[PATCH 5.15 196/277] scsi: ufs: ufshpb: Fix a NULL check on list iterator

From: Greg Kroah-Hartman
Date: Tue Apr 12 2022 - 03:25:58 EST


From: Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx>

[ Upstream commit bfb7789bcbd901caead43861461bc8f334c90d3b ]

The list iterator is always non-NULL so the check 'if (!rgn)' is always
false and the dev_err() is never called. Move the check outside the loop
and determine if 'victim_rgn' is NULL, to fix this bug.

Link: https://lore.kernel.org/r/20220320150733.21824-1-xiam0nd.tong@xxxxxxxxx
Fixes: 4b5f49079c52 ("scsi: ufs: ufshpb: L2P map management for HPB read")
Reviewed-by: Daejun Park <daejun7.park@xxxxxxxxxxx>
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/ufs/ufshpb.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index a86d0cc50de2..f7eaf64293a4 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -870,12 +870,6 @@ static struct ufshpb_region *ufshpb_victim_lru_info(struct ufshpb_lu *hpb)
struct ufshpb_region *rgn, *victim_rgn = NULL;

list_for_each_entry(rgn, &lru_info->lh_lru_rgn, list_lru_rgn) {
- if (!rgn) {
- dev_err(&hpb->sdev_ufs_lu->sdev_dev,
- "%s: no region allocated\n",
- __func__);
- return NULL;
- }
if (ufshpb_check_srgns_issue_state(hpb, rgn))
continue;

@@ -891,6 +885,11 @@ static struct ufshpb_region *ufshpb_victim_lru_info(struct ufshpb_lu *hpb)
break;
}

+ if (!victim_rgn)
+ dev_err(&hpb->sdev_ufs_lu->sdev_dev,
+ "%s: no region allocated\n",
+ __func__);
+
return victim_rgn;
}

--
2.35.1