---
id: CVE-2026-80977
title: 'net: skbuff: don''t touch shared zerocopy state in skb_tx_error()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: skbuff: don't touch shared zerocopy state in skb_tx_error()

  skb_tx_error() completes the zerocopy uarg and clears
  SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_mana…
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'
cvssSource: cna
cwe:
  - CWE-821
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba <
    6493165034bca14033bf49c9cec7b45e97a91497
  - >-
    Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba <
    b4452349dcf4d561e13be768d5d278de58248930
  - >-
    Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba <
    363c4252ffc473a0203e91b83ede5519dfb8bd07
  - >-
    Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba <
    6ec22afc82a3cae07ade0a6ec361ae2532128ff5
  - >-
    Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba <
    15aa81b390d401abf4b8211042470e9e92e3b7fb
  - >-
    Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba <
    288f9970670841044ab030104fa6b6ed159949d0
  - >-
    Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba <
    0370da114a9bc044e248b85c6809d1b5e0c1f7f9
  - >-
    Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba <
    f66bdb1cc0fcd227a062378f8be0b5873aa5600a
  - Linux 3.8
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T19:21:39.834701Z'
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:46:01.788Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-80977'
references:
  - url: 'https://git.kernel.org/stable/c/6493165034bca14033bf49c9cec7b45e97a91497'
  - url: 'https://git.kernel.org/stable/c/b4452349dcf4d561e13be768d5d278de58248930'
  - url: 'https://git.kernel.org/stable/c/363c4252ffc473a0203e91b83ede5519dfb8bd07'
  - url: 'https://git.kernel.org/stable/c/6ec22afc82a3cae07ade0a6ec361ae2532128ff5'
  - url: 'https://git.kernel.org/stable/c/15aa81b390d401abf4b8211042470e9e92e3b7fb'
  - url: 'https://git.kernel.org/stable/c/288f9970670841044ab030104fa6b6ed159949d0'
  - url: 'https://git.kernel.org/stable/c/0370da114a9bc044e248b85c6809d1b5e0c1f7f9'
  - url: 'https://git.kernel.org/stable/c/f66bdb1cc0fcd227a062378f8be0b5873aa5600a'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80977.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-80977'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532197'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-80977'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80977'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80977.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00129
epssPercentile: 0.02536
scores:
  cna: 7.8
  vendor: 7
ingestedAt: '2026-09-14T15:23:07.455Z'
---

## Overview

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

net: skbuff: don't touch shared zerocopy state in skb_tx_error()

skb_tx_error() completes the zerocopy uarg and clears
SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_managed() clears
SKBFL_MANAGED_FRAG_REFS. Both live in skb_shinfo(), which every clone
shares, while the caller only owns the reference it is about to drop.
Through a clone it tells the producer its pages are free and drops
SKBFL_SHARED_FRAG for an skb that is still in flight.

Open vSwitch reaches this with a non-last OVS_ACTION_ATTR_RECIRC:
clone_execute() sends a skb_clone() into ovs_dp_process_packet() while
do_execute_actions() keeps forwarding the original, and skb_clone()
does not privatise the frags here -- skb_orphan_frags() returns early
on SKBFL_DONT_ORPHAN. A flow miss on the clone then strips the marker
from the packet still being forwarded, and a later local ESP delivery
decrypts in place over frags it does not own privately.

Skip it for a cloned skb. Nothing is lost: skb_release_data() clears
the zerocopy state once the last reference to the shared data goes.

## Affected

- `Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba < 6493165034bca14033bf49c9cec7b45e97a91497`
- `Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba < b4452349dcf4d561e13be768d5d278de58248930`
- `Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba < 363c4252ffc473a0203e91b83ede5519dfb8bd07`
- `Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba < 6ec22afc82a3cae07ade0a6ec361ae2532128ff5`
- `Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba < 15aa81b390d401abf4b8211042470e9e92e3b7fb`
- `Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba < 288f9970670841044ab030104fa6b6ed159949d0`
- `Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba < 0370da114a9bc044e248b85c6809d1b5e0c1f7f9`
- `Linux >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba < f66bdb1cc0fcd227a062378f8be0b5873aa5600a`
- `Linux 3.8`

## 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 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80977.json)