diff options
| author | ZhaoLong Wang <wangzhaolong1@huawei.com> | 2023-12-20 10:46:19 +0800 |
|---|---|---|
| committer | Miquel Raynal <miquel.raynal@bootlin.com> | 2023-12-22 12:33:24 +0100 |
| commit | a43bdc376deab5fff1ceb93dca55bcab8dbdc1d6 (patch) | |
| tree | 6dcc1115010404718cf794d6aec97f18b7b3d8f9 /drivers/mtd | |
| parent | b9e824f995ad46246fcc06bd43dc252916c32481 (diff) | |
| download | lwn-a43bdc376deab5fff1ceb93dca55bcab8dbdc1d6.tar.gz lwn-a43bdc376deab5fff1ceb93dca55bcab8dbdc1d6.zip | |
mtd: Fix gluebi NULL pointer dereference caused by ftl notifier
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: 2ba3d76a1e29 ("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: ZhaoLong Wang <wangzhaolong1@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20231220024619.2138625-1-wangzhaolong1@huawei.com
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/mtd_blkdevs.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c index ff18636e0889..5bc32108ca03 100644 --- a/drivers/mtd/mtd_blkdevs.c +++ b/drivers/mtd/mtd_blkdevs.c @@ -463,7 +463,7 @@ static void blktrans_notify_add(struct mtd_info *mtd) { struct mtd_blktrans_ops *tr; - if (mtd->type == MTD_ABSENT) + if (mtd->type == MTD_ABSENT || mtd->type == MTD_UBIVOLUME) return; list_for_each_entry(tr, &blktrans_majors, list) @@ -503,7 +503,7 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr) mutex_lock(&mtd_table_mutex); list_add(&tr->list, &blktrans_majors); mtd_for_each_device(mtd) - if (mtd->type != MTD_ABSENT) + if (mtd->type != MTD_ABSENT && mtd->type != MTD_UBIVOLUME) tr->add_mtd(tr, mtd); mutex_unlock(&mtd_table_mutex); return 0; |