---
id: CVE-2026-97421
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/umem: Be careful about boundary conditions in ib_umem_find_best_pgsz()

  Several corner cases, especially important on 32 bits:

  - umem->iova is u64, the function a…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/umem: Be careful about boundary conditions in ib_umem_find_best_pgsz()

  Several corner cases, especially important on 32 bits:

  - umem->iova is u64, the function a…
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 >= a40c20dabdf9045270767c75918feb67f0727c89 <
    3014da7587ce006cd08004fd6b257626b314e0a3
  - >-
    Linux >= a40c20dabdf9045270767c75918feb67f0727c89 <
    ddccf6cc3861de2fe60986933bead79220e0d797
  - >-
    Linux >= a40c20dabdf9045270767c75918feb67f0727c89 <
    e9bbb5f5349ef560ff6f0395564f04c3aa664559
  - >-
    Linux >= a40c20dabdf9045270767c75918feb67f0727c89 <
    ae3cf7d2c4d506c5c91746321644e1a08d989e2a
  - >-
    Linux >= a40c20dabdf9045270767c75918feb67f0727c89 <
    5fc5b73109540809b094710fac44da81dd8a3ff8
  - >-
    Linux >= a40c20dabdf9045270767c75918feb67f0727c89 <
    09ea6837a0434fb4db99528a5055b6d822135dcf
  - Linux 85e40ba1c4a5246b35e91c2ed69d4680426904d7
  - Linux 59f07434b297e2268f5d5c567db5b09145245cf1
  - Linux 488229b7729d7becf4c39c5e74fb709fb35115c2
  - Linux >= 5.4.73 < 5.5
  - Linux >= 5.8.17 < 5.9
  - Linux >= 5.9.2 < 5.10
  - Linux 5.10
published: '2026-09-24'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:17:54.257'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97421'
references:
  - url: 'https://git.kernel.org/stable/c/09ea6837a0434fb4db99528a5055b6d822135dcf'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3014da7587ce006cd08004fd6b257626b314e0a3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5fc5b73109540809b094710fac44da81dd8a3ff8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ae3cf7d2c4d506c5c91746321644e1a08d989e2a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ddccf6cc3861de2fe60986933bead79220e0d797'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e9bbb5f5349ef560ff6f0395564f04c3aa664559'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97421.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-97421'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2540452'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-97421'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97421'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97421.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00129
epssPercentile: 0.02537
ingestedAt: '2026-09-24T16:47:15.884Z'
cwe:
  - CWE-681
scores:
  nvd: 7.8
  vendor: 5.5
---

## Overview

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

RDMA/umem: Be careful about boundary conditions in ib_umem_find_best_pgsz()

Several corner cases, especially important on 32 bits:

- umem->iova is u64, the function argument should pass in u64 or
  iova will be truncated
- Check that the length is not too large for the iova
- Check that lengths > 4G don't overflow the GENMASK

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97421.json)