Type conversion in Linux kernel - CVE-2026-23352

 

Type conversion in Linux kernel - CVE-2026-23352

Published: March 25, 2026


Vulnerability identifier: #VU124495
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-23352
CWE-ID: CWE-704
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to improper memory management in the EFI boot services memory release mechanism when processing memory map initialization during system boot. A local attacker can trigger the early release of boot services memory before deferred memory map initialization is complete, leading to unfreed memory pages and a memory leak.

The issue specifically occurs on systems with CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, where memblock_free_late() skips uninitialized pages, resulting in a significant memory leak—up to approximately 140MB on constrained systems like EC2 t3a.nano instances with only 512MB RAM.


Affected software

Linux kernel
Debian Linux
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Live Patching
SUSE Real Time Module
Public Cloud Module
Legacy Module
Development Tools Module
Basesystem Module
Ubuntu
openEuler
kernel-livepatch-6_4_0-150700_7_78-rt-debuginfo
kernel-livepatch-6_4_0-150700_7_78-rt
kernel-livepatch-SLE15-SP7-RT_Update_21-debugsource
kernel-livepatch-6_4_0-150700_53_84-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_22-debugsource
kernel-livepatch-6_4_0-150700_53_84-default
bpftool
kernel
python3-perf-debuginfo
python3-perf
perf-debuginfo
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
perf
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-rt
ocfs2-kmp-rt-debuginfo
cluster-md-kmp-rt-debuginfo
kernel-rt-debuginfo
kernel-rt-devel-debuginfo
kernel-rt-devel
dlm-kmp-rt
kernel-syms-rt
kernel-rt-debugsource
cluster-md-kmp-rt
dlm-kmp-rt-debuginfo
gfs2-kmp-rt
gfs2-kmp-rt-debuginfo
ocfs2-kmp-rt
kernel-source-rt
kernel-devel-rt
kernel-64kb-devel
kernel-default-devel-debuginfo
kernel-default-livepatch
kernel-default-livepatch-devel
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-obs-build-debugsource
kernel-obs-build
kernel-syms
kernel-docs
kernel-default-devel
kernel-64kb-debugsource
kernel-64kb-devel-debuginfo
kernel-64kb-debuginfo
kernel-64kb
kernel-zfcpdump-debuginfo
kernel-zfcpdump-debugsource
kernel-zfcpdump
kernel-macros
kernel-default
ocfs2-kmp-default
gfs2-kmp-default
dlm-kmp-default
gfs2-kmp-default-debuginfo
cluster-md-kmp-default
kernel-default-debugsource
dlm-kmp-default-debuginfo
kernel-default-debuginfo
ocfs2-kmp-default-debuginfo
kernel-default-extra-debuginfo
kernel-default-extra
kernel-azure-devel-debuginfo
kernel-azure-debuginfo
kernel-azure-devel
kernel-azure-debugsource
kernel-azure
cluster-md-kmp-default-debuginfo
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-raspi (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux (Debian package)
linux-hwe-6.8 (Ubuntu package)
linux-fips (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-gcp-fips (Ubuntu package)

How to mitigate CVE-2026-23352

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-livepatch-6_4_0-150700_7_78-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_78-rt - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_21-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_84-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_22-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_84-default - update to 1-150700.15.3.1
bpftool - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
python3-perf-debuginfo - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
python3-perf - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
perf-debuginfo - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel-tools-devel - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel-tools-debuginfo - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel-tools - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel-source - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
perf - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
bpftool-debuginfo - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel-debuginfo - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel-debugsource - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel-devel - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel-headers - addressed in versions 5.10.0-307.0.0.210, 6.6.0-145.0.13.139, 6.6.0-145.1.12.150
kernel-rt - update to 6.4.0-150700.7.78.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-devel - update to 6.4.0-150700.7.78.1
dlm-kmp-rt - update to 6.4.0-150700.7.78.1
kernel-syms-rt - update to 6.4.0-150700.7.78.1
kernel-rt-debugsource - update to 6.4.0-150700.7.78.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.78.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
gfs2-kmp-rt - update to 6.4.0-150700.7.78.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.78.1
kernel-source-rt - update to 6.4.0-150700.7.78.1
kernel-devel-rt - update to 6.4.0-150700.7.78.1
kernel-64kb-devel - update to 6.4.0-150700.53.84.1
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-livepatch - update to 6.4.0-150700.53.84.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.84.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
reiserfs-kmp-default - update to 6.4.0-150700.53.84.1
kernel-source - update to 6.4.0-150700.53.84.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.84.1
kernel-obs-build - update to 6.4.0-150700.53.84.1
kernel-syms - update to 6.4.0-150700.53.84.1
kernel-docs - update to 6.4.0-150700.53.84.1
kernel-default-devel - update to 6.4.0-150700.53.84.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.84.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb - update to 6.4.0-150700.53.84.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.84.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.84.1
kernel-zfcpdump - update to 6.4.0-150700.53.84.1
kernel-macros - update to 6.4.0-150700.53.84.1
kernel-devel - update to 6.4.0-150700.53.84.1
kernel-default - update to 6.4.0-150700.53.84.1
ocfs2-kmp-default - update to 6.4.0-150700.53.84.1
gfs2-kmp-default - update to 6.4.0-150700.53.84.1
dlm-kmp-default - update to 6.4.0-150700.53.84.1
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
cluster-md-kmp-default - update to 6.4.0-150700.53.84.1
kernel-default-debugsource - update to 6.4.0-150700.53.84.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-debuginfo - update to 6.4.0-150700.53.84.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-extra - update to 6.4.0-150700.53.84.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.84.1
kernel-azure-devel - update to 6.4.0-150700.53.84.1
kernel-azure-debugsource - update to 6.4.0-150700.53.84.1
kernel-azure - update to 6.4.0-150700.53.84.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-base - update to 6.4.0-150700.53.84.1.150700.17.47.1
linux (Ubuntu package) - addressed in versions 5.15.0-184.194~20.04.1, 5.15.0-184.194, 5.15.0-186.196~20.04.1, 5.15.0-186.196, 5.15.0-1075.79, 5.15.0-1095.103, 5.15.0-1104.109, 5.15.0-1108.114, 5.15.0-1111.120+fips1, 5.15.0-1112.122, 5.15.0-1112.122+fips1, 5.15.0.184.155, 5.15.0.186.166, 5.15.0.1075.78, 5.15.0.1095.94, 5.15.0.1104.100, 5.15.0.1108.107, 5.15.0.1111.115, 5.15.0.1112.102, 5.15.0.1112.109, 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72~22.04.1, 6.8.0-1064.72, 6.8.1-1056.57~22.04.2, 6.8.1-1056.57
linux-aws (Ubuntu package) - addressed in versions 5.15.0-186.196+fips1, 5.15.0-1106.110, 5.15.0-1107.108, 5.15.0-1112.119~20.04.1, 5.15.0-1112.119, 5.15.0-1112.119+fips1, 5.15.0.186.109, 5.15.0.1106.103, 5.15.0.1107.107, 5.15.0.1112.108, 5.15.0.1112.115, 6.8.0-1061.64+1
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1053.53, 5.15.0-1064.66, 5.15.0.1053.55, 5.15.0.1064.64
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, 5.15.0-1107.113~20.04.1, 5.15.0.1104.108
linux-raspi (Ubuntu package) - addressed in versions 5.15.0-1106.109, 5.15.0.1106.104, 6.8.0-1061.65, 6.8.0-2050.52
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1106.110~20.04.1
linux-intel-iotg (Ubuntu package) - addressed in versions 5.15.0-1107.113, 5.15.0.1107.106
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-azure (Ubuntu package) - addressed in versions 5.15.0-1109.115, 5.15.0-1117.126, 5.15.0.1109.105, 5.15.0.1117.115, 6.8.0-1063.71~22.04.1, 6.8.0-1063.71
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1112.122~20.04.1
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1117.126, 6.8.0-1062.69
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0-1117.126+fips1, 5.15.0.1117.102, 6.8.0-1063.71+fips2
linux (Debian package) - addressed in versions 6.1.170-1, 6.12.85-1
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2~22.04.1, 6.8.0-136.136.2, 6.8.0-1058.61
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62~22.04.1, 6.8.0-1061.62
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62~22.04.1, 6.8.0-1059.62, 6.8.0-1059.62.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64~22.04.1, 6.8.0-1061.64+fips1
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

External References

Related Security Bulletins