCH AUTOSEL 5.18 24/47] scsi: lpfc: Resolve NULL ptr dereference after an ELS LOGO is aborted

Sasha Levin
2022-06-14T02:06:37Z

From: James Smart <jsmart2021@gmail.com>

[ Upstream commit b1b3440f437b75fb2a9b0cfe58df461e40eca474 ]

A use-after-free crash can occur after an ELS LOGO is aborted.

Specifically, a nodelist structure is freed and then
ndlp->vport->cfg_log_verbose is dereferenced in lpfc_nlp_get() when the
discovery state machine is mistakenly called a second time with
NLP_EVT_DEVICE_RM argument.

Rework lpfc_cmpl_els_logo() to prevent the duplicate calls to release a
nodelist structure.

Link: https://lore.kernel.org/r/20220603174329.63777-6-jsmart2021@gmail.com
Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@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_els.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index 892b3da1ba45..9e3899580039 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -3035,18 +3035,10 @@ lpfc_cmpl_els_logo(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
spin_unlock_irq(&ndlp->lock);
lpfc_disc_state_machine(vport, ndlp, cmdiocb,
NLP_EVT_DEVICE_RM);
- lpfc_els_free_iocb(phba, cmdiocb);
- lpfc_nlp_put(ndlp);
-
- /* Presume the node was released. */
- return;
+ goto out_rsrc_free;
}

out:
- /* Driver is done with the IO. */
- lpfc_els_free_iocb(phba, cmdiocb);
- lpfc_nlp_put(ndlp);
-
/* At this point, the LOGO processing is complete. NOTE: For a
* pt2pt topology, we are assuming the NPortID will only change
* on link up processing. For a LOGO / PLOGI initiated by the
@@ -3073,6 +3065,10 @@ lpfc_cmpl_els_logo(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
ndlp->nlp_DID, ulp_status,
ulp_word4, tmo,
vport->num_disc_nodes);
+
+ lpfc_els_free_iocb(phba, cmdiocb);
+ lpfc_nlp_put(ndlp);
+
lpfc_disc_start(vport);
return;
}
@@ -3089,6 +3085,10 @@ lpfc_cmpl_els_logo(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
lpfc_disc_state_machine(vport, ndlp, cmdiocb,
NLP_EVT_DEVICE_RM);
}
+out_rsrc_free:
+ /* Driver is done with the I/O. */
+ lpfc_els_free_iocb(phba, cmdiocb);
+ lpfc_nlp_put(ndlp);
}

/**
--
2.35.1