---
id: CVE-2026-74297
title: 'RDMA/mlx5: Fix undefined shift of user RQ WQE size'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/mlx5: Fix undefined shift of user RQ WQE size

  set_rq_size() computes the RQ WQE size as "1 << rq_wqe_shift" based on
  the user-provided rq_wqe_shift, which is only…
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'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c <
    9fff54929cc00849d738faa99f06c32399aeb026
  - >-
    Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c <
    b746f949c2ac2b041102836095d6d4a2ef21fa75
  - >-
    Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c <
    c1dbf52d24a8cb1aa56780ba51b72e7d495f258c
  - >-
    Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c <
    6fc874fdfb366bfb11c62e6af9a831c8be59ddda
  - >-
    Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c <
    42f3d2c8c18b92ea33e506a38b64f1a8986c2823
  - >-
    Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c <
    4b87a2497276a72fd63028e7419abf0fb7ed837b
  - >-
    Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c <
    b732db02a2b04cde393638df19de6251ce62a74e
  - >-
    Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c <
    d881d60223aac8fdc12b227d89c76e131e92a9cd
  - Linux 3.11
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T18:52:40.390681Z'
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T18:55:31.425Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74297'
references:
  - url: 'https://git.kernel.org/stable/c/9fff54929cc00849d738faa99f06c32399aeb026'
  - url: 'https://git.kernel.org/stable/c/b746f949c2ac2b041102836095d6d4a2ef21fa75'
  - url: 'https://git.kernel.org/stable/c/c1dbf52d24a8cb1aa56780ba51b72e7d495f258c'
  - url: 'https://git.kernel.org/stable/c/6fc874fdfb366bfb11c62e6af9a831c8be59ddda'
  - url: 'https://git.kernel.org/stable/c/42f3d2c8c18b92ea33e506a38b64f1a8986c2823'
  - url: 'https://git.kernel.org/stable/c/4b87a2497276a72fd63028e7419abf0fb7ed837b'
  - url: 'https://git.kernel.org/stable/c/b732db02a2b04cde393638df19de6251ce62a74e'
  - url: 'https://git.kernel.org/stable/c/d881d60223aac8fdc12b227d89c76e131e92a9cd'
tags:
  - cve.org
epss: 0.00176
epssPercentile: 0.06634
ingestedAt: '2026-10-16T19:46:24.382Z'
---

## Overview

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

RDMA/mlx5: Fix undefined shift of user RQ WQE size

set_rq_size() computes the RQ WQE size as "1 << rq_wqe_shift" based on
the user-provided rq_wqe_shift, which is only checked to be greater than
32, so shifts of 32 are still accepted. A shift of 31 also overflows a
signed integer, leading to undefined behavior.

Use check_shl_overflow() to compute the RQ WQE size and reject any
invalid values.

## Affected

- `Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c < 9fff54929cc00849d738faa99f06c32399aeb026`
- `Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c < b746f949c2ac2b041102836095d6d4a2ef21fa75`
- `Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c < c1dbf52d24a8cb1aa56780ba51b72e7d495f258c`
- `Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c < 6fc874fdfb366bfb11c62e6af9a831c8be59ddda`
- `Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c < 42f3d2c8c18b92ea33e506a38b64f1a8986c2823`
- `Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c < 4b87a2497276a72fd63028e7419abf0fb7ed837b`
- `Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c < b732db02a2b04cde393638df19de6251ce62a74e`
- `Linux >= e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c < d881d60223aac8fdc12b227d89c76e131e92a9cd`
- `Linux 3.11`

## Remediation

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