Improper locking in Linux kernel - CVE-2026-23169

Vulnerability identifier: #VU122909

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-2026-23169

CWE-ID: CWE-667

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 improper locking within the __reset_counters() function in net/mptcp/pm_kernel.c. A local user can perform a denial of service (DoS) attack.

Linux kernel
Debian Linux
SUSE Linux Enterprise High Availability Extension 15
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 Desktop 15
Legacy Module
SUSE Linux Enterprise Live Patching
SUSE Real Time Module
Basesystem Module
Public Cloud Module
Development Tools Module
Ubuntu
openEuler
kernel-livepatch-SLE15-SP7-RT_Update_10-debugsource
kernel-livepatch-6_4_0-150700_7_34-rt
kernel-livepatch-6_4_0-150700_7_34-rt-debuginfo
kernel-livepatch-SLE15-SP7_Update_10-debugsource
kernel-livepatch-6_4_0-150700_53_34-default
kernel-livepatch-6_4_0-150700_53_34-default-debuginfo
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux (Debian package)
cluster-md-kmp-rt
ocfs2-kmp-rt-debuginfo
kernel-syms-rt
kernel-rt
kernel-source-rt
kernel-devel-rt
gfs2-kmp-rt
cluster-md-kmp-rt-debuginfo
kernel-rt-debuginfo
dlm-kmp-rt
dlm-kmp-rt-debuginfo
kernel-rt-devel
ocfs2-kmp-rt
kernel-rt-debugsource
kernel-rt-devel-debuginfo
gfs2-kmp-rt-debuginfo
gfs2-kmp-default
dlm-kmp-default
cluster-md-kmp-default-debuginfo
gfs2-kmp-default-debuginfo
kernel-default
kernel-default-livepatch
kernel-64kb-debuginfo
kernel-64kb-devel-debuginfo
kernel-64kb-debugsource
kernel-64kb-devel
kernel-64kb
kernel-source
kernel-default-devel-debuginfo
kernel-default-debuginfo
kernel-default-devel
kernel-devel
kernel-macros
kernel-zfcpdump
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-docs
kernel-obs-build
kernel-obs-build-debugsource
kernel-syms
kernel-default-debugsource
reiserfs-kmp-default
reiserfs-kmp-default-debuginfo
kernel-azure
kernel-azure-debugsource
kernel-azure-debuginfo
kernel-azure-devel
kernel-azure-devel-debuginfo
ocfs2-kmp-default-debuginfo
cluster-md-kmp-default
dlm-kmp-default-debuginfo
ocfs2-kmp-default
kernel-default-extra-debuginfo
kernel-default-extra
kernel-default-livepatch-devel
kernel-default-base
kernel-headers
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
python3-perf-debuginfo
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
kernel
kernel-extra-modules
linux-hwe-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-azure-fde-6.17 (Ubuntu package)
linux-gcp-6.17 (Ubuntu package)
linux-oracle-6.17 (Ubuntu package)
linux-azure-6.17 (Ubuntu package)
linux-oem-6.17 (Ubuntu package)
linux-nvidia-6.17 (Ubuntu package)

Install update from vendor's repository.

kernel-livepatch-SLE15-SP7-RT_Update_10-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_34-rt - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_34-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7_Update_10-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_34-default - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_34-default-debuginfo - update to 1-150700.15.3.1
linux (Ubuntu package) - addressed in versions 5.15.0.184.155, 5.15.0-184.194, 5.15.0-184.194~20.04.1, 5.15.0.186.166, 5.15.0-186.196, 5.15.0-186.196~20.04.1, 5.15.0.1075.78, 5.15.0-1075.79, 5.15.0.1095.94, 5.15.0-1095.103, 5.15.0.1104.100, 5.15.0-1104.109, 5.15.0.1108.107, 5.15.0-1108.114, 5.15.0.1111.115, 5.15.0-1111.120+fips1, 5.15.0.1112.102, 5.15.0.1112.109, 5.15.0-1112.122, 5.15.0-1112.122+fips1, 6.8.0-134.134, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61+fips1, 6.8.0-1058.61~22.04.1, 6.8.0-1060.61, 6.8.0-1060.63+fips1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69, 6.8.0-1063.69+fips1, 6.8.1-1055.56, 6.8.1-1055.56~22.04.1
linux-aws (Ubuntu package) - addressed in versions 5.15.0.186.109, 5.15.0-186.196+fips1, 5.15.0.1106.103, 5.15.0-1106.110, 5.15.0.1107.107, 5.15.0-1107.108, 5.15.0.1112.108, 5.15.0.1112.115, 5.15.0-1112.119, 5.15.0-1112.119+fips1, 5.15.0-1112.119~20.04.1
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1053.53, 5.15.0.1053.55, 5.15.0.1064.64, 5.15.0-1064.66, 6.8.0-1029.30
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1064.66~20.04.1
linux-intel-iot-realtime (Ubuntu package) - addressed in versions 5.15.0-1104.106, 5.15.0.1104.108, 5.15.0-1107.113~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1106.110~20.04.1
linux-intel-iotg (Ubuntu package) - addressed in versions 5.15.0.1107.106, 5.15.0-1107.113
linux-azure (Ubuntu package) - addressed in versions 5.15.0.1109.105, 5.15.0-1109.115, 5.15.0.1117.115, 5.15.0-1117.126, 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-5.15 (Ubuntu package) - addressed in versions 5.15.0-1109.115~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1112.122~20.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1117.102, 5.15.0-1117.126+fips1, 6.8.0-134.134+fips1, 6.8.0-1062.69+fips1
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1117.126, 6.8.0-1062.69
linux (Debian package) - addressed in versions 6.1.164-1, 6.12.73-1
cluster-md-kmp-rt - update to 6.4.0-150700.7.34.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.34.1
kernel-syms-rt - update to 6.4.0-150700.7.34.1
kernel-rt - update to 6.4.0-150700.7.34.1
kernel-source-rt - update to 6.4.0-150700.7.34.1
kernel-devel-rt - update to 6.4.0-150700.7.34.1
gfs2-kmp-rt - update to 6.4.0-150700.7.34.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.34.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.34.1
dlm-kmp-rt - update to 6.4.0-150700.7.34.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.34.1
kernel-rt-devel - update to 6.4.0-150700.7.34.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.34.1
kernel-rt-debugsource - update to 6.4.0-150700.7.34.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.34.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.34.1
gfs2-kmp-default - update to 6.4.0-150700.53.34.1
dlm-kmp-default - update to 6.4.0-150700.53.34.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.34.1
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.34.1
kernel-default - update to 6.4.0-150700.53.34.1
kernel-default-livepatch - update to 6.4.0-150700.53.34.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.34.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.34.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.34.1
kernel-64kb-devel - update to 6.4.0-150700.53.34.1
kernel-64kb - update to 6.4.0-150700.53.34.1
kernel-source - update to 6.4.0-150700.53.34.1
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.34.1
kernel-default-debuginfo - update to 6.4.0-150700.53.34.1
kernel-default-devel - update to 6.4.0-150700.53.34.1
kernel-devel - update to 6.4.0-150700.53.34.1
kernel-macros - update to 6.4.0-150700.53.34.1
kernel-zfcpdump - update to 6.4.0-150700.53.34.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.34.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.34.1
kernel-docs - update to 6.4.0-150700.53.34.1
kernel-obs-build - update to 6.4.0-150700.53.34.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.34.1
kernel-syms - update to 6.4.0-150700.53.34.1
kernel-default-debugsource - update to 6.4.0-150700.53.34.1
reiserfs-kmp-default - update to 6.4.0-150700.53.34.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.34.1
kernel-azure - update to 6.4.0-150700.53.34.1
kernel-azure-debugsource - update to 6.4.0-150700.53.34.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.34.1
kernel-azure-devel - update to 6.4.0-150700.53.34.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.34.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.34.1
cluster-md-kmp-default - update to 6.4.0-150700.53.34.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.34.1
ocfs2-kmp-default - update to 6.4.0-150700.53.34.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.34.1
kernel-default-extra - update to 6.4.0-150700.53.34.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.34.1
kernel-default-base - update to 6.4.0-150700.53.34.1.150700.17.23.1
kernel-headers - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
bpftool - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
bpftool-debuginfo - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
kernel-debuginfo - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
kernel-debugsource - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
kernel-devel - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
python3-perf-debuginfo - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
kernel-source - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
kernel-tools - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
kernel-tools-debuginfo - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
kernel-tools-devel - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
perf - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
perf-debuginfo - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
python3-perf - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
kernel - addressed in versions 6.6.0-144.0.0.139, 6.6.0-145.0.0.128, 6.6.0-145.0.0.141
kernel-extra-modules - update to 6.6.0-145.0.0.141
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1045.48, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61.1, 6.8.0-1058.64, 6.8.0-1060.61~22.04.1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69~22.04.1
linux-raspi (Ubuntu package) - update to 6.8.0-1060.64
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2049.50
linux-azure-fde-6.17 (Ubuntu package) - update to 6.17.0-1018.18~24.04.1
linux-gcp-6.17 (Ubuntu package) - addressed in versions 6.17.0-1018.20~24.04.1, 6.17.0-1021.24~24.04.1
linux-oracle-6.17 (Ubuntu package) - addressed in versions 6.17.0-1019.19~24.04.3, 6.17.0-1019.19~24.04.3+1
linux-azure-6.17 (Ubuntu package) - update to 6.17.0-1021.21~24.04.1
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1030.30
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1031.31

• https://git.kernel.org/stable/c/1f1b9523527df02685dde603f20ff6e603d8e4a1
• https://git.kernel.org/stable/c/e2a9eeb69f7d4ca4cf4c70463af77664fdb6ab1d

• Improper locking in Linux kernel mptcp
• Debian update for linux
• Debian update for linux
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• openEuler 24.03 LTS SP1 update for kernel
• openEuler 24.03 LTS SP2 update for kernel
• openEuler 24.03 LTS update for kernel
• Ubuntu update for linux
• Ubuntu update for linux-nvidia-tegra
• Ubuntu update for linux-aws-6.8
• Ubuntu update for linux-raspi-realtime
• Ubuntu update for linux-raspi
• Ubuntu update for linux-azure-fips
• Ubuntu update for linux-gcp-6.17
• Ubuntu update for linux-nvidia-tegra-5.15
• Ubuntu update for linux
• Ubuntu update for linux-oem-6.17
• Ubuntu update for linux-ibm-5.15
• Ubuntu update for linux-nvidia-tegra
• Ubuntu update for linux-aws
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-fde-6.8
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-fde-6.17
• Ubuntu update for linux-azure-6.17
• Ubuntu update for linux-azure-5.15
• Ubuntu update for linux-hwe-6.8
• Ubuntu update for linux-oracle-6.17
• Ubuntu update for linux-azure-fips
• Ubuntu update for linux-intel-iot-realtime
• Ubuntu update for linux-intel-iotg
• Ubuntu update for linux-nvidia-6.17
• Ubuntu update for linux-gcp-5.15