CVE-2025-39697
Description
A flaw use after free in the Linux kernel NFS functionality was found in the way connected user sends malicious data to the server. A remote user could use this flaw to crash the system.
Statement
A race condition in the NFS write path allowed a request to be removed after it was checked but before the page-group lock was taken. The fix acquires the page-group lock earlier and holds it across request removal, preventing use-after-state races. This can be triggered by a client with write access to an export and may lead to a kernel crash (remote DoS). This race condition is difficult to trigger in practice, as it requires several conditions to align (concurrent write activity and timing), and there is no evidence of remote control over memory contents. Therefore the most likely outcome is a denial of service (Availability: High), with Confidentiality and Integrity unaffected.
Mitigation
To mitigate this issue, prevent module nfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 4.7 | 7.8 |
| Attack Vector | Network | Local | Local |
| Attack Complexity | Low | High | Low |
| Privileges Required | None | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | High |
| Integrity Impact | None | None | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:H/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:U/C:H/I:H/A:H
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