SB20260727147 - Improper locking in Linux kernel gpio driver



SB20260727147 - Improper locking in Linux kernel gpio driver

Published: July 27, 2026

Security Bulletin ID SB20260727147
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper locking (CVE-ID: CVE-2026-64428)

CWE-ID: CWE-667 - Improper Locking

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper lock type selection in the sch irq startup path when starting up a requested irq on PREEMPT_RT systems. A local user can request a threaded irq that reaches sch_irq_unmask() and sch_irq_mask_unmask() to cause a denial of service.

The issue occurs because the path is not sleepable, but a regular spinlock_t becomes a sleeping lock on PREEMPT_RT.


Remediation

Install update from vendor's website.