---
id: CVE-2026-89509
title: 'RDMA/ionic: Embed counter driver data in rdma_counter allocation'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  RDMA/ionic: Embed counter driver data in rdma_counter allocation

  Commit 7e53b31acc7f ("RDMA/core: Create and destroy rdma_counter using
  rdma_zalloc_drv_obj()") require…
severity: medium
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-476
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 <
    c98197ee3cd28288da13dc9881bb9e74daa7cbbc
  - >-
    Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 <
    08b8630b557828aedb1d9ef0a6e2ec421f334ee2
  - >-
    Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 <
    cf3ebd89e754015625fee90aa938f6bc79a2c974
  - Linux 6.18
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:48:00.667Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89509'
references:
  - url: 'https://git.kernel.org/stable/c/c98197ee3cd28288da13dc9881bb9e74daa7cbbc'
  - url: 'https://git.kernel.org/stable/c/08b8630b557828aedb1d9ef0a6e2ec421f334ee2'
  - url: 'https://git.kernel.org/stable/c/cf3ebd89e754015625fee90aa938f6bc79a2c974'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89509.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89509'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532215'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89509'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89509'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89509.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00206
epssPercentile: 0.10622
ingestedAt: '2026-09-14T11:11:19.887Z'
---

## Overview

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

RDMA/ionic: Embed counter driver data in rdma_counter allocation

Commit 7e53b31acc7f ("RDMA/core: Create and destroy rdma_counter using
rdma_zalloc_drv_obj()") requires drivers implementing counter ops to
embed struct rdma_counter in a driver-specific struct, register its size
via INIT_RDMA_OBJ_SIZE, and provide a counter_init callback.

The ionic driver was merged without this adaptation, causing a NULL
pointer dereference in alloc_and_bind() since rdma_zalloc_drv_obj()
allocates zero bytes when size_rdma_counter is unset.

Consolidate struct ionic_counter into a new struct ionic_rdma_counter
that embeds struct rdma_counter, replace the xarray with a lightweight
ida for ID allocation, and add the required counter_init and
INIT_RDMA_OBJ_SIZE declarations.

## Affected

- `Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 < c98197ee3cd28288da13dc9881bb9e74daa7cbbc`
- `Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 < 08b8630b557828aedb1d9ef0a6e2ec421f334ee2`
- `Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 < cf3ebd89e754015625fee90aa938f6bc79a2c974`
- `Linux 6.18`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89509.json)