#VU106116 Improper locking in Linux kernel - CVE-2025-21876

Vulnerability identifier: #VU106116

Vulnerability risk: Low

CVSSv4.0: 4.3 [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

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

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.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://git.kernel.org/stable/c/4117c72938493a77ab53cc4b8284be8fb6ec8065
https://git.kernel.org/stable/c/b150654f74bf0df8e6a7936d5ec51400d9ec06d8
https://git.kernel.org/stable/c/c603ccbe91d189849e1439134598ec567088dcec

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.