Improper locking in Linux kernel - CVE-2025-71126

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Main Vulnerability Database Vulnerabilities #VU121505

Improper locking in Linux kernel - CVE-2025-71126

Published: January 14, 2026


Vulnerability identifier: #VU121505
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-2025-71126
CWE-ID: CWE-667
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

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


Affected software

Linux kernel
Debian Linux
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
Legacy Module
Public Cloud Module
Basesystem Module
SUSE Real Time Module
SUSE Linux Enterprise Live Patching
Development Tools Module
Ubuntu
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 (Debian package)
ocfs2-kmp-rt-debuginfo
kernel-syms-rt
kernel-rt-debuginfo
gfs2-kmp-rt
kernel-rt
kernel-source-rt
kernel-devel-rt
cluster-md-kmp-rt-debuginfo
dlm-kmp-rt
dlm-kmp-rt-debuginfo
kernel-rt-debugsource
cluster-md-kmp-rt
gfs2-kmp-rt-debuginfo
ocfs2-kmp-rt
kernel-rt-devel
kernel-rt-devel-debuginfo
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
gfs2-kmp-default-debuginfo
gfs2-kmp-default
dlm-kmp-default
cluster-md-kmp-default-debuginfo
kernel-default-extra-debuginfo
kernel-default-extra
kernel-default-livepatch
ocfs2-kmp-default
kernel-default-livepatch-devel
kernel-syms
kernel-source
kernel-64kb
kernel-64kb-devel
kernel-64kb-debugsource
kernel-64kb-devel-debuginfo
kernel-64kb-debuginfo
kernel-default
kernel-default-debugsource
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-default-base
linux (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-xilinx (Ubuntu package)
linux-oracle (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-lowlatency (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime (Ubuntu package)
linux-aws (Ubuntu package)
linux-realtime-6.17 (Ubuntu package)
linux-gcp (Ubuntu package)
linux-raspi (Ubuntu package)

How to mitigate CVE-2025-71126

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 (Debian package) - addressed in versions 6.1.162-1, 6.12.69-1
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-debuginfo - update to 6.4.0-150700.7.34.1
gfs2-kmp-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
cluster-md-kmp-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-debugsource - update to 6.4.0-150700.7.34.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.34.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.34.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.34.1
kernel-rt-devel - update to 6.4.0-150700.7.34.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.34.1
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
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.34.1
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
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 - update to 6.4.0-150700.53.34.1
ocfs2-kmp-default - update to 6.4.0-150700.53.34.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.34.1
kernel-syms - update to 6.4.0-150700.53.34.1
kernel-source - update to 6.4.0-150700.53.34.1
kernel-64kb - update to 6.4.0-150700.53.34.1
kernel-64kb-devel - update to 6.4.0-150700.53.34.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.34.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.34.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.34.1
kernel-default - update to 6.4.0-150700.53.34.1
kernel-default-debugsource - 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-default-base - update to 6.4.0-150700.53.34.1.150700.17.23.1
linux (Ubuntu package) - addressed in versions 6.8.0-110.110, 6.8.0-110.110.1, 6.8.0-110.110.1~22.04.1, 6.8.0-1037.40, 6.8.0-1050.56, 6.8.0-1051.51, 6.8.0-1052.55~22.04.1, 6.8.0-1054.57, 6.17.0-22.22, 6.17.0-1010.11
linux-aws-fips (Ubuntu package) - addressed in versions 6.8.0-110.110+fips2, 6.8.0-1052.55+fips1, 6.8.0-1054.57+fips1
linux-hwe-6.8 (Ubuntu package) - addressed in versions 6.8.0-110.110~22.04.1, 6.8.0-1051.51~22.04.1, 6.8.0-1052.56
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1022.22
linux-xilinx (Ubuntu package) - update to 6.8.0-1029.30
linux-oracle (Ubuntu package) - addressed in versions 6.8.0-1049.50, 6.8.0-1049.50~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1051.54, 6.8.0-1051.54~22.04.1
linux-nvidia-lowlatency (Ubuntu package) - update to 6.8.0-1051.54.1
linux-gcp-6.8 (Ubuntu package) - update to 6.8.0-1054.57~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1054.60, 6.17.0-1013.13, 6.17.0-1013.13~24.04.1, 6.17.0-1020.20
linux-azure-fips (Ubuntu package) - update to 6.8.0-1054.60+fips1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2042.43
linux-realtime (Ubuntu package) - update to 6.8.1-1047.48
linux-aws (Ubuntu package) - addressed in versions 6.17.0-22.22~24.04.1, 6.17.0-1011.11, 6.17.0-1011.11~24.04.1, 6.17.0-1012.12, 6.17.0-1012.12~24.04.1
linux-realtime-6.17 (Ubuntu package) - update to 6.17.0-1010.11~24.04.1
linux-gcp (Ubuntu package) - addressed in versions 6.17.0-1012.12, 6.17.0-1012.12~24.04.1
linux-raspi (Ubuntu package) - update to 6.17.0-1014.14

External References

Related Security Bulletins