CVE-2026-23135
Description
A flaw was found in the Linux kernel's ath12k wifi driver. A local attacker could exploit this vulnerability by triggering the device driver teardown path. The driver incorrectly passes aligned memory addresses to dma_free_coherent() instead of the original unaligned addresses during cleanup. This improper memory deallocation can lead to memory leaks, data corruption, or kernel crashes, ultimately resulting in a denial of service.
Statement
A bug exists in the ath12k copy engine ring tear down path where dma_free_coherent is called with pointers that do not match those returned by dma_alloc_coherent. The driver allocates descriptor rings using dma_alloc_coherent and stores the original CPU and DMA addresses in base_addr_owner_space_unaligned and base_addr_ce_space_unaligned. It then derives aligned addresses for runtime use. During cleanup, the driver incorrectly passed the aligned CPU and DMA addresses to dma_free_coherent instead of the original unaligned values. The DMA API requires that the exact addresses returned by dma_alloc_coherent be used for freeing. Freeing with a shifted aligned pointer can result in invalid free behavior such as freeing the wrong address, memory leaks of DMA coherent memory, allocator metadata corruption, warnings, or kernel crashes. Because this occurs in a device driver teardown path, the most realistic impact is denial of service through kernel instability.
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 | 6.1 | 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 | Low | 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:L/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,Availability,Confidentiality
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; Execute Unauthorized Code or Commands
This weakness may result in the corruption of memory, and perhaps instructions, possibly leading to a crash. If the corrupted memory can be effectively controlled, it may be possible to execute arbitrary code.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
