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Fencer Vulns
medium 5.5

CVE-2022-50091 json

locking/csd_lock: Change csdlock_debug from early_param to __setup

published 2025-06-18 16 mo ago modified 2026-11-05 3 d ago also EUVD-2022-55357

cvss
5.5
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 16%
public exploits
0
none known

Summary

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

locking/csd_lock: Change csdlock_debug from early_param to __setup

The csdlock_debug kernel-boot parameter is parsed by the early_param() function csdlock_debug(). If set, csdlock_debug() invokes static_branch_enable() to enable csd_lock_wait feature, which triggers a panic on arm64 for kernels built with CONFIG_SPARSEMEM=y and CONFIG_SPARSEMEM_VMEMMAP=n.

With CONFIG_SPARSEMEM_VMEMMAP=n, __nr_to_section is called in static_key_enable() and returns NULL, resulting in a NULL dereference because mem_section is initialized only later in sparse_init().

This is also a problem for powerpc because early_param() functions are invoked earlier than jump_label_init(), also resulting in static_key_enable() failures. These failures cause the warning "static key 'xxx' used before call to jump_label_init()".

Thus, early_param is too early for csd_lock_wait to run static_branch_enable(), so changes it to __setup to fix these.

Patch / fix

  • Linux Linux 5.15.61, 5.18.18, 5.19.2, 6.0
  • linux Debian 14, Debian 13, Debian 12 6.0.2-1

debian advisories DEBIAN-CVE-2022-50091

  • linux Ubuntu 22.04 LTS 5.15.0-53.59
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1023.27
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1022.29
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1020.25
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1018.21
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1021.26
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1023.29
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1008.12

ubuntu advisories UBUNTU-CVE-2022-50091

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 5.14.0-362.8.1.el9_3
  • rv RHEL 9 5.14.0-362.8.1.el9_3
  • perf RHEL 9 5.14.0-362.8.1.el9_3
  • rtla RHEL 9 5.14.0-362.8.1.el9_3
  • bpftool RHEL 9 7.2.0-362.8.1.el9_3
  • libperf RHEL 9 5.14.0-362.8.1.el9_3
  • kernel-rt RHEL 9 5.14.0-362.8.1.el9_3
  • kernel-64k RHEL 9 5.14.0-362.8.1.el9_3

red hat advisories RHSA-2023:6583

  • kernel-rt SLE Micro 5.2, SLE Micro 5.1 5.3.18-150300.214.1
  • kernel-source-rt SLE Micro 5.2, SLE Micro 5.1 5.3.18-150300.214.1
  • kernel-64kb SLES 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.211.1
  • kernel-syms SLES for SAP 15 SP3, SLES 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.211.1
  • kernel-source SLES for SAP 15 SP3, SLES 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.211.1
  • kernel-default SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Micro 5.2 +4 more 5.3.18-150300.59.211.1
  • kernel-preempt SLES for SAP 15 SP3, SLES 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.211.1
  • kernel-obs-build SLES for SAP 15 SP3, SLES 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.212.1

suse advisories SUSE-SU-2025:02334-1SUSE-SU-2025:02320-1SUSE-SU-2025:02308-1

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-2022-50091 updated cvss 7.0

kernel: locking/csd_lock: Change csdlock_debug from early_param to __setup

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: workaround, no fix available
  • 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 Red Hat Enterprise Linux 10 kernel
    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
3 d ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.