---
id: CVE-2026-74713
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  vhost_iotlb: bound map allocation in add_range

  vhost_iotlb_add_range_ctx() only retires an old entry when the table
  has a non-zero limit, has exactly reached that limi…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  vhost_iotlb: bound map allocation in add_range

  vhost_iotlb_add_range_ctx() only retires an old entry when the table
  has a non-zero limit, has exactly reached that limi…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'
published: '2026-08-22'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74713'
references:
  - url: 'https://git.kernel.org/stable/c/1ed35ac7f3fe2b4396bdd29ac3a7f0ebc0829e94'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ae128dd19040ee06a4f8143c7ced4d18080d7a9a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.0016
epssPercentile: 0.04728
ingestedAt: '2026-10-14T13:30:58.545Z'
---

## Overview

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

vhost_iotlb: bound map allocation in add_range

vhost_iotlb_add_range_ctx() only retires an old entry when the table
has a non-zero limit, has exactly reached that limit and has
VHOST_IOTLB_FLAG_RETIRE set. Non-retiring tables can keep allocating
entries after reaching their configured limit.

Existing vhost devices allocate their IOTLB with max_iotlb_entries from
vhost.c, which defaults to 2048 and is tunable by module parameter. Use
the caller-provided limit at the allocation point instead of adding a
separate default in the common IOTLB helper, and reject non-positive
values in vhost paths that can report an error.

Other vhost IOTLB users should not create zero-limit tables when entries
can be populated from userspace or guest-controlled requests. Add
caller-side max_iotlb_entries parameters for mlx5 vDPA, VDUSE and
vhost-vDPA. Reject non-positive VDUSE and vhost-vDPA values, and require
at least two entries for vdpa_sim and mlx5 vDPA paths that install
full-range mappings, since those mappings are split into two IOTLB
entries.

Handle full-range mappings in the common helper by checking that the
IOTLB can hold both split entries before inserting the first half. This
avoids returning an error after leaving a half mapping behind.

When the table is full, keep the existing retire behavior for retiring
tables and return -ENOSPC for non-retiring tables. Reuse the retired map
node instead of freeing it and allocating a replacement, so a stream of
IOTLB updates cannot keep forcing GFP_ATOMIC allocations after the table
has reached its limit. If a zero-limit IOTLB still reaches the common
helper, treat it as a configuration error and return -EINVAL.

I found this bug myself, though the patch was written with AI assistance.

## Remediation

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