---
id: CVE-2026-53396
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: fix posix_acl leak and ignored error in nfsd4_create_file

  nfsd4_create_file() has two bugs in its ACL handling:

  The return value of nfsd4_acl_to_attr() is silen…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: fix posix_acl leak and ignored error in nfsd4_create_file

  nfsd4_create_file() has two bugs in its ACL handling:

  The return value of nfsd4_acl_to_attr() is silen…
severity: none
published: '2026-07-19'
updated: '2026-07-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53396'
references:
  - url: 'https://git.kernel.org/stable/c/18cf006a08babec0bbac2a3784f8f28e56e47490'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/24c975bbdd564d7d0ad90294bfa69729830345de'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
ingestedAt: '2026-07-19T21:33:34.925Z'
epss: 0.0038
epssPercentile: 0.31887
---

## Overview

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

nfsd: fix posix_acl leak and ignored error in nfsd4_create_file

nfsd4_create_file() has two bugs in its ACL handling:

The return value of nfsd4_acl_to_attr() is silently discarded.  When
the NFSv4-to-POSIX ACL conversion fails (e.g., -EINVAL for
unsupported ACE types), the file is created without any ACL and the
client receives NFS4_OK.  This violates RFC 7530/8881 which require
the server to reject unsupported attributes on CREATE.

When start_creating() fails after ACL attributes have been populated
in attrs (either via nfsd4_acl_to_attr or via ownership transfer from
open->op_dpacl/op_pacl), the function jumps to out_write which skips
nfsd_attrs_free().  The posix_acl allocations are leaked.  A client
can trigger this repeatedly with OPEN(CREATE), ACL attributes, and an
invalid filename (e.g., longer than NAME_MAX).

Fix both by capturing the nfsd4_acl_to_attr() return value and by
changing the early error paths to jump to out instead of out_write.
Initialize child to ERR_PTR(-EINVAL) so that end_creating() is safe
to call even if start_creating() was never reached.

## Remediation

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