[PATCH AUTOSEL 6.11 199/244] scsi: lpfc: Validate hdwq pointers before dereferencing in reset/errata paths

Sasha Levin
2024-09-25T11:50:28Z

From: Justin Tee <justin.tee@broadcom.com>

[ Upstream commit 2be1d4f11944cd6283cb97268b3e17c4424945ca ]

When the HBA is undergoing a reset or is handling an errata event, NULL ptr
dereference crashes may occur in routines such as
lpfc_sli_flush_io_rings(), lpfc_dev_loss_tmo_callbk(), or
lpfc_abort_handler().

Add NULL ptr checks before dereferencing hdwq pointers that may have been
freed due to operations colliding with a reset or errata event handler.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20240726231512.92867-4-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/lpfc/lpfc_hbadisc.c | 3 ++-
drivers/scsi/lpfc/lpfc_scsi.c | 13 +++++++++++--
drivers/scsi/lpfc/lpfc_sli.c | 11 +++++++++++
3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index 6943f6c6395c4..f21c5993e8d72 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -175,7 +175,8 @@ lpfc_dev_loss_tmo_callbk(struct fc_rport *rport)
ndlp->nlp_state, ndlp->fc4_xpt_flags);

/* Don't schedule a worker thread event if the vport is going down. */
- if (test_bit(FC_UNLOADING, &vport->load_flag)) {
+ if (test_bit(FC_UNLOADING, &vport->load_flag) ||
+ !test_bit(HBA_SETUP, &phba->hba_flag)) {
spin_lock_irqsave(&ndlp->lock, iflags);
ndlp->rport = NULL;

diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index 98ce9d97a2257..60cd60ebff38e 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -5555,11 +5555,20 @@ lpfc_abort_handler(struct scsi_cmnd *cmnd)

iocb = &lpfc_cmd->cur_iocbq;
if (phba->sli_rev == LPFC_SLI_REV4) {
- pring_s4 = phba->sli4_hba.hdwq[iocb->hba_wqidx].io_wq->pring;
- if (!pring_s4) {
+ /* if the io_wq & pring are gone, the port was reset. */
+ if (!phba->sli4_hba.hdwq[iocb->hba_wqidx].io_wq ||
+ !phba->sli4_hba.hdwq[iocb->hba_wqidx].io_wq->pring) {
+ lpfc_printf_vlog(vport, KERN_WARNING, LOG_FCP,
+ "2877 SCSI Layer I/O Abort Request "
+ "IO CMPL Status x%x ID %d LUN %llu "
+ "HBA_SETUP %d\n", FAILED,
+ cmnd->device->id,
+ (u64)cmnd->device->lun,
+ test_bit(HBA_SETUP, &phba->hba_flag));
ret = FAILED;
goto out_unlock_hba;
}
+ pring_s4 = phba->sli4_hba.hdwq[iocb->hba_wqidx].io_wq->pring;
spin_lock(&pring_s4->ring_lock);
}
/* the command is in process of being cancelled */
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 88debef2fb6db..7dc34c71eb78c 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -4687,6 +4687,17 @@ lpfc_sli_flush_io_rings(struct lpfc_hba *phba)
/* Look on all the FCP Rings for the iotag */
if (phba->sli_rev >= LPFC_SLI_REV4) {
for (i = 0; i < phba->cfg_hdw_queue; i++) {
+ if (!phba->sli4_hba.hdwq ||
+ !phba->sli4_hba.hdwq[i].io_wq) {
+ lpfc_printf_log(phba, KERN_ERR, LOG_SLI,
+ "7777 hdwq's deleted %lx "
+ "%lx %x %x\n",
+ phba->pport->load_flag,
+ phba->hba_flag,
+ phba->link_state,
+ phba->sli.sli_flag);
+ return;
+ }
pring = phba->sli4_hba.hdwq[i].io_wq->pring;

spin_lock_irq(&pring->ring_lock);
--
2.43.0