---
id: CVE-2026-74378
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe

  get_srq_wqe() reads wqe->dma.num_sge from the shared receive queue
  buffer, which is mapped into userspace
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe

  get_srq_wqe() reads wqe->dma.num_sge from the shared receive queue
  buffer, which is mapped into userspace. It validat…
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 >= 8700e3e7c4857d28ebaa824509934556da0b3e76 <
    c8db0e5ab0b6c540214c46c56aaac7cbcb0967fe
  - >-
    Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 <
    e48daa94ad2d406225b73491fc935064716f0ec7
  - >-
    Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 <
    3cfa2a3adc51b7c57729961a03446962ff10e3d2
  - >-
    Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 <
    cd19a6345e3727adafafa5954b58b13c92e13b80
  - >-
    Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 <
    3e07ea9579dc9553d2285c26c2823931358aa3b8
  - >-
    Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 <
    02558c86b6b761063e9399e6b939984500327ef1
  - >-
    Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 <
    b9800d7953d119bcc068c74587d48e4ba0313629
  - >-
    Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 <
    22b8fbded65b8c441b634a185f8da67657df6c50
  - Linux 4.8
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T19:17:42.837'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74378'
references:
  - url: 'https://git.kernel.org/stable/c/02558c86b6b761063e9399e6b939984500327ef1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/22b8fbded65b8c441b634a185f8da67657df6c50'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3cfa2a3adc51b7c57729961a03446962ff10e3d2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3e07ea9579dc9553d2285c26c2823931358aa3b8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b9800d7953d119bcc068c74587d48e4ba0313629'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c8db0e5ab0b6c540214c46c56aaac7cbcb0967fe'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cd19a6345e3727adafafa5954b58b13c92e13b80'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e48daa94ad2d406225b73491fc935064716f0ec7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00143
epssPercentile: 0.03549
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T18:54:53.282881Z'
ingestedAt: '2026-09-14T15:23:07.456Z'
---

## Overview

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

RDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe

get_srq_wqe() reads wqe->dma.num_sge from the shared receive queue
buffer, which is mapped into userspace. It validates num_sge against
max_sge, but then re-reads the same field to calculate the memcpy
size. A concurrent userspace thread can modify num_sge between
validation and use, causing a heap buffer overflow when copying the
WQE into qp->resp.srq_wqe.

Read num_sge into a local variable and use it for both the bounds
check and the size calculation.

## Remediation

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