SB20260812164 - Use-after-free in Linux kernel watchdog driver



SB20260812164 - Use-after-free in Linux kernel watchdog driver

Published: August 12, 2026

Security Bulletin ID SB20260812164
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) Use-after-free (CVE-ID: CVE-2026-68357)

CWE-ID: CWE-416 - Use After Free

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 a use-after-free in watchdog_unregister_governor() and the watchdog pretimeout governor handling logic when unregistering a watchdog governor that is still referenced as default_gov. A local user can trigger governor unregistration and subsequent watchdog device registration or reassignment to cause a denial of service.

The issue occurs when the unregistered governor remains referenced through a dangling default_gov pointer, affecting both newly registered watchdog devices and existing devices whose governor is reassigned.


Remediation

Install update from vendor's website.