CVE-2025-71161
Description
A denial-of-service vulnerability was found in the Linux kernel's dm-verity device mapper target. The recursive forward error correction (FEC) implementation allows up to 253^4 (approximately 4 billion) iterations due to nested recursion in fec_read_bufs() and verity_hash_for_block(). A specially crafted dm-verity image can trigger this worst-case behavior, causing the udev-worker process to become stuck in uninterruptible sleep state.
Statement
This vulnerability was discovered by the Red Hat QE team who created a dm-verity image that triggers the maximum recursion depth. The resulting denial of service causes system processes to hang in D state, affecting system responsiveness. Additionally, the recursive FEC is fundamentally broken as the shared fio->bufs buffer gets overwritten during recursion. Local access to create or mount dm-verity images is required.
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 | 5.5 | 5.5 | 7.5 |
| Attack Vector | Local | Local | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Amplification
An infinite loop will cause unexpected consumption of resources, such as CPU cycles or memory. The software's operation may slow down, or cause a long time to respond.
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