Improper locking in Linux kernel - CVE-2025-21871

Vulnerability identifier: #VU106122

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-2025-21871

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

Affected software:
Linux kernel
SUSE Linux Enterprise Server 12 SP5
Debian Linux
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Live Patching
Confidential Computing Module
Public Cloud Module
Legacy Module
Development Tools Module
Basesystem Module
SUSE Real Time Module
openSUSE Leap
Ubuntu
openEuler
SmartFabric Manager
APEX Cloud Platform for Microsoft Azure
kgraft-patch-4_12_14-122_255-default
kernel-livepatch-SLE15-SP6-RT_Update_10-debugsource
kernel-livepatch-6_4_0-150600_10_34-rt
kernel-livepatch-6_4_0-150600_10_34-rt-debuginfo
kernel-livepatch-6_4_0-150600_23_47-default
kernel-livepatch-SLE15-SP6_Update_10-debugsource
kernel-livepatch-6_4_0-150600_23_47-default-debuginfo
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-macros
kernel-default-base-debuginfo
ocfs2-kmp-default
ocfs2-kmp-default-debuginfo
kernel-default-base
gfs2-kmp-default
kernel-default-man
kernel-syms
kernel-default-kgraft
kernel-default-kgraft-devel
kernel-default-devel-debuginfo
kernel-devel
dlm-kmp-default-debuginfo
kernel-source
kernel-default
kernel-default-debugsource
kernel-default-debuginfo
cluster-md-kmp-default
kernel-default-devel
dlm-kmp-default
gfs2-kmp-default-debuginfo
cluster-md-kmp-default-debuginfo
linux (Ubuntu package)
linux-hwe-5.4 (Ubuntu package)
linux-iot (Ubuntu package)
linux-xilinx-zynqmp (Ubuntu package)
linux-ibm (Ubuntu package)
linux-ibm-5.4 (Ubuntu package)
linux-bluefield (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-raspi (Ubuntu package)
linux-raspi-5.4 (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle-5.4 (Ubuntu package)
linux-aws (Ubuntu package)
linux-aws-5.4 (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-hwe-5.15 (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-gke (Ubuntu package)
linux-gcp (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux (Debian package)
kernel-source-coco
kernel-devel-coco
reiserfs-kmp-coco-debuginfo
kernel-coco-vdso-debuginfo
kernel-coco-debuginfo
kernel-coco_debug-devel-debuginfo
kernel-coco_debug-debugsource
reiserfs-kmp-coco
kernel-coco-debugsource
kernel-coco_debug-devel
kernel-coco-devel
kernel-syms-coco
kernel-coco_debug-debuginfo
kernel-coco
kernel-coco_debug
kernel-syms-azure
gfs2-kmp-azure-debuginfo
kernel-azure-devel
kernel-devel-azure
gfs2-kmp-azure
kernel-azure-extra-debuginfo
cluster-md-kmp-azure
ocfs2-kmp-azure
reiserfs-kmp-azure
kernel-azure-debuginfo
kselftests-kmp-azure
ocfs2-kmp-azure-debuginfo
kernel-azure-optional-debuginfo
kernel-azure-extra
dlm-kmp-azure-debuginfo
kselftests-kmp-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-azure-optional
cluster-md-kmp-azure-debuginfo
kernel-source-azure
reiserfs-kmp-azure-debuginfo
kernel-azure-debugsource
dlm-kmp-azure
kernel-azure
kernel-azure-vdso-debuginfo
kernel-azure-vdso
kernel-rt-devel
kernel-rt-vdso
kernel-rt-devel-debuginfo
kernel-rt_debug-debuginfo
kernel-rt-extra
kernel-rt_debug-vdso
kernel-rt-optional
kernel-rt_debug-debugsource
reiserfs-kmp-rt-debuginfo
kernel-rt-vdso-debuginfo
kernel-rt_debug-devel-debuginfo
dlm-kmp-rt
kernel-rt-optional-debuginfo
dlm-kmp-rt-debuginfo
kselftests-kmp-rt-debuginfo
kernel-rt-debuginfo
kernel-rt_debug-vdso-debuginfo
kernel-rt-livepatch-devel
kernel-syms-rt
kselftests-kmp-rt
kernel-rt-debugsource
gfs2-kmp-rt
reiserfs-kmp-rt
kernel-rt_debug-devel
gfs2-kmp-rt-debuginfo
cluster-md-kmp-rt
cluster-md-kmp-rt-debuginfo
kernel-devel-rt
kernel-source-rt
ocfs2-kmp-rt
ocfs2-kmp-rt-debuginfo
kernel-rt_debug
kernel-rt
kernel-rt-extra-debuginfo
kernel-obs-qa
kernel-obs-build-debugsource
kernel-docs-html
kernel-docs
dtb-aarch64
kernel-obs-build
dtb-cavium
dtb-marvell
dtb-amazon
dtb-renesas
dtb-amd
dtb-hisilicon
dtb-allwinner
dtb-apm
dtb-xilinx
dtb-apple
dtb-rockchip
dtb-sprd
dtb-arm
dtb-freescale
dtb-mediatek
dtb-exynos
dtb-broadcom
dtb-altera
dtb-lg
dtb-amlogic
dtb-socionext
dtb-qcom
dtb-nvidia
kernel-debug-debuginfo
kernel-debug
kernel-debug-devel-debuginfo
kernel-debug-debugsource
kernel-debug-devel
dlm-kmp-64kb-debuginfo
kernel-kvmsmall-vdso
kernel-default-vdso-debuginfo
kernel-default-vdso
kernel-debug-vdso
kernel-debug-vdso-debuginfo
kernel-source-vanilla
kernel-64kb-optional
dlm-kmp-64kb
cluster-md-kmp-64kb
gfs2-kmp-64kb-debuginfo
ocfs2-kmp-64kb-debuginfo
ocfs2-kmp-64kb
reiserfs-kmp-64kb
kernel-64kb-debuginfo
kernel-64kb
gfs2-kmp-64kb
kernel-default-extra
kernel-default-livepatch
kernel-default-optional
kselftests-kmp-64kb-debuginfo
kernel-64kb-extra
kernel-default-livepatch-devel
kernel-kvmsmall
kernel-zfcpdump
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-64kb-devel
kselftests-kmp-64kb
kernel-default-extra-debuginfo
kernel-kvmsmall-devel
kernel-kvmsmall-debuginfo
kernel-kvmsmall-devel-debuginfo
reiserfs-kmp-64kb-debuginfo
kernel-kvmsmall-debugsource
reiserfs-kmp-default
kselftests-kmp-default
kernel-64kb-debugsource
kernel-kvmsmall-vdso-debuginfo
kselftests-kmp-default-debuginfo
reiserfs-kmp-default-debuginfo
kernel-default-optional-debuginfo
cluster-md-kmp-64kb-debuginfo
kernel-64kb-extra-debuginfo
kernel-64kb-devel-debuginfo
kernel-64kb-optional-debuginfo
kernel-default-base-rebuild
kernel
kernel-debuginfo
kernel-debugsource
kernel-headers
kernel-tools
perf-debuginfo
bpftool
kernel-tools-debuginfo
kernel-tools-devel
perf
bpftool-debuginfo
python3-perf-debuginfo
python3-perf
linux-aws-6.8 (Ubuntu package)
linux-oracle (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-lowlatency (Ubuntu package)
APEX Cloud Platform for Red Hat OpenShift

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

The vulnerability exists due to improper locking within the optee_supp_thrd_req() function in drivers/tee/optee/supp.c. A local user can perform a denial of service (DoS) attack.

Install update from vendor's website.

• https://git.kernel.org/stable/c/0180cf0373f84fff61b16f8c062553a13dd7cfca
• https://git.kernel.org/stable/c/21234efe2a8474a6d2d01ea9573319de7858ce44
• https://git.kernel.org/stable/c/3eb4911364c764572e9db4ab900a57689a54e8ce
• https://git.kernel.org/stable/c/70b0d6b0a199c5a3ee6c72f5e61681ed6f759612
• https://git.kernel.org/stable/c/c0a9a948159153be145f9471435695373904ee6d
• https://git.kernel.org/stable/c/d61cc1a435e6894bfb0dd3370c6f765d2d12825d
• https://git.kernel.org/stable/c/ec18520f5edc20a00c34a8c9fdd6507c355e880f
• https://git.kernel.org/stable/c/fd9d2d6124c293e40797a080adf8a9c237efd8b8
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.17