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From:   linan666@huaweicloud.com
To:     richard@nod.at, miquel.raynal@bootlin.com, vigneshr@ti.com
Cc:     linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
        linan122@huawei.com, yukuai3@huawei.com, yi.zhang@huawei.com,
        houtao1@huawei.com, yangerkun@huawei.com
Subject: [PATCH] ubi: block: fix null-pointer-dereference in ubiblock_create()
Date:   Fri,  8 Dec 2023 15:13:17 +0800
Message-Id: <20231208071317.1268465-1-linan666@huaweicloud.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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From: Li Nan <linan122@huawei.com>

If idr_alloc() fails, dev->gd will be put after goto out_cleanup_disk in
ubiblock_create(), but dev->gd has not been assigned yet at this time, and
accessing it will trigger a null-pointer-dereference issue. Fix it by put
gd directly.

Signed-off-by: Li Nan <linan122@huawei.com>
---
 drivers/mtd/ubi/block.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index 309a42aeaa4c..654bd7372cd8 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -434,7 +434,7 @@ int ubiblock_create(struct ubi_volume_info *vi)
 	list_del(&dev->list);
 	idr_remove(&ubiblock_minor_idr, gd->first_minor);
 out_cleanup_disk:
-	put_disk(dev->gd);
+	put_disk(gd);
 out_free_tags:
 	blk_mq_free_tag_set(&dev->tag_set);
 out_free_dev:
-- 
2.39.2