2022-03-21 20:52:39

by Xiaomeng Tong

Subject: [PATCH v2] ufs: fix an NULL check on list iterator

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.

Fixes: 4b5f49079c52a ("scsi: ufs: ufshpb: L2P map management for HPB read")
Signed-off-by: Xiaomeng Tong <[email protected]>
---
changes since v1:
- move the check outside the loop (Jakob Koschel)
v1: https://lore.kernel.org/all/[email protected]/
---
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 2d36a0715fca..b34feba1f53d 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -869,12 +869,6 @@ 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;

@@ -890,6 +884,11 @@ 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;
}


base-commit: 14702b3b2438e2f2d07ae93b5d695c166e5c83d1
--
2.17.1

2022-03-21 23:59:11

by Daejun Park

Subject: RE: [PATCH v2] ufs: fix an NULL check on list iterator

Hi Xiaomeng Tong,

>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.
>
>Fixes: 4b5f49079c52a ("scsi: ufs: ufshpb: L2P map management for HPB read")
>Signed-off-by: Xiaomeng Tong <[email protected]>
>---

Good catch. Free to add my reviewed-by tag.

Reviewed-by: Daejun Park <[email protected]>

Thanks,
Daejun