CVE-2025-71078
Description
A Segment Lookaside Buffer (SLB) multi-hit error vulnerability was found in the Linux kernel's PowerPC 64-bit hash MMU implementation. When a process migrates between CPUs without triggering switch_mmu_context() (because prev and next mm_struct are the same), the hardware SLB and software preload cache can become desynchronized. This leads to duplicate SLB entries when the evicted entry is later reloaded, triggering a fatal SLB multi-hit machine check exception.
Statement
This vulnerability affects PowerPC 64-bit systems using the hash MMU (not radix). The race requires specific process migration patterns across CPUs during context switches. When triggered, the SLB multi-hit error causes a machine check exception that typically results in system crash. The issue is specific to PowerPC server hardware.
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 | 7.8 | 7.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | High | High |
| Integrity Impact | None | High | High |
| 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:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality
Technical Impact: Modify Application Data; Read Application Data
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