---
id: CVE-2025-21734
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  misc: fastrpc: Fix copy buffer page size

  For non-registered buffer, fastrpc driver copies the buffer and
  pass it to the remote subsystem
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  misc: fastrpc: Fix copy buffer page size

  For non-registered buffer, fastrpc driver copies the buffer and
  pass it to the remote subsystem. There is a problem with curre…
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'
cwe:
  - CWE-787
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.2, < 6.1.129'
  - 'linux_kernel >= 6.2, < 6.6.78'
  - 'linux_kernel >= 6.7, < 6.12.14'
  - 'linux_kernel >= 6.13, < 6.13.3'
patched:
  - linux_kernel 6.13.3
published: '2025-02-27'
updated: '2026-07-30'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-21734'
references:
  - url: 'https://git.kernel.org/stable/c/24a79c6bc8de763f7c50f4f84f8b0c183bc25a51'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c0464bad0e85fcd5d47e4297d1e410097c979e55'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c3f7161123fcbdc64e90119ccce292d8b66281c4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c56ba3ea8e3c9a69a992aad18f7a65e43e51d623'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e966eae72762ecfdbdb82627e2cda48845b9dd66'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00206
epssPercentile: 0.09328
ingestedAt: '2026-07-30T06:53:09.541Z'
---

## Overview

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

misc: fastrpc: Fix copy buffer page size

For non-registered buffer, fastrpc driver copies the buffer and
pass it to the remote subsystem. There is a problem with current
implementation of page size calculation which is not considering
the offset in the calculation. This might lead to passing of
improper and out-of-bounds page size which could result in
memory issue. Calculate page start and page end using the offset
adjusted address instead of absolute address.

## Affected

- `linux_kernel >= 5.2, < 6.1.129`
- `linux_kernel >= 6.2, < 6.6.78`
- `linux_kernel >= 6.7, < 6.12.14`
- `linux_kernel >= 6.13, < 6.13.3`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.13.3`