---
id: CVE-2026-63857
title: 'net: airoha: Do not read uninitialized fragment address in airoha_dev_xmit()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: airoha: Do not read uninitialized fragment address in airoha_dev_xmit()

  The transmit loop in airoha_dev_xmit() reads fragment address and length
  during its final …
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 23020f04932701d5c8363e60756f12b43b8ed752 <
    dba5f4959653e4c212beb746594952e8645d1115
  - >-
    Linux >= 23020f04932701d5c8363e60756f12b43b8ed752 <
    f670fa4b19ceddc6d215dda4997888ccba9bbc61
  - >-
    Linux >= 23020f04932701d5c8363e60756f12b43b8ed752 <
    d78c8ab7bd84952e053d0c622b7fc1b4ad8a19a3
  - >-
    Linux >= 23020f04932701d5c8363e60756f12b43b8ed752 <
    bde34e84edc8b5571fbde7e941e175a4293ee1eb
  - Linux 6.11
published: '2026-07-19'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:42:41.508Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-63857'
references:
  - url: 'https://git.kernel.org/stable/c/dba5f4959653e4c212beb746594952e8645d1115'
  - url: 'https://git.kernel.org/stable/c/f670fa4b19ceddc6d215dda4997888ccba9bbc61'
  - url: 'https://git.kernel.org/stable/c/d78c8ab7bd84952e053d0c622b7fc1b4ad8a19a3'
  - url: 'https://git.kernel.org/stable/c/bde34e84edc8b5571fbde7e941e175a4293ee1eb'
tags:
  - cve.org
epss: 0.00649
epssPercentile: 0.50212
ingestedAt: '2026-10-21T12:48:53.614Z'
---

## Overview

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

net: airoha: Do not read uninitialized fragment address in airoha_dev_xmit()

The transmit loop in airoha_dev_xmit() reads fragment address and length
during its final iteration, when the loop index equals
skb_shinfo(skb)->nr_frags, at which point the fragment data is
uninitialized. While these values are never consumed, the read itself is
unsafe and may trigger a page fault. Fix this by avoiding the fragment
read on the last iteration.
Additionally, move the skb pointer from the first to the last used packet
descriptor, so that airoha_qdma_tx_napi_poll() defers freeing the skb
until the final descriptor is processed.

## Affected

- `Linux >= 23020f04932701d5c8363e60756f12b43b8ed752 < dba5f4959653e4c212beb746594952e8645d1115`
- `Linux >= 23020f04932701d5c8363e60756f12b43b8ed752 < f670fa4b19ceddc6d215dda4997888ccba9bbc61`
- `Linux >= 23020f04932701d5c8363e60756f12b43b8ed752 < d78c8ab7bd84952e053d0c622b7fc1b4ad8a19a3`
- `Linux >= 23020f04932701d5c8363e60756f12b43b8ed752 < bde34e84edc8b5571fbde7e941e175a4293ee1eb`
- `Linux 6.11`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.