CVE-2022-45869
説明
A flaw was found in the Linux kernel in the KVM. A race condition in direct_page_fault allows guest OS users to cause a denial of service (host OS crash or host OS memory corruption) when nested virtualization and the TDP MMU are enabled.
詳細
The nested virtualization feature is not enabled by default up to Red Hat Enterprise Linux 8.4. Most importantly, Red Hat currently provides nested virtualization only as a Technology Preview and is therefore unsupported for production use. For additional details, please see https://access.redhat.com/solutions/21101 and https://access.redhat.com/support/offerings/techpreview.
軽減策
This vulnerability can be mitigated by disabling the nested virtualization feature.
For Intel:
# modprobe -r kvm_intel
# modprobe kvm_intel nested=0
For AMD:
# modprobe -r kvm_amd
# modprobe kvm_amd nested=0
CVSS (Common Vulnerability Scoring System) のスコアの詳細
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 スコアの内訳
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| ベーススコア | 5.5 | 5.5 | 5.5 |
| 攻撃ベクトル | Local | Local | Local |
| 攻撃の複雑さ | Low | Low | Low |
| 必要な権限 | Low | Low | Low |
| ユーザー関与レベル | None | None | None |
| 範囲 | Unchanged | Unchanged | Unchanged |
| 機密性 | None | None | None |
| 完全性への影響 | None | None | None |
| 可用性への影響 | High | High | High |
ベクトル
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:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
脆弱性の原因 (CWE) の理解
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When a race condition makes it possible to bypass a resource cleanup routine or trigger multiple initialization routines, it may lead to resource exhaustion.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Instability
When a race condition allows multiple control flows to access a resource simultaneously, it might lead the product(s) into unexpected states, possibly resulting in a crash.
Confidentiality,Integrity
Technical Impact: Read Files or Directories; Read Application Data
When a race condition is combined with predictable resource names and loose permissions, it may be possible for an attacker to overwrite or access confidential data (CWE-59).
Access Control
Technical Impact: Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity; Bypass Protection Mechanism
This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider.
よくある質問
Not sure what something means? Check out our Security Glossary.
エラータ通知の受信を希望しますか? こちらで登録してください。
