---
id: CVE-2026-68401
title: 'firmware: arm_ffa: Fix out-of-bound writes in ffa_setup_and_transmit()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  firmware: arm_ffa: Fix out-of-bound writes in ffa_setup_and_transmit()

  Sashiko (locally) reports multiple out-of-bound issues in
  ffa_setup_and_transmit:
  1) Writing ep_…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 <
    d312a71b19bb83803c8d1372bc042bd36db657f7
  - >-
    Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 <
    00bef9d0f9e787f56ff4699d3b577983ff8b7f24
  - >-
    Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 <
    cf5708c9d78c98214c62b1e5d049cd527a543b8e
  - >-
    Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 <
    27abdaf0c5c89b06694e4c3d8318e8d6a60c1d1b
  - >-
    Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 <
    3383ffb7ef937317361713ffcc21921a7848511a
  - Linux 28ebfb74fbf513e0c7cd2674d8c2400ee0220d18
  - Linux 22157f74458106c5900dbd938eb44623c22d97a0
  - Linux b77ec23b6df41c48e88735230e11caec56163630
  - Linux >= 5.15.114 < 5.16
  - Linux >= 6.1.31 < 6.2
  - Linux >= 6.3.5 < 6.4
  - Linux 6.4
published: '2026-08-10'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:43:59.902Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-68401'
references:
  - url: 'https://git.kernel.org/stable/c/d312a71b19bb83803c8d1372bc042bd36db657f7'
  - url: 'https://git.kernel.org/stable/c/00bef9d0f9e787f56ff4699d3b577983ff8b7f24'
  - url: 'https://git.kernel.org/stable/c/cf5708c9d78c98214c62b1e5d049cd527a543b8e'
  - url: 'https://git.kernel.org/stable/c/27abdaf0c5c89b06694e4c3d8318e8d6a60c1d1b'
  - url: 'https://git.kernel.org/stable/c/3383ffb7ef937317361713ffcc21921a7848511a'
tags:
  - cve.org
epss: 0.00136
epssPercentile: 0.02752
ingestedAt: '2026-10-21T12:48:53.599Z'
---

## Overview

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

firmware: arm_ffa: Fix out-of-bound writes in ffa_setup_and_transmit()

Sashiko (locally) reports multiple out-of-bound issues in
ffa_setup_and_transmit:
1) Writing ep_mem_access->reserved can write out of bounds for FFA
   versions < 1.2 as ffa_emad_size_get() returns 16 bytes in that case
   while reserved has an offset of 24.
   Instead of zeroing fields, memset the struct to zero first based on
   the FFA version.

2) Make sure there is enough size to write constituents.

While at it, convert the only sizeof() in the driver that uses a
type instead of variable.

## Affected

- `Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 < d312a71b19bb83803c8d1372bc042bd36db657f7`
- `Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 < 00bef9d0f9e787f56ff4699d3b577983ff8b7f24`
- `Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 < cf5708c9d78c98214c62b1e5d049cd527a543b8e`
- `Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 < 27abdaf0c5c89b06694e4c3d8318e8d6a60c1d1b`
- `Linux >= 111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 < 3383ffb7ef937317361713ffcc21921a7848511a`
- `Linux 28ebfb74fbf513e0c7cd2674d8c2400ee0220d18`
- `Linux 22157f74458106c5900dbd938eb44623c22d97a0`
- `Linux b77ec23b6df41c48e88735230e11caec56163630`
- `Linux >= 5.15.114 < 5.16`
- `Linux >= 6.1.31 < 6.2`
- `Linux >= 6.3.5 < 6.4`
- `Linux 6.4`

## Remediation

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