---
id: "CVE-2026-98486"
kind: "vulnerability"
aliases: ["CVE-2026-98486"]
title: "Linux kernel: ENA driver leaks a DMA buffer when probe fails"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["aws-ec2", "ena-driver", "infrastructure", "linux-kernel"]
not_affected_if: ["no-ena-hardware", "probe-succeeds"]
published_at: "2026-10-18T16:16:59+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T05:25:46+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98486", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Linux kernel: ENA driver leaks a DMA buffer when probe fails

The Amazon ENA network driver in the Linux kernel does not free a coherent DMA buffer used for MMIO register reads when device probe fails partway through. The leak is a resource exhaustion issue found by code inspection, and the sources describe no code execution or data exposure.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the running kernel with `uname -r` and compare it against the fixed kernel builds in the upstream stable tree or distribution advisories
- Check whether the ENA driver is loaded with `lsmod | grep ena`

## Fix

- Update to a kernel build that includes the upstream commit titled 'net: ena: fix MMIO read buffer leak on probe failure' (version unknown from the sources)
- Reboot after the kernel update so the fixed driver is active

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98486

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

net: ena: fix MMIO read buffer leak on probe failure

ena_device_init() initializes the MMIO read mechanism with
ena_com_mmio_reg_read_request_init(), which allocates a coherent DMA
buffer for MMIO read responses.

The normal removal path releases this buffer through
ena_com_mmio_reg_read_request_destroy(). However, if ena_probe() fails
after ena_device_init() succeeds, the error path destroys the admin
resources and eventually frees ena_dev without destroying the MMIO read
request, leaving the coherent DMA buffer allocated.

Call ena_com_mmio_reg_read_request_destroy() in the probe error path
before releasing the remaining device resources.

This issue was found by manual code inspection.

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