SB20260917153 - Improper update of reference count in Linux kernel gpu drm driver



SB20260917153 - Improper update of reference count in Linux kernel gpu drm driver

Published: September 17, 2026

Security Bulletin ID SB20260917153
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Partial DoS

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper update of reference count (CVE-ID: CVE-2026-89816)

CWE-ID: CWE-911 - Improper Update of Reference Count

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause a memory leak.

The vulnerability exists due to improper reference counting in complete_signaling() in the DRM atomic UAPI when an atomic DRM ioctl using DRM_MODE_PAGE_FLIP_EVENT is blocked while waiting for fences. A local user can issue the atomic DRM ioctl with a sw_sync fence and send a signal to the blocked thread to cause a memory leak.

The condition was observed with amdgpu and vkms.


Remediation

Install update from vendor's website.