5.4-stable review patch. If anyone has any objections, please let me know.
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From: Niklas Cassel cassel@kernel.org
[ Upstream commit 251be2f6037fb7ab399f68cd7428ff274133d693 ]
Since commit f7b705c238d1 ("scsi: pm80xx: Set phy_attached to zero when device is gone") UBSAN reports:
UBSAN: array-index-out-of-bounds in drivers/scsi/pm8001/pm8001_sas.c:786:17 index 28 is out of range for type 'pm8001_phy [16]'
on rmmod when using an expander.
For a direct attached device, attached_phy contains the local phy id. For a device behind an expander, attached_phy contains the remote phy id, not the local phy id.
I.e. while pm8001_ha will have pm8001_ha->chip->n_phy local phys, for a device behind an expander, attached_phy can be much larger than pm8001_ha->chip->n_phy (depending on the amount of phys of the expander).
E.g. on my system pm8001_ha has 8 phys with phy ids 0-7. One of the ports has an expander connected. The expander has 31 phys with phy ids 0-30.
The pm8001_ha->phy array only contains the phys of the HBA. It does not contain the phys of the expander. Thus, it is wrong to use attached_phy to index the pm8001_ha->phy array for a device behind an expander.
Thus, we can only clear phy_attached for devices that are directly attached.
Fixes: f7b705c238d1 ("scsi: pm80xx: Set phy_attached to zero when device is gone") Reviewed-by: Igor Pylypiv ipylypiv@google.com Signed-off-by: Niklas Cassel cassel@kernel.org Link: https://lore.kernel.org/r/20250814173215.1765055-14-cassel@kernel.org Reviewed-by: Damien Le Moal dlemoal@kernel.org Tested-by: Damien Le Moal dlemoal@kernel.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/pm8001/pm8001_sas.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c index 1215fc36862da..45b1af5a8d748 100644 --- a/drivers/scsi/pm8001/pm8001_sas.c +++ b/drivers/scsi/pm8001/pm8001_sas.c @@ -875,6 +875,7 @@ static void pm8001_dev_gone_notify(struct domain_device *dev) unsigned long flags = 0; struct pm8001_hba_info *pm8001_ha; struct pm8001_device *pm8001_dev = dev->lldd_dev; + struct domain_device *parent_dev = dev->parent;
pm8001_ha = pm8001_find_ha_by_dev(dev); spin_lock_irqsave(&pm8001_ha->lock, flags); @@ -893,7 +894,13 @@ static void pm8001_dev_gone_notify(struct domain_device *dev) spin_lock_irqsave(&pm8001_ha->lock, flags); } PM8001_CHIP_DISP->dereg_dev_req(pm8001_ha, device_id); - pm8001_ha->phy[pm8001_dev->attached_phy].phy_attached = 0; + + /* + * The phy array only contains local phys. Thus, we cannot clear + * phy_attached for a device behind an expander. + */ + if (!(parent_dev && dev_is_expander(parent_dev->dev_type))) + pm8001_ha->phy[pm8001_dev->attached_phy].phy_attached = 0; pm8001_free_dev(pm8001_dev); } else { PM8001_DISC_DBG(pm8001_ha,