From:   zhangyue <zhangyue1@kylinos.cn>
To:     darrick.wong@oracle.com, linux-xfs@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org
Subject: [PATCH] xfs: fix the problem that the array may be out of bound
Date:   Fri, 19 Nov 2021 16:17:58 +0800
Message-Id: <20211119081758.399167-1-zhangyue1@kylinos.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

In function 'xfs_btree_delrec()', if all data in array
'cur->bc_ptrs[level]' is 0, the 'level' may be greater than
or equal to 'XFS_BTREE_MAXLEVELS'.

At this time, the array may be out of bound.

Signed-off-by: zhangyue <zhangyue1@kylinos.cn>
---
 fs/xfs/libxfs/xfs_btree.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index bbdae2b4559f..fe66d1adc169 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -3694,6 +3694,9 @@ xfs_btree_delrec(
 	tcur = NULL;
 
 	/* Get the index of the entry being deleted, check for nothing there. */
+	if (level >= XFS_BTREE_MAXLEVELS)
+		return -EFSCORRUPTED;
+
 	ptr = cur->bc_ptrs[level];
 	if (ptr == 0) {
 		*stat = 0;
-- 
2.30.0