---
id: CVE-2026-80988
title: 'NTB: ntb_transport: Fail TX enqueue when the QP link is down'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  NTB: ntb_transport: Fail TX enqueue when the QP link is down

  Commit f195a1a6fe41 ("ntb: Drop packets when qp link is down") meant to
  make ntb_transport_tx_enqueue() dr…
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-772
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 3cfdc448e8bfa8a7eaa5af87f357330566124b78 <
    76c9ccc0c6bebfc74c0e727eda67687f5103ab06
  - >-
    Linux >= bfa051f650a7708183bd86901ca4645dcf88c486 <
    96d792c65b9d5f7f9dd86a1004315db59e450c07
  - >-
    Linux >= 4f4af6b8b7a23fa37decaf43b55403e6bfd8e219 <
    45cc11035165918dd1f81796ea98f81ece20d361
  - >-
    Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 <
    e6cc541fab01099fd8efadfa4f13afdf118bf536
  - >-
    Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 <
    5eca0d899a3be661a7e2caaaa7467a6fa15d756c
  - >-
    Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 <
    894e136b432da75c0352c80299807a5c4b04f167
  - >-
    Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 <
    89177732fe1653bbfef10cf5d99bf20cf57762c2
  - >-
    Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 <
    873ce713fef5dde0939220f04f3484ec86a16fba
  - Linux aa6d6ed213b62cbdb09ea32abbfa085dd987a0c9
  - Linux a8986a61ebee0b54c5d648444fbae09bd1c6dcd2
  - Linux 94491412a2afc8a5aea4c5b455aed86d3486f0b1
  - Linux c2cd5d993f57f819d46fe62387d3cc34d8468e60
  - Linux 449b1978d4e50b14b2a4de3a26d0b074593926a3
  - Linux >= 5.10.195 < 5.10.270
  - Linux >= 5.15.132 < 5.15.221
  - Linux >= 6.1.53 < 6.1.188
  - Linux >= 4.14.326 < 4.15
  - Linux >= 4.19.295 < 4.20
  - Linux >= 5.4.257 < 5.5
  - Linux >= 6.4.16 < 6.5
  - Linux >= 6.5.3 < 6.6
  - Linux 6.6
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:46:12.548Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-80988'
references:
  - url: 'https://git.kernel.org/stable/c/76c9ccc0c6bebfc74c0e727eda67687f5103ab06'
  - url: 'https://git.kernel.org/stable/c/96d792c65b9d5f7f9dd86a1004315db59e450c07'
  - url: 'https://git.kernel.org/stable/c/45cc11035165918dd1f81796ea98f81ece20d361'
  - url: 'https://git.kernel.org/stable/c/e6cc541fab01099fd8efadfa4f13afdf118bf536'
  - url: 'https://git.kernel.org/stable/c/5eca0d899a3be661a7e2caaaa7467a6fa15d756c'
  - url: 'https://git.kernel.org/stable/c/894e136b432da75c0352c80299807a5c4b04f167'
  - url: 'https://git.kernel.org/stable/c/89177732fe1653bbfef10cf5d99bf20cf57762c2'
  - url: 'https://git.kernel.org/stable/c/873ce713fef5dde0939220f04f3484ec86a16fba'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80988.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-80988'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532251'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-80988'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80988'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80988.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00177
epssPercentile: 0.07153
ingestedAt: '2026-09-14T15:23:07.454Z'
---

## Overview

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

NTB: ntb_transport: Fail TX enqueue when the QP link is down

Commit f195a1a6fe41 ("ntb: Drop packets when qp link is down") meant to
make ntb_transport_tx_enqueue() drop packets submitted while the QP link
is down, but it only returns 0 without consuming the packet. Zero means
success by this function's contract, so ntb_netdev reports NETDEV_TX_OK
and forgets the skb: nothing queued it, nothing frees it, and it leaks,
one skb for every transmit racing a link-down.

Return -ENOLINK instead, restoring the contract that a non-zero return
leaves the buffer owned by the caller. With the preceding patch,
ntb_netdev frees the skb on non-retryable enqueue failures and returns
NETDEV_TX_OK, so a packet racing with link-down is dropped without leaking
or entering a busy retry loop.

## Affected

- `Linux >= 3cfdc448e8bfa8a7eaa5af87f357330566124b78 < 76c9ccc0c6bebfc74c0e727eda67687f5103ab06`
- `Linux >= bfa051f650a7708183bd86901ca4645dcf88c486 < 96d792c65b9d5f7f9dd86a1004315db59e450c07`
- `Linux >= 4f4af6b8b7a23fa37decaf43b55403e6bfd8e219 < 45cc11035165918dd1f81796ea98f81ece20d361`
- `Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 < e6cc541fab01099fd8efadfa4f13afdf118bf536`
- `Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 < 5eca0d899a3be661a7e2caaaa7467a6fa15d756c`
- `Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 < 894e136b432da75c0352c80299807a5c4b04f167`
- `Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 < 89177732fe1653bbfef10cf5d99bf20cf57762c2`
- `Linux >= f195a1a6fe416882984f8bd6c61afc1383171860 < 873ce713fef5dde0939220f04f3484ec86a16fba`
- `Linux aa6d6ed213b62cbdb09ea32abbfa085dd987a0c9`
- `Linux a8986a61ebee0b54c5d648444fbae09bd1c6dcd2`
- `Linux 94491412a2afc8a5aea4c5b455aed86d3486f0b1`
- `Linux c2cd5d993f57f819d46fe62387d3cc34d8468e60`
- `Linux 449b1978d4e50b14b2a4de3a26d0b074593926a3`
- `Linux >= 5.10.195 < 5.10.270`
- `Linux >= 5.15.132 < 5.15.221`
- `Linux >= 6.1.53 < 6.1.188`
- `Linux >= 4.14.326 < 4.15`
- `Linux >= 4.19.295 < 4.20`
- `Linux >= 5.4.257 < 5.5`
- `Linux >= 6.4.16 < 6.5`
- `Linux >= 6.5.3 < 6.6`
- `Linux 6.6`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80988.json)