---
id: CVE-2026-98559
title: >-
  kernel: net/smc: fix UAF on lgr list traversal in smcr_port_err()
  (CVE-2026-98559)
summary: >-
  A flaw was found in the Linux kernel's Shared Memory Communications (SMC)
  subsystem. When processing port errors, the kernel traverses active link
  groups without holding the appropriate lock, allowing a concurrent termination
  event to free…
severity: medium
cvss: 4.7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-825
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 8
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-10-18'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T02:22:04+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98559.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98559.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98559'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2555033'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98559'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98559'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98559.mbox
  - url: 'https://git.kernel.org/stable/c/34bcf11cd2528ae00bb6d764d808083c66824277'
  - url: 'https://git.kernel.org/stable/c/0edcc4284392b28826b5d37532b366b291e6e0fa'
  - url: 'https://git.kernel.org/stable/c/00a59600ae72d24859d0ad1783a78bc921bc2599'
  - url: 'https://git.kernel.org/stable/c/3d35f069e1c119992000d51236dbe54da2d4e61e'
  - url: 'https://git.kernel.org/stable/c/3d65a2eb4449fc9658fb860dea893025d028d90e'
  - url: 'https://git.kernel.org/stable/c/a9b968e42690d784c241a0761c10253271f7df5d'
  - url: 'https://git.kernel.org/stable/c/61cb282fe97b3b0ba32ca09417a693162bf4ae3f'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00211
epssPercentile: 0.11314
ingestedAt: '2026-10-18T15:45:12.262Z'
---

## Overview

A flaw was found in the Linux kernel's Shared Memory Communications (SMC) subsystem. When processing port errors, the kernel traverses active link groups without holding the appropriate lock, allowing a concurrent termination event to free memory while it is still in use. An attacker capable of inducing these concurrent network events could exploit this race condition to trigger a use-after-free flaw, leading to a Denial of Service (DoS) via a system crash.

## 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 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98559.json)

**kernel: net/smc: fix UAF on lgr list traversal in smcr_port_err()** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-20.

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

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7

## Remediation

Fix deferred