---
id: CVE-2024-26786
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  iommufd: Fix iopt_access_list_id overwrite bug

  Syzkaller reported the following WARN_ON:
    WARNING: CPU: 1 PID: 4738 at drivers/iommu/iommufd/io_pagetable.c:1360

    Ca…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  iommufd: Fix iopt_access_list_id overwrite bug

  Syzkaller reported the following WARN_ON:
    WARNING: CPU: 1 PID: 4738 at drivers/iommu/iommufd/io_pagetable.c:1360

    Ca…
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-476
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 6.6, < 6.6.21'
  - 'linux_kernel >= 6.7, < 6.7.9'
  - linux_kernel = 6.8
patched:
  - linux_kernel 6.7.9
published: '2024-04-04'
updated: '2026-08-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-26786'
references:
  - url: 'https://git.kernel.org/stable/c/9526a46cc0c378d381560279bea9aa34c84298a0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/aeb004c0cd6958e910123a1607634401009c9539'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f1fb745ee0a6fe43f1d84ec369c7e6af2310fda9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9526a46cc0c378d381560279bea9aa34c84298a0'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/aeb004c0cd6958e910123a1607634401009c9539'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/f1fb745ee0a6fe43f1d84ec369c7e6af2310fda9'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00231
epssPercentile: 0.12381
ingestedAt: '2026-08-05T10:46:48.941Z'
---

## Overview

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

iommufd: Fix iopt_access_list_id overwrite bug

Syzkaller reported the following WARN_ON:
  WARNING: CPU: 1 PID: 4738 at drivers/iommu/iommufd/io_pagetable.c:1360

  Call Trace:
   iommufd_access_change_ioas+0x2fe/0x4e0
   iommufd_access_destroy_object+0x50/0xb0
   iommufd_object_remove+0x2a3/0x490
   iommufd_object_destroy_user
   iommufd_access_destroy+0x71/0xb0
   iommufd_test_staccess_release+0x89/0xd0
   __fput+0x272/0xb50
   __fput_sync+0x4b/0x60
   __do_sys_close
   __se_sys_close
   __x64_sys_close+0x8b/0x110
   do_syscall_x64

The mismatch between the access pointer in the list and the passed-in
pointer is resulting from an overwrite of access->iopt_access_list_id, in
iopt_add_access(). Called from iommufd_access_change_ioas() when
xa_alloc() succeeds but iopt_calculate_iova_alignment() fails.

Add a new_id in iopt_add_access() and only update iopt_access_list_id when
returning successfully.

## Affected

- `linux_kernel >= 6.6, < 6.6.21`
- `linux_kernel >= 6.7, < 6.7.9`
- `linux_kernel = 6.8`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.7.9`