Improper locking in Linux kernel - CVE-2025-21875

Vulnerability identifier: #VU106115

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-2025-21875

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

Affected software:
Linux kernel
Debian Linux
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 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
SUSE Linux Enterprise Live Patching
Public Cloud Module
Confidential Computing Module
Basesystem Module
Development Tools Module
Legacy Module
openSUSE Leap
Ubuntu
openEuler
kernel-livepatch-SLE15-SP6-RT_Update_11-debugsource
kernel-livepatch-6_4_0-150600_10_39-rt-debuginfo
kernel-livepatch-6_4_0-150600_10_39-rt
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
linux (Ubuntu package)
linux-hwe-5.15 (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-xilinx-zynqmp (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-gke (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-gcp (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux (Debian package)
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
kernel-coco-vdso-debuginfo
reiserfs-kmp-coco-debuginfo
kernel-devel-coco
kernel-source-coco
cluster-md-kmp-azure
kernel-azure
kernel-azure-optional
kernel-azure-debugsource
reiserfs-kmp-azure-debuginfo
gfs2-kmp-azure-debuginfo
kselftests-kmp-azure-debuginfo
kernel-azure-devel-debuginfo
kselftests-kmp-azure
reiserfs-kmp-azure
kernel-syms-azure
gfs2-kmp-azure
ocfs2-kmp-azure-debuginfo
kernel-azure-debuginfo
dlm-kmp-azure-debuginfo
kernel-azure-vdso-debuginfo
kernel-azure-vdso
kernel-devel-azure
kernel-source-azure
kernel-azure-extra-debuginfo
dlm-kmp-azure
kernel-azure-extra
kernel-azure-devel
cluster-md-kmp-azure-debuginfo
kernel-azure-optional-debuginfo
ocfs2-kmp-azure
dlm-kmp-rt-debuginfo
kernel-rt-debugsource
cluster-md-kmp-rt
kernel-rt-extra
dlm-kmp-rt
kernel-rt-vdso
kernel-rt_debug-devel
kselftests-kmp-rt
kernel-rt_debug-debugsource
kernel-devel-rt
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
cluster-md-kmp-rt-debuginfo
gfs2-kmp-rt-debuginfo
ocfs2-kmp-rt-debuginfo
kselftests-kmp-rt-debuginfo
ocfs2-kmp-rt
kernel-rt_debug
kernel-rt
kernel-source-rt
kernel-rt-devel
kernel-rt-extra-debuginfo
kernel-syms-rt
kernel-rt_debug-debuginfo
kernel-rt_debug-vdso
kernel-rt_debug-devel-debuginfo
kernel-rt-debuginfo
kernel-rt-optional
kernel-default-devel-debuginfo
ocfs2-kmp-default
kernel-default-livepatch-devel
kernel-default-livepatch
kernel-default-extra-debuginfo
kernel-default-extra
ocfs2-kmp-default-debuginfo
gfs2-kmp-default-debuginfo
dlm-kmp-default
cluster-md-kmp-default-debuginfo
kernel-obs-build
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-64kb-devel
kernel-source
kernel-syms
kernel-obs-build-debugsource
kernel-docs
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
kernel-macros
kernel-devel
kernel-default-devel
kernel-64kb-devel-debuginfo
kernel-64kb-debuginfo
kernel-64kb-debugsource
kernel-64kb
kernel-default-base
bpftool-debuginfo
python3-perf
kernel-debuginfo
kernel-debugsource
kernel-headers
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
bpftool
kernel
python3-perf-debuginfo
linux-hwe-6.8 (Ubuntu package)
linux-azure-nvidia (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)

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

The vulnerability exists due to improper locking within the mptcp_nl_remove_subflow_and_signal_addr() function in net/mptcp/pm_netlink.c. A local user can perform a denial of service (DoS) attack.

Install update from vendor's website.

• https://git.kernel.org/stable/c/2c3de6dff4373f1036e003f49a32629359530bdb
• https://git.kernel.org/stable/c/4124b782ec2b1e2e490cf0bbf10f53dfd3479890
• https://git.kernel.org/stable/c/494ec285535632732eaa5786297a9ae4f731b5ff
• https://git.kernel.org/stable/c/7cca31035c05819643ffb5d7518e9a331b3f6651
• https://git.kernel.org/stable/c/8116fb4acd5d3f06cd37f84887dbe962b6703b1c
• https://git.kernel.org/stable/c/a05da2be18aae7e82572f8d795f41bb49f5dfc7d
• https://git.kernel.org/stable/c/f865c24bc55158313d5779fc81116023a6940ca3
• https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.235
• https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.179
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.1.130
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.18
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.6
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.14
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.6.81