---
id: CVE-2026-64280
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region()

  afu_ioctl_dma_map() accepts a 64-bit length from userspace via
  DFL_FPGA_PORT_DMA_MAP ioctl without a…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region()

  afu_ioctl_dma_map() accepts a 64-bit length from userspace via
  DFL_FPGA_PORT_DMA_MAP ioctl without a…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'
published: '2026-07-25'
updated: '2026-07-27'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64280'
references:
  - url: 'https://git.kernel.org/stable/c/59070040fd12e0b78d7b4d341d9f9a183237c5ff'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fb2c0eab51ae5b02d2bae7d67c2cfbec39b57231'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fc3b071a7c8dc0f5d56defddf6e6fd5aaa3e1e27'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00169
epssPercentile: 0.06592
ingestedAt: '2026-07-27T06:16:50.015Z'
---

## Overview

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

fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region()

afu_ioctl_dma_map() accepts a 64-bit length from userspace via
DFL_FPGA_PORT_DMA_MAP ioctl without an upper bound check. The value
is passed to afu_dma_pin_pages() where npages is derived as
length >> PAGE_SHIFT and passed to pin_user_pages_fast() which takes
int nr_pages, causing implicit truncation if length is very large.

Validate map.length at the ioctl entry point before calling
afu_dma_map_region(), rejecting values whose page count exceeds
INT_MAX.

## Remediation

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