CVE-2025-40042
Description
A race condition flaw was found in the Linux kernel's tracing subsystem during kprobe initialization. The race occurs between kprobe activation and perf_events initialization on different CPUs. When CPU0 enables kprobe functionality via class->reg() but before perf_events is fully assigned, CPU1 can trigger the kprobe and attempt to access the perf_events pointer while it is still NULL. This results in a NULL pointer dereference in kprobe_perf_func(), causing a kernel crash. A local user with the ability to use tracing/kprobe functionality could exploit this to cause a denial of service.
Statement
This vulnerability requires local access and the ability to use kernel tracing features (kprobes/perf). The race window is narrow but reproducible under specific conditions. Exploitation results in a kernel crash requiring a system 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 | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Modify Application Data; Alter Execution Logic
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