---
id: CVE-2026-89543
title: >-
  In the Linux kernel, the following vulnerability has been resolved:


  sunrpc: fix use-after-free in __rpc_clnt_handle_event and
  __rpc_clnt_remove_pipedir


  Normal client creation goes through rpc_setup_pipedir(), which records

  clnt->pipefs…
summary: >-
  In the Linux kernel, the following vulnerability has been resolved:


  sunrpc: fix use-after-free in __rpc_clnt_handle_event and
  __rpc_clnt_remove_pipedir


  Normal client creation goes through rpc_setup_pipedir(), which records

  clnt->pipefs…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-825
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= bfca5fb4e97c46503ddfc582335917b0cc228264 <
    59527bbfb1eabdb28e95e7c725886cc2c2899cb3
  - >-
    Linux >= bfca5fb4e97c46503ddfc582335917b0cc228264 <
    e769fcde3cc73e847b1eb3acd40c04a291cb0c0c
  - >-
    Linux >= bfca5fb4e97c46503ddfc582335917b0cc228264 <
    cdf7a233cb94774b0e7df42d9157077983f5022c
  - >-
    Linux >= bfca5fb4e97c46503ddfc582335917b0cc228264 <
    932a8cf6abb2b2f8677b79153a823108d8861fe2
  - Linux 17866066b8ac1cc38fb449670bc15dc9fee4b40a
  - Linux 7d61d1da2ed1f682c41cae0c8d4719cdaccee5c5
  - Linux dedf2a0eb9448ae73b270743e6ea9b108189df46
  - Linux 194454afa6aa9d6ed74f0c57127bc8beb27c20df
  - Linux 7749fd2dbef72a52b5c9ffdbf877691950ed4680
  - Linux 1cdb52ffd6600a37bd355d8dce58ecd03e55e618
  - Linux cc2e7ebbeb1d0601f7f3c8d93b78fcc03a95e44a
  - Linux >= 4.19.318 < 4.20
  - Linux >= 5.4.280 < 5.5
  - Linux >= 5.10.202 < 5.11
  - Linux >= 5.15.140 < 5.16
  - Linux >= 6.1.64 < 6.2
  - Linux >= 6.5.13 < 6.6
  - Linux >= 6.6.3 < 6.7
  - Linux 6.7
published: '2026-09-11'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T14:17:22.840'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89543'
references:
  - url: 'https://git.kernel.org/stable/c/59527bbfb1eabdb28e95e7c725886cc2c2899cb3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/932a8cf6abb2b2f8677b79153a823108d8861fe2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cdf7a233cb94774b0e7df42d9157077983f5022c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e769fcde3cc73e847b1eb3acd40c04a291cb0c0c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89543.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89543'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532038'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89543'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89543'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89543.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00209
epssPercentile: 0.0974
cvssSource: vendor
ingestedAt: '2026-09-14T11:11:19.886Z'
---

## Overview

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

sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir

Normal client creation goes through rpc_setup_pipedir(), which records
clnt->pipefs_sb, but the mount-event path in __rpc_clnt_handle_event()
calls rpc_setup_pipedir_sb() directly and never refreshes that field.
The umount path also removes the directory without clearing
clnt->pipefs_sb.

After a late pipefs mount or any remount, rpc_clnt_remove_pipedir()
compares the current superblock against a stale pipefs_sb pointer and
skips cleanup, leaving pipefs dentries whose inode private data still
points at a freed rpc_clnt, leading to a potential use-after-free during
subsequent rpc_info_open() or rpc_show_info() calls.

Fix this by properly updating clnt->pipefs_sb upon mount events and
clearing it during unmount or failure paths.

## 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 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 8, Red Hat Enterprise Linux 9, … · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89543.json)