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From:   Wenchao Hao <haowenchao2@huawei.com>
To:     Jan Kara <jack@suse.com>, <linux-kernel@vger.kernel.org>
CC:     <linfeilong@huawei.com>, Wenchao Hao <haowenchao2@huawei.com>
Subject: [PATCH 2/2] udf:check if buffer head's data when getting lvidiu
Date:   Tue, 13 Jun 2023 11:22:54 +0800
Message-ID: <20230613032254.1235752-3-haowenchao2@huawei.com>
In-Reply-To: <20230613032254.1235752-1-haowenchao2@huawei.com>
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We can not always assume udf_sb_info->s_lvid_bh's data is valid. If the
data is corrupted, we would get an incorrect offset and cause the
following code access an illegal address.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
---
 fs/udf/super.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 6304e3c5c3d9..71481b60c871 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -114,6 +114,8 @@ struct logicalVolIntegrityDescImpUse *udf_sb_lvidiu(struct super_block *sb)
 
 	if (!UDF_SB(sb)->s_lvid_bh)
 		return NULL;
+	if (!udf_check_tagged_bh(sb, UDF_SB(sb)->s_lvid_bh))
+		return NULL;
 	lvid = (struct logicalVolIntegrityDesc *)UDF_SB(sb)->s_lvid_bh->b_data;
 	partnum = le32_to_cpu(lvid->numOfPartitions);
 	/* The offset is to skip freeSpaceTable and sizeTable arrays */
-- 
2.35.3