---
id: CVE-2026-89450
title: 'iommu/tegra241-cmdqv: Reject a vSID wider than the SID_MATCH field'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  iommu/tegra241-cmdqv: Reject a vSID wider than the SID_MATCH field

  tegra241_vintf_init_vsid() programs the guest-provided vSID into SID_MATCH,
  whose VIRT_SID field spa…
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'
cvssSource: cna
cwe:
  - CWE-681
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 <
    d903d99ffd22b0180bd745a43f221c21bcdd8d7c
  - >-
    Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 <
    445204550f894ca325ac80a21e3df177ad073798
  - >-
    Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 <
    4379610c79bd88ddbea10e7f6c21e16d4b338c6b
  - Linux 6.17
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:46:59.901Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89450'
references:
  - url: 'https://git.kernel.org/stable/c/d903d99ffd22b0180bd745a43f221c21bcdd8d7c'
  - url: 'https://git.kernel.org/stable/c/445204550f894ca325ac80a21e3df177ad073798'
  - url: 'https://git.kernel.org/stable/c/4379610c79bd88ddbea10e7f6c21e16d4b338c6b'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89450.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89450'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532062'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89450'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89450'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89450.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00127
epssPercentile: 0.02377
scores:
  cna: 8.8
  vendor: 7.8
ingestedAt: '2026-09-14T15:23:07.475Z'
---

## Overview

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

iommu/tegra241-cmdqv: Reject a vSID wider than the SID_MATCH field

tegra241_vintf_init_vsid() programs the guest-provided vSID into SID_MATCH,
whose VIRT_SID field spans bits [20:1] with bit 0 as the match-enable flag.
The HW therefore matches only a 20-bit Stream ID.

The bound check rejects only virt_sid > UINT_MAX, which admits a value far
wider than the field. The write "virt_sid << 1 | 0x1" then drops every bit
above 20: a virt_sid of 0x80000000 lands as SID_MATCH = 0x1, a valid match
on vSID 0, so the entry aliases the wrong Stream ID. Because vdev->virt_id
is guest-controlled, a VMM can trigger it.

Validate virt_sid against the field width with FIELD_MAX(), and program the
register with FIELD_PREP() so the value and the field stay consistent.

## Affected

- `Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < d903d99ffd22b0180bd745a43f221c21bcdd8d7c`
- `Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < 445204550f894ca325ac80a21e3df177ad073798`
- `Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < 4379610c79bd88ddbea10e7f6c21e16d4b338c6b`
- `Linux 6.17`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-09-27 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89450.json)