NULL Pointer Dereference in Linux kernel - CVE-2026-23277

Vulnerability identifier: #VU124173

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-23277

CWE-ID: CWE-476

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a NULL pointer dereference in the teql network scheduler component when handling packet transmission through a gretap tunnel configured as a TEQL slave. A remote attacker can send a specially crafted network request to trigger a NULL pointer dereference in iptunnel_xmit, leading to a kernel page fault and system crash.

Exploitation does not require authentication or elevated privileges. The issue arises because the skb->dev field is not updated to the slave device before transmission, causing iptunnel_xmit_stats to access uninitialized tstats via a NULL pointer.

Linux kernel
Debian Linux
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
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
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Development Tools Module
Basesystem Module
SUSE Real Time Module
Ubuntu
openEuler
kgraft-patch-4_12_14-122_299-default
kernel-livepatch-SLE15-SP7-RT_Update_11-debugsource
kernel-livepatch-6_4_0-150700_7_37-rt
kernel-livepatch-6_4_0-150700_7_37-rt-debuginfo
kernel-livepatch-6_4_0-150700_53_37-default-debuginfo
kernel-livepatch-6_4_0-150700_53_37-default
kernel-livepatch-SLE15-SP7_Update_11-debugsource
dlm-kmp-default-debuginfo
kernel-default-kgraft
gfs2-kmp-default-debuginfo
kernel-default-kgraft-devel
kernel-default-devel-debuginfo
kernel-default-man
kernel-devel
kernel-macros
kernel-source
kernel-default
dlm-kmp-default
kernel-default-debuginfo
gfs2-kmp-default
ocfs2-kmp-default
cluster-md-kmp-default
cluster-md-kmp-default-debuginfo
kernel-syms
kernel-default-debugsource
kernel-default-base-debuginfo
ocfs2-kmp-default-debuginfo
kernel-default-devel
kernel-default-base
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)
kernel-syms-rt
ocfs2-kmp-rt-debuginfo
cluster-md-kmp-rt-debuginfo
cluster-md-kmp-rt
gfs2-kmp-rt
kernel-rt-debuginfo
gfs2-kmp-rt-debuginfo
kernel-devel-rt
kernel-source-rt
kernel-rt
kernel-rt-debugsource
ocfs2-kmp-rt
kernel-rt-devel
kernel-rt-devel-debuginfo
dlm-kmp-rt-debuginfo
dlm-kmp-rt
kernel-64kb-devel
kernel-64kb-debugsource
kernel-64kb-debuginfo
kernel-64kb-devel-debuginfo
kernel-64kb
kernel-azure-devel
kernel-zfcpdump
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-docs
kernel-obs-build
kernel-obs-build-debugsource
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-azure
kernel-azure-devel-debuginfo
kernel-azure-debuginfo
kernel-azure-debugsource
kernel-default-extra-debuginfo
kernel-default-extra
kernel-default-livepatch-devel
kernel-default-livepatch
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-headers
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo
kernel-tools
kernel-extra-modules
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-gcp-fips (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_299-default - update to 1-8.3.1
kernel-livepatch-SLE15-SP7-RT_Update_11-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_37-rt - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_37-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_37-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_37-default - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_11-debugsource - update to 1-150700.15.3.1
dlm-kmp-default-debuginfo - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-default-kgraft - update to 4.12.14-122.299.1
gfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-default-kgraft-devel - update to 4.12.14-122.299.1
kernel-default-devel-debuginfo - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-default-man - update to 4.12.14-122.299.1
kernel-devel - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-macros - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-source - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-default - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
dlm-kmp-default - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-default-debuginfo - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
gfs2-kmp-default - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
ocfs2-kmp-default - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
cluster-md-kmp-default - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
cluster-md-kmp-default-debuginfo - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-syms - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-default-debugsource - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-default-base-debuginfo - update to 4.12.14-122.299.1
ocfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-default-devel - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1
kernel-default-base - addressed in versions 4.12.14-122.299.1, 6.4.0-150700.53.37.1.150700.17.25.1
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, 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2
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, 6.8.0-1061.64+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
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, 6.8.0-1063.71+fips2
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1117.126, 6.8.0-1062.69
linux (Debian package) - addressed in versions 6.1.170-1, 6.12.85-1
kernel-syms-rt - update to 6.4.0-150700.7.37.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.37.2
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.37.2
cluster-md-kmp-rt - update to 6.4.0-150700.7.37.2
gfs2-kmp-rt - update to 6.4.0-150700.7.37.2
kernel-rt-debuginfo - update to 6.4.0-150700.7.37.2
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.37.2
kernel-devel-rt - update to 6.4.0-150700.7.37.2
kernel-source-rt - update to 6.4.0-150700.7.37.2
kernel-rt - update to 6.4.0-150700.7.37.2
kernel-rt-debugsource - update to 6.4.0-150700.7.37.2
ocfs2-kmp-rt - update to 6.4.0-150700.7.37.2
kernel-rt-devel - update to 6.4.0-150700.7.37.2
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.37.2
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.37.2
dlm-kmp-rt - update to 6.4.0-150700.7.37.2
kernel-64kb-devel - update to 6.4.0-150700.53.37.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.37.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.37.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.37.1
kernel-64kb - update to 6.4.0-150700.53.37.1
kernel-azure-devel - update to 6.4.0-150700.53.37.1
kernel-zfcpdump - update to 6.4.0-150700.53.37.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.37.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.37.1
kernel-docs - update to 6.4.0-150700.53.37.1
kernel-obs-build - update to 6.4.0-150700.53.37.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.37.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.37.1
reiserfs-kmp-default - update to 6.4.0-150700.53.37.1
kernel-azure - update to 6.4.0-150700.53.37.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.37.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.37.1
kernel-azure-debugsource - update to 6.4.0-150700.53.37.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.37.1
kernel-default-extra - update to 6.4.0-150700.53.37.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.37.1
kernel-default-livepatch - update to 6.4.0-150700.53.37.1
kernel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debugsource - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-headers - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-source - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-extra-modules - update to 6.6.0-145.0.2.143
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1061.65, 6.8.0-2050.52
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1

• https://git.kernel.org/stable/c/0bad9c86edd22dec4df83c2b29872d66fd8a2ff4
• https://git.kernel.org/stable/c/0cc0c2e661af418bbf7074179ea5cfffc0a5c466
• https://git.kernel.org/stable/c/21ea283c2750c8307aa35ee832b0951cc993c27d

• NULL Pointer Dereference in Linux kernel sched
• openEuler 24.03 LTS SP2 update for kernel
• openEuler 24.03 LTS SP1 update for kernel
• openEuler 24.03 LTS update for kernel
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• Debian update for linux
• Debian update for linux
• Ubuntu update for linux
• Ubuntu update for linux-gcp-fips
• Ubuntu update for linux-nvidia-tegra-5.15
• Ubuntu update for linux
• Ubuntu update for linux-oracle-6.8
• Ubuntu update for linux-fips
• Ubuntu update for linux-ibm-5.15
• Ubuntu update for linux-nvidia-tegra
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-fde-6.8
• Ubuntu update for linux-azure-fips
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-azure-5.15
• Ubuntu update for linux-hwe-6.8
• Ubuntu update for linux-aws-6.8
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure-fips
• Ubuntu update for linux-intel-iot-realtime
• Ubuntu update for linux-intel-iotg
• Ubuntu update for linux-raspi
• Ubuntu update for linux-gcp-5.15