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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Daejun Park <daejun7.park@samsung.com>,
        Xiaomeng Tong <xiam0nd.tong@gmail.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 196/277] scsi: ufs: ufshpb: Fix a NULL check on list iterator
Date:   Tue, 12 Apr 2022 08:29:59 +0200
Message-Id: <20220412062947.710841093@linuxfoundation.org>
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From: Xiaomeng Tong <xiam0nd.tong@gmail.com>

[ 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@gmail.com
Fixes: 4b5f49079c52 ("scsi: ufs: ufshpb: L2P map management for HPB read")
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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