Improper locking in Linux kernel - CVE-2026-64428

Vulnerability identifier: #VU139539

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-2026-64428

CWE-ID: CWE-667

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 lock type selection in the sch irq startup path when starting up a requested irq on PREEMPT_RT systems. A local user can request a threaded irq that reaches sch_irq_unmask() and sch_irq_mask_unmask() to cause a denial of service.

The issue occurs because the path is not sleepable, but a regular spinlock_t becomes a sleeping lock on PREEMPT_RT.

Linux kernel
Debian Linux
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Real Time Module
Legacy Module
Public Cloud Module
SUSE Linux Enterprise Live Patching
Development Tools Module
Basesystem Module
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-realtime (Ubuntu package)
linux-fips (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-gke (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
kernel-livepatch-6_4_0-150700_7_81-rt
kernel-livepatch-SLE15-SP7-RT_Update_22-debugsource
kernel-livepatch-6_4_0-150700_7_81-rt-debuginfo
kernel-livepatch-SLE15-SP7_Update_23-debugsource
kernel-livepatch-6_4_0-150700_53_87-default-debuginfo
kernel-livepatch-6_4_0-150700_53_87-default
dlm-kmp-rt
dlm-kmp-rt-debuginfo
kernel-syms-rt
gfs2-kmp-rt-debuginfo
cluster-md-kmp-rt
kernel-rt-debuginfo
ocfs2-kmp-rt-debuginfo
cluster-md-kmp-rt-debuginfo
kernel-rt-devel-debuginfo
kernel-rt-debugsource
ocfs2-kmp-rt
gfs2-kmp-rt
kernel-rt-devel
kernel-devel-rt
kernel-source-rt
kernel-rt
kernel-syms
kernel-obs-build-debugsource
kernel-obs-build
kernel-source
reiserfs-kmp-default
cluster-md-kmp-default-debuginfo
gfs2-kmp-default
ocfs2-kmp-default-debuginfo
dlm-kmp-default-debuginfo
kernel-default-debugsource
cluster-md-kmp-default
kernel-default-debuginfo
ocfs2-kmp-default
kernel-docs
kernel-64kb-debugsource
kernel-64kb-debuginfo
kernel-default-extra-debuginfo
kernel-default-extra
kernel-azure-devel
kernel-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-azure-debugsource
kernel-azure
kernel-default-livepatch
kernel-default-livepatch-devel
reiserfs-kmp-default-debuginfo
kernel-64kb-devel-debuginfo
kernel-64kb-devel
kernel-64kb
kernel-zfcpdump-debuginfo
kernel-zfcpdump-debugsource
kernel-zfcpdump
kernel-macros
kernel-devel
kernel-default-devel-debuginfo
kernel-default-devel
kernel-default
gfs2-kmp-default-debuginfo
dlm-kmp-default
kernel-default-base
linux-nvidia (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux (Debian package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux (Ubuntu package) - addressed in versions 5.15.0-195.205~20.04.1, 5.15.0-195.205, 5.15.0-198.208~20.04.1, 5.15.0-198.208+fips1, 5.15.0-1080.84, 5.15.0-1100.108, 5.15.0-1109.111, 5.15.0-1109.114, 5.15.0-1111.115~20.04.1, 5.15.0-1111.115, 5.15.0-1112.118~20.04.1, 5.15.0-1112.118, 5.15.0-1113.119, 5.15.0-1114.120, 5.15.0-1116.125~20.04.1, 5.15.0-1117.124~20.04.1, 5.15.0-1117.124, 5.15.0-1117.124+fips1, 5.15.0-1122.131~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1123.132, 5.15.0-1123.132+fips1, 5.15.0.195.160, 5.15.0.195.205~20.04.1, 5.15.0.198.114, 5.15.0.198.171, 5.15.0.198.208~20.04.1, 5.15.0.1080.83~20.04.1, 5.15.0.1100.99, 5.15.0.1109.105, 5.15.0.1109.113, 5.15.0.1111.108, 5.15.0.1111.115~20.04.1, 5.15.0.1112.111, 5.15.0.1112.118~20.04.1, 5.15.0.1113.112, 5.15.0.1114.110, 5.15.0.1116.120, 5.15.0.1117.113, 5.15.0.1117.120, 5.15.0.1117.124~20.04.1, 5.15.0.1122.131~20.04.1, 5.15.0.1123.107, 5.15.0.1123.121, 5.15.0.1123.132~20.04.1, 6.8.0-147.147, 7.0.0-31.31~24.04.1, 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1012.12
linux-lowlatency (Ubuntu package) - update to 6.8.0-147.147.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1071.79, 7.0.0-1011.11, 7.0.0-1014.14
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1118.128, 5.15.0-1118.128+fips1, 5.15.0.1118.107, 5.15.0.1118.115, 6.8.0-1071.79
linux-aws (Ubuntu package) - update to 6.8.0-1067.70
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1067.68, 7.0.0-1013.13
linux-oracle (Ubuntu package) - update to 6.8.0-1064.67
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1122.131, 5.15.0.1122.131, 6.8.0-1069.76
linux-realtime (Ubuntu package) - update to 6.8.1-1062.63
linux-fips (Ubuntu package) - update to 6.8.0-147.147+fips1
linux-gkeop (Ubuntu package) - update to 6.8.0-1052.56
linux-gke (Ubuntu package) - update to 6.8.0-1066.74
linux-azure-fips (Ubuntu package) - update to 6.8.0-1071.79+fips1
linux-aws-fips (Ubuntu package) - update to 6.8.0-1067.70+fips1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1071.79+fips1
kernel-livepatch-6_4_0-150700_7_81-rt - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_22-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_81-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7_Update_23-debugsource - update to 1-150700.15.3.2
kernel-livepatch-6_4_0-150700_53_87-default-debuginfo - update to 1-150700.15.3.2
kernel-livepatch-6_4_0-150700_53_87-default - update to 1-150700.15.3.2
dlm-kmp-rt - update to 6.4.0-150700.7.81.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.81.1
kernel-syms-rt - update to 6.4.0-150700.7.81.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.81.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.81.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.81.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.81.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.81.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.81.1
kernel-rt-debugsource - update to 6.4.0-150700.7.81.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.81.1
gfs2-kmp-rt - update to 6.4.0-150700.7.81.1
kernel-rt-devel - update to 6.4.0-150700.7.81.1
kernel-devel-rt - update to 6.4.0-150700.7.81.1
kernel-source-rt - update to 6.4.0-150700.7.81.1
kernel-rt - update to 6.4.0-150700.7.81.1
kernel-syms - update to 6.4.0-150700.53.87.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.87.2
kernel-obs-build - update to 6.4.0-150700.53.87.2
kernel-source - update to 6.4.0-150700.53.87.3
reiserfs-kmp-default - update to 6.4.0-150700.53.87.3
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.87.3
gfs2-kmp-default - update to 6.4.0-150700.53.87.3
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.87.3
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.87.3
kernel-default-debugsource - update to 6.4.0-150700.53.87.3
cluster-md-kmp-default - update to 6.4.0-150700.53.87.3
kernel-default-debuginfo - update to 6.4.0-150700.53.87.3
ocfs2-kmp-default - update to 6.4.0-150700.53.87.3
kernel-docs - update to 6.4.0-150700.53.87.3
kernel-64kb-debugsource - update to 6.4.0-150700.53.87.3
kernel-64kb-debuginfo - update to 6.4.0-150700.53.87.3
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.87.3
kernel-default-extra - update to 6.4.0-150700.53.87.3
kernel-azure-devel - update to 6.4.0-150700.53.87.3
kernel-azure-debuginfo - update to 6.4.0-150700.53.87.3
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.87.3
kernel-azure-debugsource - update to 6.4.0-150700.53.87.3
kernel-azure - update to 6.4.0-150700.53.87.3
kernel-default-livepatch - update to 6.4.0-150700.53.87.3
kernel-default-livepatch-devel - update to 6.4.0-150700.53.87.3
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.87.3
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.87.3
kernel-64kb-devel - update to 6.4.0-150700.53.87.3
kernel-64kb - update to 6.4.0-150700.53.87.3
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.87.3
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.87.3
kernel-zfcpdump - update to 6.4.0-150700.53.87.3
kernel-macros - update to 6.4.0-150700.53.87.3
kernel-devel - update to 6.4.0-150700.53.87.3
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.87.3
kernel-default-devel - update to 6.4.0-150700.53.87.3
kernel-default - update to 6.4.0-150700.53.87.3
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.87.3
dlm-kmp-default - update to 6.4.0-150700.53.87.3
kernel-default-base - update to 6.4.0-150700.53.87.3.150700.17.49.2
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112, 7.0.0-1018.18
linux-oracle-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.120~20.04.1, 5.15.0.1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1118.128~20.04.1, 5.15.0.1118.128~20.04.1
linux (Debian package) - update to 6.12.100-1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18

• https://git.kernel.org/stable/c/286533cb14a3c8a8bd39ff64ea2fc8e1aa0f638b
• https://git.kernel.org/stable/c/3b1aa05ec27eeccc889ecaa3f2d9baa9f453e50d
• https://git.kernel.org/stable/c/41cad91a09d69e8fff4e936db29b1054b4e9f9f7
• https://git.kernel.org/stable/c/4508366ab7dd0c2917a51a9c2e23cc1b9d35157a
• https://git.kernel.org/stable/c/4f03a15cc73c83740fc355ee22b336492d17b4da
• https://git.kernel.org/stable/c/7a550256d68bbdfa0903ab1c4595c04a6815493a
• https://git.kernel.org/stable/c/a235cec779bb39ec8f961a935b28a2ce278c6c64

• Improper locking in Linux kernel gpio driver
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-ibm
• Ubuntu update for linux-raspi
• Ubuntu update for linux-nvidia-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-gcp
• Ubuntu update for linux-gcp-5.15
• Ubuntu update for linux-oracle-5.15
• Ubuntu update for linux
• Ubuntu update for linux, linux-aws, linux-aws-fips and more
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• Ubuntu update for linux-azure, linux-azure-fde, linux-azure-fips
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx