---
id: "CVE-2026-98492"
kind: "vulnerability"
aliases: ["CVE-2026-98492"]
title: "Linux kernel: macb network driver leaks DMA memory on allocation errors"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["arm", "embedded", "linux-kernel", "package"]
not_affected_if: ["no-macb-hardware"]
published_at: "2026-10-18T16:17:00+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T05:25:41+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98492", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Linux kernel: macb network driver leaks DMA memory on allocation errors

In the Linux kernel's Cadence MACB Ethernet driver, error paths in macb_alloc() fail to free DMA-coherent buffers, so memory is leaked when Tx or Rx buffer allocation fails or crosses a 4G boundary. The sources describe a resource leak, not code execution or data exposure.

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

## How to check

- unknown

## Fix

- Update to a Linux kernel release that includes the upstream commit 'net: macb: fix dma_alloc_coherent() leak on macb_alloc() error paths' (version unknown from sources)

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98492

## From the sources

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

net: macb: fix dma_alloc_coherent() leak on macb_alloc() error paths

Fix 3 leaks in macb_alloc() error paths:
- Tx buffer allocated but crossing a 4G boundary: Tx leaked.
- Rx buffer allocation fails: Tx leaked.
- Rx buffer allocated but crossing a 4G boundary: Tx & Rx leaked.

This is because our error handling calls macb_free(bp) which in turn
frees the buffers stored in bp->queues[0], but nothing has been stored
in there. Fix by storing allocated buffers into bp->queues[0] ASAP.

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