---
id: CVE-2026-80733
title: 'net: remove WARN_ON_ONCE() from sk_mc_loop()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: remove WARN_ON_ONCE() from sk_mc_loop()

  sk_mc_loop() can be called for sockets that are neither AF_INET
  nor AF_INET6 (e.g. AF_PACKET sockets when sending packets …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 <
    97133c4d42654578fab95abe47359ebe784dde18
  - >-
    Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 <
    f625c742b33dc137c209dd13d1c5f12b1c18d71c
  - >-
    Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 <
    ad7fa2f411cb30f63d6725f111be134064cdb718
  - >-
    Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 <
    d2adc4e80b29e58b5162ae09f0f657a215806c8c
  - >-
    Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 <
    ad7dbb1d14b1b4406eca8ef9478e8de312ba0cfe
  - >-
    Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 <
    c8f256dc849205ccb2bd78bd99a3497b972b44e0
  - >-
    Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 <
    0d75f2c1d0764efa756ad9c1e078d8c09ea8fc1f
  - >-
    Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 <
    b8a39a09ae4eaae04309e1e38ed6a1101d967496
  - Linux c91f81773cd4bbebfe744e9ab30a7ce093f9b930
  - Linux c8c30b2b17f2133e953850c547e3902c3a3d80e2
  - Linux 3fe207e4637a2e792c46a08666aa722f77d7f8f7
  - Linux >= 3.14.40 < 3.15
  - Linux >= 3.18.13 < 3.19
  - Linux >= 3.19.6 < 3.20
  - Linux 4.0
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T17:02:55.348385Z'
published: '2026-09-03'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T17:05:53.381Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-80733'
references:
  - url: 'https://git.kernel.org/stable/c/97133c4d42654578fab95abe47359ebe784dde18'
  - url: 'https://git.kernel.org/stable/c/f625c742b33dc137c209dd13d1c5f12b1c18d71c'
  - url: 'https://git.kernel.org/stable/c/ad7fa2f411cb30f63d6725f111be134064cdb718'
  - url: 'https://git.kernel.org/stable/c/d2adc4e80b29e58b5162ae09f0f657a215806c8c'
  - url: 'https://git.kernel.org/stable/c/ad7dbb1d14b1b4406eca8ef9478e8de312ba0cfe'
  - url: 'https://git.kernel.org/stable/c/c8f256dc849205ccb2bd78bd99a3497b972b44e0'
  - url: 'https://git.kernel.org/stable/c/0d75f2c1d0764efa756ad9c1e078d8c09ea8fc1f'
  - url: 'https://git.kernel.org/stable/c/b8a39a09ae4eaae04309e1e38ed6a1101d967496'
tags:
  - cve.org
epss: 0.00177
epssPercentile: 0.07259
ingestedAt: '2026-11-06T18:00:12.534Z'
---

## Overview

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

net: remove WARN_ON_ONCE() from sk_mc_loop()

sk_mc_loop() can be called for sockets that are neither AF_INET
nor AF_INET6 (e.g. AF_PACKET sockets when sending packets via raw/packet
socket over virtual devices such as VRF or ipvlan).

In such cases, sk_family is not AF_INET/AF_INET6 and sk_mc_loop() falls
through the switch statement and triggers WARN_ON_ONCE(1).

Non-INET sockets do not support IP_MULTICAST_LOOP or IPV6_MULTICAST_LOOP
options, so loopback should default to true without generating a warning.

## Affected

- `Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 < 97133c4d42654578fab95abe47359ebe784dde18`
- `Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 < f625c742b33dc137c209dd13d1c5f12b1c18d71c`
- `Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 < ad7fa2f411cb30f63d6725f111be134064cdb718`
- `Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 < d2adc4e80b29e58b5162ae09f0f657a215806c8c`
- `Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 < ad7dbb1d14b1b4406eca8ef9478e8de312ba0cfe`
- `Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 < c8f256dc849205ccb2bd78bd99a3497b972b44e0`
- `Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 < 0d75f2c1d0764efa756ad9c1e078d8c09ea8fc1f`
- `Linux >= f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 < b8a39a09ae4eaae04309e1e38ed6a1101d967496`
- `Linux c91f81773cd4bbebfe744e9ab30a7ce093f9b930`
- `Linux c8c30b2b17f2133e953850c547e3902c3a3d80e2`
- `Linux 3fe207e4637a2e792c46a08666aa722f77d7f8f7`
- `Linux >= 3.14.40 < 3.15`
- `Linux >= 3.18.13 < 3.19`
- `Linux >= 3.19.6 < 3.20`
- `Linux 4.0`

## Remediation

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