---
id: CVE-2026-90309
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/erdma: Hold CQ references when processing EQ events

  EQ handlers look up CQs from dev->cq_xa and invoke CQ completion or
  error callbacks outside the xarray lock
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/erdma: Hold CQ references when processing EQ events

  EQ handlers look up CQs from dev->cq_xa and invoke CQ completion or
  error callbacks outside the xarray lock. e…
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 >= 155055771704f8cbb5c176a4309b7dc30a50450c <
    610ef81797bb4f709e8675c1d8d093bb9ccdcbd8
  - >-
    Linux >= 155055771704f8cbb5c176a4309b7dc30a50450c <
    c0a83f29a24c7e7f8516630848ef6db4c174deed
  - >-
    Linux >= 155055771704f8cbb5c176a4309b7dc30a50450c <
    05b8ca493dd02319bca93c640b259c2ba51ef321
  - >-
    Linux >= 155055771704f8cbb5c176a4309b7dc30a50450c <
    1fc9c1933959d2776a1ce7bf424251b8b5b586cd
  - >-
    Linux >= 155055771704f8cbb5c176a4309b7dc30a50450c <
    4545f355654d044d35a31cd01cc46f491a8a7c36
  - >-
    Linux >= 155055771704f8cbb5c176a4309b7dc30a50450c <
    98df2aee1459ee1c62c70cbe9b370d2a532aea36
  - Linux 6.0
published: '2026-09-17'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:17:52.977'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90309'
references:
  - url: 'https://git.kernel.org/stable/c/05b8ca493dd02319bca93c640b259c2ba51ef321'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1fc9c1933959d2776a1ce7bf424251b8b5b586cd'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4545f355654d044d35a31cd01cc46f491a8a7c36'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/610ef81797bb4f709e8675c1d8d093bb9ccdcbd8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/98df2aee1459ee1c62c70cbe9b370d2a532aea36'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c0a83f29a24c7e7f8516630848ef6db4c174deed'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00176
epssPercentile: 0.06301
ingestedAt: '2026-09-17T16:21:47.827Z'
---

## Overview

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

RDMA/erdma: Hold CQ references when processing EQ events

EQ handlers look up CQs from dev->cq_xa and invoke CQ completion or
error callbacks outside the xarray lock. erdma_destroy_cq() can erase the
CQ from the xarray and free its queue buffer and doorbell record while a
previously scheduled EQ handler is still using the CQ.

Add a CQ refcount and take a reference under the xarray lock with
refcount_inc_not_zero(). Remove the CQ from the xarray before dropping
the destroy-path reference, then wait for in-flight EQ users before
releasing CQ resources.

## Remediation

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