CVE-2020-11669
Description
A flaw was found in the way Linux kernel running on the Power9 processor saves and restores its registers while going in and coming out of an idle state. The issue occurs when a guest kernel has Kernel Userspace Address Protection (KUAP) feature enabled. The idle_book3s function does not save and restore the Authority Mask Register (AMR), Authority Mask Override Register (AMOR) and User Authority Mask Override Register (UAMOR). A guest user may use this flaw to render the host system unusable resulting in DoS issue.
Statement
This issue does not affect the versions of the kernel package as shipped with the Red Hat Enterprise Linux 5, 6, 7, 8 and Red Hat Enterprise MRG 2.
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 | 5.5 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
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
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Unexpected State; Alter Execution Logic
This weakness could place the system in a state that could lead unexpected logic to be executed or other unintended behaviors.
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