CVE-2024-56636
Description
A flaw was found in the Geneve tunneling implementation of the Linux kernel. In the geneve_xmit_skb() function, the kernel incorrectly assumes that the MAC header is set, leading to invalid memory access when it is not. This issue can be triggered when sending packets through a Geneve tunnel, resulting in warnings or crashes. A local attacker could exploit this by crafting specific network traffic to cause a denial of service, affecting system availability.
Statement
The bug could happen when local user sending packet using geneve virtual interfaces that provide Layer 2 Networks over Layer 3 Networks. It doesn't lead to kernel crash, but handled as hardware driver failure that leads to Linux kernel tainted state. The security impact is limited, because no known vector of attack apart from deny of service.
Mitigation
To mitigate this issue, prevent module geneve 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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.7 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | 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:H/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: Varies by Context; Unexpected State
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