---
id: CVE-2025-21724
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index()

  Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index()
  where shifting…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index()

  Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index()
  where shifting…
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 >= 6.1, < 6.1.129'
  - 'linux_kernel >= 6.2, < 6.6.76'
  - 'linux_kernel >= 6.7, < 6.12.13'
  - 'linux_kernel >= 6.13, < 6.13.2'
patched:
  - linux_kernel 6.13.2
published: '2025-02-27'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T02:17:30.170'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-21724'
references:
  - url: 'https://git.kernel.org/stable/c/38ac76fc06bc6826a3e4b12a98efbe98432380a9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/44d9c94b7a3f29a3e07c4753603a35e9b28842a3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b1f8453b8ff1ab79a03820ef608256c499769cb6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d5d33f01b86af44b23eea61ee309e4ef22c0cdfe'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e24c1551059268b37f6f40639883eafb281b8b9c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-082556.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-784472.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00191
epssPercentile: 0.08725
ingestedAt: '2026-10-15T03:30:12.788Z'
---

## Overview

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

iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index()

Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index()
where shifting the constant "1" (of type int) by bitmap->mapped.pgshift
(an unsigned long value) could result in undefined behavior.

The constant "1" defaults to a 32-bit "int", and when "pgshift" exceeds
31 (e.g., pgshift = 63) the shift operation overflows, as the result
cannot be represented in a 32-bit type.

To resolve this, the constant is updated to "1UL", promoting it to an
unsigned long type to match the operand's type.

## Affected

- `linux_kernel >= 6.1, < 6.1.129`
- `linux_kernel >= 6.2, < 6.6.76`
- `linux_kernel >= 6.7, < 6.12.13`
- `linux_kernel >= 6.13, < 6.13.2`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.13.2`