Description

In the Linux kernel, the following vulnerability has been resolved:

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.

Classification

CVE ID: CVE-2023-52449

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/aeba358bcc8ffddf9b4a9bd0e5ec9eb338d46022
https://git.kernel.org/stable/c/1bf4fe14e97cda621522eb2f28b0a4e87c5b0745
https://git.kernel.org/stable/c/001a3f59d8c914ef8273461d4bf495df384cc5f8
https://git.kernel.org/stable/c/d8ac2537763b54d278b80b2b080e1652523c7d4c
https://git.kernel.org/stable/c/5389407bba1eab1266c6d83e226fb0840cb98dd5
https://git.kernel.org/stable/c/cfd7c9d260dc0a3baaea05a122a19ab91e193c65
https://git.kernel.org/stable/c/b36aaa64d58aaa2f2cbc8275e89bae76a2b6c3dc
https://git.kernel.org/stable/c/a43bdc376deab5fff1ceb93dca55bcab8dbdc1d6

Timeline