5.5

CVE-2022-50091: locking/csd_lock: Change csdlock_debug from early_param to __setup

Analyzed
AliasesUBUNTU-CVE-2022-50091DEBIAN-CVE-2022-50091
Published 18-06-2025Last modified 11-05-2026

Vulnerability summary

CVE-2022-50091 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.25%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 4 · Related 3
RHSA-2023:6583SUSE-SU-2025:02308-1SUSE-SU-2025:02320-1SUSE-SU-2025:02334-1

Timeline

  1. 18-06-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

17%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.25% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu94 products
  • linux< 5.15.0-53.59
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1023.27
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 8d0968cc6b8ffd8496c2ebffdfdc801f949a85e5, < d2cbdbe22b5f190055d2d0ae92e7454479343a30 | ≥ 8d0968cc6b8ffd8496c2ebffdfdc801f949a85e5, < 05de9e2e33b1625c71aee69e353fe906dd2be88a | ≥ 8d0968cc6b8ffd8496c2ebffdfdc801f949a85e5, < b480d1e9a8c11ecc1c99dc01814b28e3103bd0a0 | ≥ 8d0968cc6b8ffd8496c2ebffdfdc801f949a85e5, < 9c9b26b0df270d4f9246e483a44686fca951a29c | 5.13
  • linux_kernel≥ 5.13, < 5.15.61 | ≥ 5.16, < 5.18.18 | ≥ 5.19, < 5.19.2
Debian1 product
  • linux< 6.0.2-1

3 vendors · 97 products

References

7 links