---
id: CVE-2026-93212
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: guard nfsd_serv deref in nfsd_file_net_dispose

  nfsd_file_net_dispose() is the consumer side of l->freeme: the nfsd
  service thread loop calls it to drain entries …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: guard nfsd_serv deref in nfsd_file_net_dispose

  nfsd_file_net_dispose() is the consumer side of l->freeme: the nfsd
  service thread loop calls it to drain entries …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ffb402596147ac583f3464ff5c48feb9423e3838 <
    f4776c1c4b38fbc459420321c8ece87d0f7f95fb
  - >-
    Linux >= ffb402596147ac583f3464ff5c48feb9423e3838 <
    59baf45a06435194005fc5fa9a42d89f77a30432
  - >-
    Linux >= ffb402596147ac583f3464ff5c48feb9423e3838 <
    766170b4fd2daaf5c4d6735560101474e18edab6
  - >-
    Linux >= ffb402596147ac583f3464ff5c48feb9423e3838 <
    9f1ddfc8cb9076592401a611eb3a44d36186d014
  - Linux 6.9
published: '2026-09-24'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T16:17:16.133'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93212'
references:
  - url: 'https://git.kernel.org/stable/c/59baf45a06435194005fc5fa9a42d89f77a30432'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/766170b4fd2daaf5c4d6735560101474e18edab6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9f1ddfc8cb9076592401a611eb3a44d36186d014'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f4776c1c4b38fbc459420321c8ece87d0f7f95fb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-24T15:45:56.671Z'
epss: 0.00168
epssPercentile: 0.05399
---

## Overview

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

nfsd: guard nfsd_serv deref in nfsd_file_net_dispose

nfsd_file_net_dispose() is the consumer side of l->freeme: the nfsd
service thread loop calls it to drain entries that the filecache
garbage collector and shrinker append via
nfsd_file_dispose_list_delayed().  During per-net teardown,
nn->nfsd_serv is cleared before the filecache laundrette is shut
down, so the service thread can still run a dispose pass that finds
more than eight entries on l->freeme and dereferences a NULL
svc_serv:

    nfsd service thread loop
      nfsd_file_net_dispose(nn)
        if (!list_empty(&l->freeme)) {
            ...
            svc_wake_up(nn->nfsd_serv);   /* nn->nfsd_serv == NULL */
        }

The sibling helper nfsd_file_dispose_list_delayed() already documents
this ordering and caches nn->nfsd_serv into a local before testing it
for NULL.  nfsd_file_net_dispose() was introduced with the same raw
svc_wake_up(nn->nfsd_serv) call and never picked up the guard.

Fix by loading nn->nfsd_serv into a local svc_serv pointer and only
calling svc_wake_up() when it is non-NULL, matching the pattern in
nfsd_file_dispose_list_delayed().

## Remediation

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