---
id: CVE-2026-80980
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/smc: stop killed, freed and out_of_sync sharing a byte

  The three connection state flags are single-bit bitfields, so they occupy
  one byte of struct smc_connection …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/smc: stop killed, freed and out_of_sync sharing a byte

  The three connection state flags are single-bit bitfields, so they occupy
  one byte of struct smc_connection …
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-366
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= b286a0651e4404ab96cdfdcdad8a839a26b3751e <
    09a9cbadc05f452405de31012bd2c428b601291a
  - >-
    Linux >= b286a0651e4404ab96cdfdcdad8a839a26b3751e <
    313f79149eb337411c64e2c247234b62ef9a3cb9
  - >-
    Linux >= b286a0651e4404ab96cdfdcdad8a839a26b3751e <
    2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec
  - >-
    Linux >= b286a0651e4404ab96cdfdcdad8a839a26b3751e <
    db51a8658c11a82432b64999519a269c3aabb447
  - Linux 5.8
published: '2026-09-11'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:17:41.440'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80980'
references:
  - url: 'https://git.kernel.org/stable/c/09a9cbadc05f452405de31012bd2c428b601291a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/313f79149eb337411c64e2c247234b62ef9a3cb9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/db51a8658c11a82432b64999519a269c3aabb447'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80980.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-80980'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532124'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-80980'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80980'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80980.mbox
  - url: 'https://git.kernel.org/stable/c/297e96f38d3e4f1a3b84068950dd5c7a55bbdc7b'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00635
epssPercentile: 0.50213
scores:
  nvd: 9.8
  vendor: 5.5
  cna: 9.8
ingestedAt: '2026-09-14T15:23:07.476Z'
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-16T19:21:47.866329Z'
---

## Overview

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

net/smc: stop killed, freed and out_of_sync sharing a byte

The three connection state flags are single-bit bitfields, so they occupy
one byte of struct smc_connection and every store to one is a
read-modify-write of the other two:

    u8  killed : 1;
    u8  freed : 1;
    u8  out_of_sync : 1;

They are not written under a common lock. smc_cdc_msg_validate() sets
out_of_sync from the receive tasklet, while smc_conn_kill() sets killed
from process context under lock_sock(), and the receive path does not defer
to the backlog when the socket is owned -- smc_cdc_msg_recv() takes only
bh_lock_sock().

Give each flag its own byte so a store no longer touches its neighbours.
All readers test them as booleans and are unchanged. struct smc_connection
grows by two bytes.

## Remediation

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

## 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 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80980.json)