[PATCH 4/4] scsi: hisi_sas: Fix out of bound at debug_I_T_nexus_reset()

[Ike Panhc]

From: Luo Jiaxing <luojiaxing at huawei.com>

BugLink: https://launchpad.net/bugs/1853992

Fix a possible out-of-bounds access in hisi_sas_debug_I_T_nexus_reset().

Signed-off-by: Luo Jiaxing <luojiaxing at huawei.com>
Signed-off-by: John Garry <john.garry at huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
(cherry picked from commit 445ee2de112a18419aeae72fdae4221cd90f2948)
Signed-off-by: Ike Panhc <ike.pan at canonical.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 7fe85073f5cf..2c62823123ea 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1757,13 +1757,14 @@ static int hisi_sas_debug_I_T_nexus_reset(struct domain_device *device)
 	struct hisi_sas_device *sas_dev = device->lldd_dev;
 	struct hisi_hba *hisi_hba = dev_to_hisi_hba(device);
 	struct sas_ha_struct *sas_ha = &hisi_hba->sha;
-	struct asd_sas_phy *sas_phy = sas_ha->sas_phy[local_phy->number];
-	struct hisi_sas_phy *phy = container_of(sas_phy,
-			struct hisi_sas_phy, sas_phy);
 	DECLARE_COMPLETION_ONSTACK(phyreset);
 	int rc, reset_type;
 
 	if (scsi_is_sas_phy_local(local_phy)) {
+		struct asd_sas_phy *sas_phy =
+			sas_ha->sas_phy[local_phy->number];
+		struct hisi_sas_phy *phy =
+			container_of(sas_phy, struct hisi_sas_phy, sas_phy);
 		phy->in_reset = 1;
 		phy->reset_completion = &phyreset;
 	}
@@ -1775,6 +1776,10 @@ static int hisi_sas_debug_I_T_nexus_reset(struct domain_device *device)
 	sas_put_local_phy(local_phy);
 
 	if (scsi_is_sas_phy_local(local_phy)) {
+		struct asd_sas_phy *sas_phy =
+			sas_ha->sas_phy[local_phy->number];
+		struct hisi_sas_phy *phy =
+			container_of(sas_phy, struct hisi_sas_phy, sas_phy);
 		int ret = wait_for_completion_timeout(&phyreset, 2 * HZ);
 		unsigned long flags;
 
-- 
2.17.1