Commit 999093a8 authored by ZhaoLong Wang's avatar ZhaoLong Wang
Browse files

mtd: Fix gluebi NULL pointer dereference caused by ftl notifier

stable inclusion
from stable-v5.10.209
commit 001a3f59d8c914ef8273461d4bf495df384cc5f8
category: bugfix
bugzilla: 189540, https://gitee.com/src-openeuler/kernel/issues/I932W5
CVE: CVE-2023-52449

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=001a3f59d8c914ef8273461d4bf495df384cc5f8

--------------------------------

[ Upstream commit a43bdc376deab5fff1ceb93dca55bcab8dbdc1d6 ]

If both ftl.ko and gluebi.ko are loaded, the notifier of ftl
triggers NULL pointer dereference when trying to access
‘gluebi->desc’ in gluebi_read().

ubi_gluebi_init
  ubi_register_volume_notifier
    ubi_enumerate_volumes
      ubi_notify_all
        gluebi_notify    nb->notifier_call()
          gluebi_create
            mtd_device_register
              mtd_device_parse_register
                add_mtd_device
                  blktrans_notify_add   not->add()
                    ftl_add_mtd         tr->add_mtd()
                      scan_header
                        mtd_read
                          mtd_read_oob
                            mtd_read_oob_std
                              gluebi_read   mtd->read()
                                gluebi->desc - NULL

Detailed reproduction information available at the Link [1],

In the normal case, obtain gluebi->desc in the gluebi_get_device(),
and access gluebi->desc in the gluebi_read(). However,
gluebi_get_device() is not executed in advance in the
ftl_add_mtd() process, which leads to NULL pointer dereference.

The solution for the gluebi module is to run jffs2 on the UBI
volume without considering working with ftl or mtdblock [2].
Therefore, this problem can be avoided by preventing gluebi from
creating the mtdblock device after creating mtd partition of the
type MTD_UBIVOLUME.

Fixes: 2ba3d76a ("UBI: make gluebi a separate module")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217992 [1]
Link: https://lore.kernel.org/lkml/441107100.23734.1697904580252.JavaMail.zimbra@nod.at/

 [2]
Signed-off-by: default avatarZhaoLong Wang <wangzhaolong1@huawei.com>
Reviewed-by: default avatarZhihao Cheng <chengzhihao1@huawei.com>
Acked-by: default avatarRichard Weinberger <richard@nod.at>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20231220024619.2138625-1-wangzhaolong1@huawei.com


Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Conflicts:
	drivers/mtd/mtd_blkdevs.c
Signed-off-by: default avatarZhaoLong Wang <wangzhaolong1@huawei.com>
parent 4fee6fde
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