CVE-2025-21876
Description
A flaw was found in the Linux kernel's IOMMU (Input/Output Memory Management Unit) subsystem. A local attacker could potentially trigger a kernel warning related to improper locking mechanisms when handling IOMMU fault interrupts. This issue could lead to a system crash, resulting in a Denial of Service (DoS).
Mitigation
To mitigate this issue, the `intel_iommu` kernel module can be prevented from loading. This may impact systems utilizing Intel VT-d for device passthrough or other IOMMU-dependent features.
Create a file `/etc/modprobe.d/disable-intel-iommu.conf` with the following content:
blacklist intel_iommuAfter creating the file, regenerate the initramfs and reboot the system for the changes to take effect.
install intel_iommu /bin/true
bashWarning: Disabling the `intel_iommu` module may affect system functionality, especially in virtualized environments or when using hardware requiring IOMMU.
dracut -f -v
reboot
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.3 | 5.5 | 8.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Changed |
| Confidentiality | None | None | High |
| Integrity Impact | None | None | High |
| Availability Impact | Low | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
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