---
id: CVE-2026-90244
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  iommu/dma: Restore locking around msi_page_list

  Unlike a group's default domain, which is always freshly allocated
  and privately owned (iommu_group_alloc_default_domai…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  iommu/dma: Restore locking around msi_page_list

  Unlike a group's default domain, which is always freshly allocated
  and privately owned (iommu_group_alloc_default_domai…
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'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 288683c92b1abc32277c83819bea287af614d239 <
    e3c53e9173a47d5ce1fae020f2c6b1fb3c1123c2
  - >-
    Linux >= 288683c92b1abc32277c83819bea287af614d239 <
    2af1e99ec14d226d66ceb9f16c663ee2568e6676
  - >-
    Linux >= 288683c92b1abc32277c83819bea287af614d239 <
    5a9e89ea34e0e34ac5d7e949042d665533549e40
  - Linux 6.15
published: '2026-09-17'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:17:50.720'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90244'
references:
  - url: 'https://git.kernel.org/stable/c/2af1e99ec14d226d66ceb9f16c663ee2568e6676'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5a9e89ea34e0e34ac5d7e949042d665533549e40'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e3c53e9173a47d5ce1fae020f2c6b1fb3c1123c2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00173
epssPercentile: 0.05937
ingestedAt: '2026-09-17T16:21:47.846Z'
---

## Overview

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

iommu/dma: Restore locking around msi_page_list

Unlike a group's default domain, which is always freshly allocated
and privately owned (iommu_group_alloc_default_domain()), VFIO type1's
legacy container merges any newly attached group into an existing
domain whenever their iommu_ops and cache-coherency enforcement match.

iommu_dma_get_msi_page() only asserts the caller's own group mutex is
held (iommu_group_mutex_assert()). On an IOMMU that publishes
IOMMU_RESV_SW_MSI, e.g. ARM SMMU, a VM with two such devices assigned
through the legacy container can have their guest drivers probe and
allocate MSIs in parallel; each host-side VFIO_DEVICE_SET_IRQS lands
on a different device fd and group mutex, but both devices' domains
are the same merged domain, so both can enter
iommu_dma_get_msi_page() concurrently and corrupt msi_page_list.

commit 288683c92b1a ("iommu: Make iommu_dma_prepare_msi() into a
generic operation") dropped the prior msi_prepare_lock on the
reasoning that "each iommu_domain is unique to a group," which holds
for default domains but not this VFIO type1 case. Restore the static
lock, since it's only guarding a corner case and will likely never
be contended.

iommufd avoids the equivalent problem by having its own callers
(iommufd_sw_map_msi()) take a ctx-wide sw_msi_lock before ever
reaching the shared list. VFIO type1 can't mirror that since it
dispatches to iommu_dma_sw_msi() which is outside VFIO's jurisdiction.

## Remediation

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