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Fencer Vulns
high 7.8

CVE-2023-52468 json

class: fix use-after-free in class_register()

published 2024-02-25 2 y ago modified 2026-06-17 4 mo ago also EUVD-2023-57093

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits
0
none known

Summary

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

class: fix use-after-free in class_register()

The lock_class_key is still registered and can be found in lock_keys_hash hlist after subsys_private is freed in error handler path.A task who iterate over the lock_keys_hash later may cause use-after-free.So fix that up and unregister the lock_class_key before kfree(cp).

On our platform, a driver fails to kset_register because of creating duplicate filename '/class/xxx'.With Kasan enabled, it prints a invalid-access bug report.

KASAN bug report:

BUG: KASAN: invalid-access in lockdep_register_key+0x19c/0x1bc Write of size 8 at addr 15ffff808b8c0368 by task modprobe/252 Pointer tag: [15], memory tag: [fe]

CPU: 7 PID: 252 Comm: modprobe Tainted: G W 6.6.0-mainline-maybe-dirty #1

Call trace: dump_backtrace+0x1b0/0x1e4 show_stack+0x2c/0x40 dump_stack_lvl+0xac/0xe0 print_report+0x18c/0x4d8 kasan_report+0xe8/0x148 __hwasan_store8_noabort+0x88/0x98 lockdep_register_key+0x19c/0x1bc class_register+0x94/0x1ec init_module+0xbc/0xf48 [rfkill] do_one_initcall+0x17c/0x72c do_init_module+0x19c/0x3f8 ... Memory state around the buggy address: ffffff808b8c0100: 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a ffffff808b8c0200: 8a 8a 8a 8a 8a 8a 8a 8a fe fe fe fe fe fe fe fe >ffffff808b8c0300: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ^ ffffff808b8c0400: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03

As CONFIG_KASAN_GENERIC is not set, Kasan reports invalid-access not use-after-free here.In this case, modprobe is manipulating the corrupted lock_keys_hash hlish where lock_class_key is already freed before.

It's worth noting that this only can happen if lockdep is enabled, which is not true for normal system.

Patch / fix

  • Linux Linux 6.6.14, 6.7.2, 6.8
  • linux Debian 14, Debian 13 6.6.15-1

debian advisories DEBIAN-CVE-2023-52468

  • linux-gcp-6.5 Ubuntu 22.04 LTS 6.5.0-1022.24~22.04.1
  • linux-hwe-6.5 Ubuntu 22.04 LTS 6.5.0-41.41~22.04.2
  • linux-oem-6.5 Ubuntu 22.04 LTS 6.5.0-1024.25
  • linux-azure-6.5 Ubuntu 22.04 LTS 6.5.0-1022.23~22.04.1
  • linux-riscv-6.5 Ubuntu 22.04 LTS 6.5.0-40.40.1~22.04.1
  • linux-nvidia-6.5 Ubuntu 22.04 LTS 6.5.0-1021.22
  • linux-oracle-6.5 Ubuntu 22.04 LTS 6.5.0-1024.24~22.04.1
  • linux-starfive-6.5 Ubuntu 22.04 LTS 6.5.0-1015.16~22.04.1

ubuntu advisories UBUNTU-CVE-2023-52468

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-52468 updated cvss 4.4

kernel: use-after-free in class_register()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix planned “Will not fix”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.