[PATCH AUTOSEL 6.10 113/121] scsi: pm80xx: Set phy->enable_completion only when we wait for it

Sasha Levin
2024-08-01T00:18:19Z

From: Igor Pylypiv <ipylypiv@google.com>

[ Upstream commit e4f949ef1516c0d74745ee54a0f4882c1f6c7aea ]

pm8001_phy_control() populates the enable_completion pointer with a stack
address, sends a PHY_LINK_RESET / PHY_HARD_RESET, waits 300 ms, and
returns. The problem arises when a phy control response comes late. After
300 ms the pm8001_phy_control() function returns and the passed
enable_completion stack address is no longer valid. Late phy control
response invokes complete() on a dangling enable_completion pointer which
leads to a kernel crash.

Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Signed-off-by: Terrence Adams <tadamsjr@google.com>
Link: https://lore.kernel.org/r/20240627155924.2361370-2-tadamsjr@google.com
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/pm8001/pm8001_sas.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index a5a31dfa45122..ee2da8e49d4cf 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -166,7 +166,6 @@ int pm8001_phy_control(struct asd_sas_phy *sas_phy, enum phy_func func,
unsigned long flags;
pm8001_ha = sas_phy->ha->lldd_ha;
phy = &pm8001_ha->phy[phy_id];
- pm8001_ha->phy[phy_id].enable_completion = &completion;

if (PM8001_CHIP_DISP->fatal_errors(pm8001_ha)) {
/*
@@ -190,6 +189,7 @@ int pm8001_phy_control(struct asd_sas_phy *sas_phy, enum phy_func func,
rates->maximum_linkrate;
}
if (pm8001_ha->phy[phy_id].phy_state == PHY_LINK_DISABLE) {
+ pm8001_ha->phy[phy_id].enable_completion = &completion;
PM8001_CHIP_DISP->phy_start_req(pm8001_ha, phy_id);
wait_for_completion(&completion);
}
@@ -198,6 +198,7 @@ int pm8001_phy_control(struct asd_sas_phy *sas_phy, enum phy_func func,
break;
case PHY_FUNC_HARD_RESET:
if (pm8001_ha->phy[phy_id].phy_state == PHY_LINK_DISABLE) {
+ pm8001_ha->phy[phy_id].enable_completion = &completion;
PM8001_CHIP_DISP->phy_start_req(pm8001_ha, phy_id);
wait_for_completion(&completion);
}
@@ -206,6 +207,7 @@ int pm8001_phy_control(struct asd_sas_phy *sas_phy, enum phy_func func,
break;
case PHY_FUNC_LINK_RESET:
if (pm8001_ha->phy[phy_id].phy_state == PHY_LINK_DISABLE) {
+ pm8001_ha->phy[phy_id].enable_completion = &completion;
PM8001_CHIP_DISP->phy_start_req(pm8001_ha, phy_id);
wait_for_completion(&completion);
}
--
2.43.0