From: Juntong Deng <juntong.deng@outlook.com> stable inclusion from stable-v5.10.202 commit c6c8863fb3f57700ab583d875adda04caaf2278a category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RG40 CVE: CVE-2023-52804 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 64933ab7b04881c6c18b21ff206c12278341c72e ] Both db_maxag and db_agpref are used as the index of the db_agfree array, but there is currently no validity check for db_maxag and db_agpref, which can lead to errors. The following is related bug reported by Syzbot: UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:639:20 index 7936 is out of range for type 'atomic_t[128]' Add checking that the values of db_maxag and db_agpref are valid indexes for the db_agfree array. Reported-by: syzbot+38e876a8aa44b7115c76@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=38e876a8aa44b7115c76 Signed-off-by: Juntong Deng <juntong.deng@outlook.com> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Wang Hai <wanghai38@huawei.com> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- fs/jfs/jfs_dmap.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index b0a65aaed43e..2b749a7af316 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -188,6 +188,12 @@ int dbMount(struct inode *ipbmap) bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel); bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag); bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref); + if (bmp->db_maxag >= MAXAG || bmp->db_maxag < 0 || + bmp->db_agpref >= MAXAG || bmp->db_agpref < 0) { + err = -EINVAL; + goto err_release_metapage; + } + bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel); bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight); bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); -- 2.39.2