NULL pointer dereference in Linux kernel - CVE-2025-21989

Vulnerability identifier: #VU106671

CSH Severity: Low

CVSS v4: 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]

CVE-ID: CVE-2025-21989

CWE-ID: CWE-476

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to NULL pointer dereference within the dce60_timing_generator_construct() function in drivers/gpu/drm/amd/display/dc/dce60/dce60_timing_generator.c. A local user can perform a denial of service (DoS) attack.

Linux kernel
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Workstation Extension 15
Development Tools Module
Public Cloud Module
SUSE Linux Enterprise Live Patching
Legacy Module
Basesystem Module
Ubuntu
kernel-livepatch-6_4_0-150700_53_3-default
kernel-livepatch-6_4_0-150700_53_3-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_1-debugsource
kernel-source-azure
kernel-devel-azure
kernel-syms-azure
kernel-azure-debuginfo
kernel-azure-debugsource
kernel-azure-devel-debuginfo
kernel-azure-devel
kernel-azure
kernel-default-devel-debuginfo
reiserfs-kmp-default
kernel-default-devel
kernel-devel
kernel-macros
kernel-zfcpdump
kernel-zfcpdump-debuginfo
kernel-zfcpdump-debugsource
kernel-docs
kernel-obs-build-debugsource
kernel-syms
kernel-obs-build
kernel-source
gfs2-kmp-default-debuginfo
kernel-default
reiserfs-kmp-default-debuginfo
kernel-default-debugsource
kernel-default-debuginfo
gfs2-kmp-default
dlm-kmp-default-debuginfo
cluster-md-kmp-default
ocfs2-kmp-default
cluster-md-kmp-default-debuginfo
dlm-kmp-default
ocfs2-kmp-default-debuginfo
kernel-default-extra
kernel-default-extra-debuginfo
kernel-default-livepatch
kernel-default-livepatch-devel
kernel-64kb
kernel-64kb-devel
kernel-64kb-debugsource
kernel-64kb-debuginfo
kernel-64kb-devel-debuginfo
kernel-default-base
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-azure (Ubuntu package)
linux-oem-6.11 (Ubuntu package)

Install update from vendor's website.

Linux kernel - update to 6.12.20
kernel-livepatch-6_4_0-150700_53_3-default - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_3-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_1-debugsource - update to 1-150700.15.3.1
kernel-source-azure - update to 6.4.0-150700.20.3.1
kernel-devel-azure - update to 6.4.0-150700.20.3.1
kernel-syms-azure - update to 6.4.0-150700.20.3.1
kernel-azure-debuginfo - update to 6.4.0-150700.20.3.1
kernel-azure-debugsource - update to 6.4.0-150700.20.3.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.20.3.1
kernel-azure-devel - update to 6.4.0-150700.20.3.1
kernel-azure - update to 6.4.0-150700.20.3.1
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.3.1
reiserfs-kmp-default - update to 6.4.0-150700.53.3.1
kernel-default-devel - update to 6.4.0-150700.53.3.1
kernel-devel - update to 6.4.0-150700.53.3.1
kernel-macros - update to 6.4.0-150700.53.3.1
kernel-zfcpdump - update to 6.4.0-150700.53.3.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.3.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.3.1
kernel-docs - update to 6.4.0-150700.53.3.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.3.1
kernel-syms - update to 6.4.0-150700.53.3.1
kernel-obs-build - update to 6.4.0-150700.53.3.1
kernel-source - update to 6.4.0-150700.53.3.1
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.3.1
kernel-default - update to 6.4.0-150700.53.3.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.3.1
kernel-default-debugsource - update to 6.4.0-150700.53.3.1
kernel-default-debuginfo - update to 6.4.0-150700.53.3.1
gfs2-kmp-default - update to 6.4.0-150700.53.3.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.3.1
cluster-md-kmp-default - update to 6.4.0-150700.53.3.1
ocfs2-kmp-default - update to 6.4.0-150700.53.3.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.3.1
dlm-kmp-default - update to 6.4.0-150700.53.3.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.3.1
kernel-default-extra - update to 6.4.0-150700.53.3.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.3.1
kernel-default-livepatch - update to 6.4.0-150700.53.3.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.3.1
kernel-64kb - update to 6.4.0-150700.53.3.1
kernel-64kb-devel - update to 6.4.0-150700.53.3.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.3.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.3.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.3.1
kernel-default-base - update to 6.4.0-150700.53.3.1.150700.17.2.1
linux (Ubuntu package) - addressed in versions 6.11.0-28.28, 6.11.0-28.28~24.04.1, 6.11.0-1011.11, 6.11.0-1014.14, 6.11.0-1015.16, 6.11.0-1016.16, 6.11.0-1016.16~24.04.1, 6.11.0-1017.18
linux-lowlatency (Ubuntu package) - addressed in versions 6.11.0-1015.16, 6.11.0-1015.16~24.04.2
linux-azure (Ubuntu package) - addressed in versions 6.11.0-1018.18, 6.11.0-1018.18~24.04.1
linux-oem-6.11 (Ubuntu package) - update to 6.11.0-1024.24

• https://git.kernel.org/stable/c/36d04c9313d8d83ead92242f037099ac73e02120
• https://git.kernel.org/stable/c/e204aab79e01bc8ff750645666993ed8b719de57
• https://git.kernel.org/stable/c/fefa811e616b5d0b555ed65743e528a0a8a0b377
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.20

• NULL pointer dereference in Linux kernel dc dce60 driver
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• Ubuntu update for linux
• Ubuntu update for linux-oem-6.11
• Ubuntu update for linux-lowlatency
• Ubuntu update for linux-azure