CVE-2025-71269
Description
A resource accounting flaw was found in the Linux kernel's btrfs filesystem. When creating an inline extent fails with -ENOSPC, the code falls back to the normal COW (copy-on-write) path. However, it incorrectly frees the reserved qgroup data even though the data will still be written via the fallback path. This causes qgroup accounting to become inconsistent, potentially allowing data writes to exceed quota limits.
Statement
This flaw affects btrfs filesystems using qgroups for quota management. The incorrect qgroup reservation handling occurs in an error recovery path when inline extent creation fails due to space pressure. While this can cause quota accounting inconsistencies, it requires specific conditions (qgroups enabled, ENOSPC during inline extent creation) and does not directly lead to code execution or data corruption.
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)
Integrity,Confidentiality,Availability,Other
Technical Impact: DoS: Crash, Exit, or Restart; Execute Unauthorized Code or Commands; Modify Memory; Other
Depending on the locking being used, an unlock operation might not have any adverse effects. When effects exist, the most common consequence will be a corruption of the state of the product, possibly leading to a crash or exit; depending on the implementation of the unlocking, memory corruption or code execution could occur.
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