Improper input validation in Linux kernel - CVE-2026-31420

Vulnerability identifier: #VU125860

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-2026-31420

CWE-ID: CWE-20

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper input validation in br_mrp_start_test(), br_mrp_start_in_test(), and br_mrp_start_in_test_parse() when processing user-supplied netlink attributes. A local user can supply a zero interval value to cause a denial of service.

A zero interval causes delayed work to be rescheduled with no delay, creating a tight loop that allocates and transmits MRP test frames until system memory is exhausted and the kernel panics via OOM deadlock.

Linux kernel
Debian Linux
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
Legacy Module
SUSE Linux Enterprise Live Patching
Public Cloud Module
Development Tools Module
Basesystem Module
SUSE Real Time Module
openEuler
kernel-livepatch-6_4_0-150700_7_54-rt
kernel-livepatch-SLE15-SP7-RT_Update_15-debugsource
kernel-livepatch-6_4_0-150700_7_54-rt-debuginfo
kernel-livepatch-6_4_0-150700_53_55-default
kernel-livepatch-6_4_0-150700_53_55-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_15-debugsource
kernel-rt
dlm-kmp-rt
kernel-source-rt
kernel-devel-rt
gfs2-kmp-rt-debuginfo
cluster-md-kmp-rt
ocfs2-kmp-rt
kernel-syms-rt
gfs2-kmp-rt
kernel-rt-debugsource
cluster-md-kmp-rt-debuginfo
kernel-rt-debuginfo
kernel-rt-devel-debuginfo
dlm-kmp-rt-debuginfo
kernel-rt-devel
ocfs2-kmp-rt-debuginfo
kernel-64kb-devel
kernel-source
kernel-obs-build-debugsource
kernel-obs-build
kernel-syms
kernel-docs
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
kernel-macros
kernel-devel
kernel-default-devel
kernel-default-devel-debuginfo
kernel-64kb-debuginfo
kernel-default
kernel-64kb-debugsource
kernel-64kb-devel-debuginfo
kernel-64kb
cluster-md-kmp-default
kernel-default-debuginfo
ocfs2-kmp-default-debuginfo
dlm-kmp-default-debuginfo
kernel-default-debugsource
gfs2-kmp-default
gfs2-kmp-default-debuginfo
dlm-kmp-default
cluster-md-kmp-default-debuginfo
ocfs2-kmp-default
kernel-default-livepatch-devel
kernel-default-livepatch
kernel-default-extra
kernel-default-extra-debuginfo
kernel-azure-devel
kernel-azure-devel-debuginfo
kernel-azure-debuginfo
kernel-azure-debugsource
kernel-azure
reiserfs-kmp-default
reiserfs-kmp-default-debuginfo
kernel-default-base
perf-debuginfo
kernel-debugsource
kernel-headers
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
python3-perf
python3-perf-debuginfo
kernel-debuginfo
bpftool-debuginfo
bpftool
kernel
kernel-extra-modules
linux (Debian package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-livepatch-6_4_0-150700_7_54-rt - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_15-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_54-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_55-default - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_55-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_15-debugsource - update to 1-150700.15.3.1
kernel-rt - update to 6.4.0-150700.7.54.1
dlm-kmp-rt - update to 6.4.0-150700.7.54.1
kernel-source-rt - update to 6.4.0-150700.7.54.1
kernel-devel-rt - update to 6.4.0-150700.7.54.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.54.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.54.1
kernel-syms-rt - update to 6.4.0-150700.7.54.1
gfs2-kmp-rt - update to 6.4.0-150700.7.54.1
kernel-rt-debugsource - update to 6.4.0-150700.7.54.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.54.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-devel - update to 6.4.0-150700.7.54.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-64kb-devel - update to 6.4.0-150700.53.55.1
kernel-source - update to 6.4.0-150700.53.55.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.55.1
kernel-obs-build - update to 6.4.0-150700.53.55.1
kernel-syms - update to 6.4.0-150700.53.55.1
kernel-docs - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.55.1
kernel-zfcpdump - update to 6.4.0-150700.53.55.1
kernel-macros - update to 6.4.0-150700.53.55.1
kernel-devel - update to 6.4.0-150700.53.55.1
kernel-default-devel - update to 6.4.0-150700.53.55.1
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.55.1
kernel-default - update to 6.4.0-150700.53.55.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.55.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-64kb - update to 6.4.0-150700.53.55.1
cluster-md-kmp-default - update to 6.4.0-150700.53.55.1
kernel-default-debuginfo - update to 6.4.0-150700.53.55.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
kernel-default-debugsource - update to 6.4.0-150700.53.55.1
gfs2-kmp-default - update to 6.4.0-150700.53.55.1
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
dlm-kmp-default - update to 6.4.0-150700.53.55.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
ocfs2-kmp-default - update to 6.4.0-150700.53.55.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.55.1
kernel-default-livepatch - update to 6.4.0-150700.53.55.1
kernel-default-extra - update to 6.4.0-150700.53.55.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-devel - update to 6.4.0-150700.53.55.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-debugsource - update to 6.4.0-150700.53.55.1
kernel-azure - update to 6.4.0-150700.53.55.1
reiserfs-kmp-default - update to 6.4.0-150700.53.55.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
kernel-default-base - update to 6.4.0-150700.53.55.1.150700.17.33.1
perf-debuginfo - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel-debugsource - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel-devel - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel-headers - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel-source - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel-tools - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel-tools-debuginfo - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel-tools-devel - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
perf - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
python3-perf - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
python3-perf-debuginfo - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel-debuginfo - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
bpftool-debuginfo - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
bpftool - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel - addressed in versions 6.6.0-145.0.9.136, 6.6.0-145.0.9.140, 6.6.0-145.0.9.148
kernel-extra-modules - update to 6.6.0-145.0.9.140
linux (Debian package) - update to 6.12.94-1

• https://git.kernel.org/stable/c/c9bc352f716d1bebfe43354bce539ec2d0223b30
• https://git.kernel.org/stable/c/fa6e24963342de4370e3a3c9af41e38277b74cf3

• Improper input validation in Linux kernel bridge
• openEuler 24.03 LTS SP1 update for kernel
• openEuler 24.03 LTS update for kernel
• openEuler 24.03 LTS SP3 update for kernel
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• Debian update for linux