---
id: CVE-2026-93264
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/efa: Fix PBL chunk length computation

  On register MR, when creating the PBL, if it's an indirect PBL we create
  a chunk list to hold the PBL pages pointers
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/efa: Fix PBL chunk length computation

  On register MR, when creating the PBL, if it's an indirect PBL we create
  a chunk list to hold the PBL pages pointers. Each c…
severity: medium
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 40909f664d279765af430acc5db348a0b71c9b0a <
    665cd418b8561a099c3854443f8ad8ae751b72a0
  - >-
    Linux >= 40909f664d279765af430acc5db348a0b71c9b0a <
    932e5684906a090644a9061fae2d254041c3b8f2
  - >-
    Linux >= 40909f664d279765af430acc5db348a0b71c9b0a <
    489b28f2377afa70c18c45b06a6387f3d39bb123
  - >-
    Linux >= 40909f664d279765af430acc5db348a0b71c9b0a <
    aadf3f9b5edb7f0a77e9172b237d2e07c754829c
  - >-
    Linux >= 40909f664d279765af430acc5db348a0b71c9b0a <
    3982714e15512b83115897806dacc94899683420
  - >-
    Linux >= 40909f664d279765af430acc5db348a0b71c9b0a <
    da7805f0211af19968584e621074f253ac07dba7
  - >-
    Linux >= 40909f664d279765af430acc5db348a0b71c9b0a <
    1d4b5902773475fc97151379b7e5f09cad0fa57b
  - >-
    Linux >= 40909f664d279765af430acc5db348a0b71c9b0a <
    229b42d7450c1cf96f45ec39ebb69211b06bc036
  - Linux 5.2
published: '2026-09-24'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T16:17:23.193'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93264'
references:
  - url: 'https://git.kernel.org/stable/c/1d4b5902773475fc97151379b7e5f09cad0fa57b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/229b42d7450c1cf96f45ec39ebb69211b06bc036'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3982714e15512b83115897806dacc94899683420'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/489b28f2377afa70c18c45b06a6387f3d39bb123'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/665cd418b8561a099c3854443f8ad8ae751b72a0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/932e5684906a090644a9061fae2d254041c3b8f2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/aadf3f9b5edb7f0a77e9172b237d2e07c754829c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/da7805f0211af19968584e621074f253ac07dba7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93264.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-93264'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2540367'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-93264'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93264'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93264.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-09-24T16:47:15.836Z'
epss: 0.00201
epssPercentile: 0.0997
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-787
---

## Overview

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

RDMA/efa: Fix PBL chunk length computation

On register MR, when creating the PBL, if it's an indirect PBL we create
a chunk list to hold the PBL pages pointers. Each chunk is 4KB in size
and can hold 510 addresses (EFA_PTRS_PER_CHUNK) and has a 12-byte
control buffer at the end of it holding the next chunk's pointer and its
length.

If the PBL number of pages is a multiple of EFA_PTRS_PER_CHUNK, the
calculated last chunk length is wrongly computed as 0, even though that
chunk is fully populated with 510 real page pointers. This wrong length
is used both to DMA map the chunk and is propagated to the device,
causing the device to see the chunk as empty and reject the memory
registration.

Fix the calculation so it will be performed only if the number of pages
isn't a multiple of EFA_PTRS_PER_CHUNK, if it is, its already handled in
the above loop correctly.
Also prevent out-of-bounds reach in the chunks array in such scenario.

## 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-2026-93264.json)