Improper locking in Linux kernel - CVE-2025-21876

Vulnerability identifier: #VU106116

CSH Severity: Low

CVSS v4.0: 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/E:U/U:Clear

CVE-ID: CVE-2025-21876

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

Affected software:
Linux kernel
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
Public Cloud Module
Confidential Computing Module
SUSE Linux Enterprise Live Patching
SUSE Real Time Module
Legacy Module
Development Tools Module
Basesystem Module
openSUSE Leap
Ubuntu
APEX Cloud Platform for Microsoft Azure
kernel-livepatch-SLE15-SP6-RT_Update_10-debugsource
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kernel-livepatch-6_4_0-150600_23_47-default
kernel-livepatch-SLE15-SP6_Update_10-debugsource
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kernel-default-base-rebuild
kernel-default-base
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-aws (Ubuntu package)

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

The vulnerability exists due to improper locking within the intel_iommu_init() function in drivers/iommu/intel/iommu.c, within the enable_drhd_fault_handling() function in drivers/iommu/intel/dmar.c. A local user can perform a denial of service (DoS) attack.

Install update from vendor's website.

• https://git.kernel.org/stable/c/4117c72938493a77ab53cc4b8284be8fb6ec8065
• https://git.kernel.org/stable/c/b150654f74bf0df8e6a7936d5ec51400d9ec06d8
• https://git.kernel.org/stable/c/c603ccbe91d189849e1439134598ec567088dcec
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.6