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Fencer Vulns
medium 4.4

CVE-2023-52771 json

cxl/port: Fix delete_endpoint() vs parent unregistration race

published 2024-05-21 2 y ago modified 2026-10-30 10 d ago also EUVD-2023-59488

cvss
4.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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

cxl/port: Fix delete_endpoint() vs parent unregistration race

The CXL subsystem, at cxl_mem ->probe() time, establishes a lineage of ports (struct cxl_port objects) between an endpoint and the root of a CXL topology. Each port including the endpoint port is attached to the cxl_port driver.

Given that setup, it follows that when either any port in that lineage goes through a cxl_port ->remove() event, or the memdev goes through a cxl_mem ->remove() event. The hierarchy below the removed port, or the entire hierarchy if the memdev is removed needs to come down.

The delete_endpoint() callback is careful to check whether it is being called to tear down the hierarchy, or if it is only being called to teardown the memdev because an ancestor port is going through ->remove().

That care needs to take the device_lock() of the endpoint's parent. Which requires 2 bugs to be fixed:

1/ A reference on the parent is needed to prevent use-after-free scenarios like this signature:

BUG: spinlock bad magic on CPU#0, kworker/u56:0/11 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230524-3.fc38 05/24/2023 Workqueue: cxl_port detach_memdev [cxl_core] RIP: 0010:spin_bug+0x65/0xa0 Call Trace: do_raw_spin_lock+0x69/0xa0 __mutex_lock+0x695/0xb80 delete_endpoint+0xad/0x150 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 detach_memdev+0x15/0x20 [cxl_core] process_one_work+0x1e3/0x4c0 worker_thread+0x1dd/0x3d0

2/ In the case of RCH topologies, the parent device that needs to be locked is not always @port->dev as returned by cxl_mem_find_port(), use endpoint->dev.parent instead.

Patch / fix

  • Linux Linux 6.1.191, 6.5.13, 6.6.3, 6.7
  • linux Debian 14, Debian 13 6.5.13-1

debian advisories DEBIAN-CVE-2023-52771

  • linux-nvidia-6.5 Ubuntu 22.04 LTS 6.5.0-1014.14

ubuntu advisories UBUNTU-CVE-2023-52771

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

  • kernel RHEL 9 5.14.0-427.33.1.el9_4
  • rv RHEL 9 5.14.0-427.33.1.el9_4
  • perf RHEL 9 5.14.0-427.33.1.el9_4
  • rtla RHEL 9 5.14.0-427.33.1.el9_4
  • bpftool RHEL 9 7.3.0-427.33.1.el9_4
  • libperf RHEL 9 5.14.0-427.33.1.el9_4
  • kernel-rt RHEL 9 5.14.0-427.33.1.el9_4
  • kernel-64k RHEL 9 5.14.0-427.33.1.el9_4

red hat advisories RHSA-2024:5928RHSA-2024:5364RHSA-2024:5365

  • kernel-rt Linux Micro 6.0 6.4.0-9.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-9.1
  • kernel-source Linux Micro 6.0 6.4.0-18.1
  • kernel-default Linux Micro 6.0 6.4.0-18.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-18.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1

suse advisories SUSE-SU-2025:20028-1SUSE-SU-2025:20008-1SUSE-SU-2024:2973-1SUSE-SU-2024:2203-1SUSE-SU-2024:2135-1

  • kernel AlmaLinux 9 5.14.0-427.33.1.el9_4
  • rv AlmaLinux 9 5.14.0-427.33.1.el9_4
  • perf AlmaLinux 9 5.14.0-427.33.1.el9_4
  • rtla AlmaLinux 9 5.14.0-427.33.1.el9_4
  • bpftool AlmaLinux 9 7.3.0-427.33.1.el9_4
  • libperf AlmaLinux 9 5.14.0-427.33.1.el9_4
  • kernel-rt AlmaLinux 9 5.14.0-427.33.1.el9_4
  • kernel-64k AlmaLinux 9 5.14.0-427.33.1.el9_4

almalinux advisories ALSA-2024:5928

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-2023-52771 updated cvss 4.4

kernel: cxl/port: Fix delete_endpoint() vs parent unregistration race

  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-debuginfo-common-s390x 5.14.0-284.79.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.79.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.79.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.79.1.el9_2
    fixed: vendor fix RHSA-2024:5364
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.33.1.el9_4, perf 5.14.0-427.33.1.el9_4, rtla 5.14.0-427.33.1.el9_4, kernel-devel-matched 5.14.0-427.33.1.el9_4, kernel-64k-devel-matched 5.14.0-427.33.1.el9_4, kernel-debug-devel-matched 5.14.0-427.33.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:5928
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) perf 5.14.0-284.79.1.el9_2, rtla 5.14.0-284.79.1.el9_2, kernel-devel-matched 5.14.0-284.79.1.el9_2, kernel-64k-devel-matched 5.14.0-284.79.1.el9_2, kernel-debug-devel-matched 5.14.0-284.79.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.79.1.el9_2, +5 more
    fixed: vendor fix RHSA-2024:5364
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.33.1.el9_4, kernel 5.14.0-427.33.1.el9_4, kernel-64k 5.14.0-427.33.1.el9_4, kernel-core 5.14.0-427.33.1.el9_4, kernel-tools 5.14.0-427.33.1.el9_4, python3-perf 5.14.0-427.33.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:5928
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool 7.0.0-284.79.1.el9_2, kernel 5.14.0-284.79.1.el9_2, kernel-64k 5.14.0-284.79.1.el9_2, kernel-core 5.14.0-284.79.1.el9_2, kernel-tools 5.14.0-284.79.1.el9_2, python3-perf 5.14.0-284.79.1.el9_2, +28 more
    fixed: vendor fix RHSA-2024:5364
  • Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.33.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.33.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.33.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.33.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.33.1.el9_4 Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.33.1.el9_4, kernel-rt-kvm 5.14.0-427.33.1.el9_4, kernel-rt-core 5.14.0-427.33.1.el9_4, kernel-rt-modules 5.14.0-427.33.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.33.1.el9_4, kernel-rt-debug-core 5.14.0-427.33.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:5928
  • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-core 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-modules 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-debug-core 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-modules-core 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-debug-modules 5.14.0-284.79.1.rt14.364.el9_2, +4 more Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-kvm 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-core 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-modules 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-debug-kvm 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-debug-core 5.14.0-284.79.1.rt14.364.el9_2, +6 more
    fixed: vendor fix RHSA-2024:5365
show 2 more
  • Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.33.1.el9_4, kernel-rt-core 5.14.0-427.33.1.el9_4, kernel-rt-modules 5.14.0-427.33.1.el9_4, kernel-rt-debug-core 5.14.0-427.33.1.el9_4, kernel-rt-modules-core 5.14.0-427.33.1.el9_4, kernel-rt-debug-modules 5.14.0-427.33.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:5928
  • 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 Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    not affected: vulnerable code not present

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

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 4.4 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 4.4 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
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.