Improper locking in Linux kernel - CVE-2025-21908

Vulnerability identifier: #VU106802

CSH Severity: Low

CVSS v4.0: 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/E:U/U:Clear

CVE-ID: CVE-2025-21908

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

Affected software:
Linux kernel
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
SUSE Real Time Module
Public Cloud Module
SUSE Linux Enterprise Live Patching
Confidential Computing Module
Legacy Module
Development Tools Module
Basesystem Module
openSUSE Leap
Ubuntu
openEuler
kernel-livepatch-6_4_0-150600_10_39-rt
kernel-livepatch-6_4_0-150600_10_39-rt-debuginfo
kernel-livepatch-SLE15-SP6-RT_Update_11-debugsource
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-coco-vdso-debuginfo
kernel-coco_debug
kernel-coco
kernel-coco_debug-debuginfo
kernel-syms-coco
kernel-coco-devel
kernel-coco_debug-devel
kernel-coco-debugsource
reiserfs-kmp-coco
kernel-coco_debug-debugsource
kernel-coco_debug-devel-debuginfo
kernel-coco-debuginfo
reiserfs-kmp-coco-debuginfo
kernel-devel-coco
kernel-source-coco
kernel-source-azure
ocfs2-kmp-azure
cluster-md-kmp-azure
kernel-azure-vdso
kernel-azure-optional-debuginfo
cluster-md-kmp-azure-debuginfo
kernel-azure-devel
kernel-devel-azure
kernel-azure-debugsource
kernel-azure-optional
reiserfs-kmp-azure-debuginfo
kernel-azure-extra
dlm-kmp-azure
kernel-azure-extra-debuginfo
gfs2-kmp-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-azure
kernel-azure-vdso-debuginfo
kselftests-kmp-azure-debuginfo
dlm-kmp-azure-debuginfo
kernel-azure-debuginfo
ocfs2-kmp-azure-debuginfo
gfs2-kmp-azure
kernel-syms-azure
reiserfs-kmp-azure
kselftests-kmp-azure
kernel-rt-extra
gfs2-kmp-rt-debuginfo
kernel-rt-vdso
kernel-rt-debugsource
cluster-md-kmp-rt
dlm-kmp-rt-debuginfo
kernel-rt-vdso-debuginfo
kernel-rt-optional-debuginfo
reiserfs-kmp-rt-debuginfo
kernel-rt-devel-debuginfo
reiserfs-kmp-rt
gfs2-kmp-rt
kernel-rt_debug-vdso-debuginfo
kernel-rt-livepatch-devel
kselftests-kmp-rt-debuginfo
ocfs2-kmp-rt-debuginfo
kernel-rt_debug-vdso
kernel-rt_debug
kernel-rt
kernel-source-rt
kernel-devel-rt
kernel-rt-devel
kernel-rt-extra-debuginfo
kernel-syms-rt
kernel-rt_debug-debuginfo
kernel-rt_debug-devel
kernel-rt_debug-devel-debuginfo
kernel-rt-debuginfo
ocfs2-kmp-rt
kernel-rt-optional
dlm-kmp-rt
kernel-rt_debug-debugsource
kselftests-kmp-rt
cluster-md-kmp-rt-debuginfo
ocfs2-kmp-default-debuginfo
kernel-source
gfs2-kmp-default-debuginfo
dlm-kmp-default
cluster-md-kmp-default-debuginfo
ocfs2-kmp-default
cluster-md-kmp-default
dlm-kmp-default-debuginfo
gfs2-kmp-default
kernel-default-debuginfo
kernel-default-debugsource
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-default
kernel-default-extra-debuginfo
kernel-obs-build
kernel-syms
kernel-obs-build-debugsource
kernel-docs
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
kernel-macros
kernel-devel
kernel-default-devel
kernel-default-devel-debuginfo
kernel-64kb-devel-debuginfo
kernel-64kb-debuginfo
kernel-64kb-debugsource
kernel-64kb-devel
kernel-64kb
kernel-default-livepatch-devel
kernel-default-livepatch
kernel-default-extra
kernel-default-base
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-headers
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo
linux (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-azure-nvidia (Ubuntu package)
linux-azure (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-raspi (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime (Ubuntu package)
linux-realtime-6.8 (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-oem-6.11 (Ubuntu package)

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

The vulnerability exists due to improper locking within the kcompactd() function in mm/compaction.c, within the nfs_release_folio() function in fs/nfs/file.c. A local user can perform a denial of service (DoS) attack.

Install update from vendor's website.

• https://git.kernel.org/stable/c/5ae31c54cff745832b9bd5b32e71f3d1b607cd1e
• https://git.kernel.org/stable/c/8253ff29edcb429a9a6c75710941c6a16a9a34b1
• https://git.kernel.org/stable/c/ab0727d6e2196682351c25c1dd112136f6991f11
• https://git.kernel.org/stable/c/ce6d9c1c2b5cc785016faa11b48b6cd317eb367e
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.19
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.7
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.14
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.6.83