---
id: CVE-2026-53397
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: fix posix_acl leak on SETACL decode failure

  nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each
  call nfs_stream_decode_acl() twice, first for NFS_…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: fix posix_acl leak on SETACL decode failure

  nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each
  call nfs_stream_decode_acl() twice, first for NFS_…
severity: high
published: '2026-07-19'
updated: '2026-07-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53397'
references:
  - url: 'https://git.kernel.org/stable/c/0853ac544c590880d797b04daa33fcb72b6be0e1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/136b416593f1349cf6f72c8e3d18f0f204ee8545'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1e96239fddcefacf6afe6c498357be68eacbcabc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/887f92ceccf3eacd5f2402db21254d66372fae00'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a5b42c1e4ff2befaa6b96f7cbf32174751eba083'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b2eb1ffd511d1b3c3e21122f97cbbccea411e277'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b94c4be77682aab06d65ca7296149e3bcfb37353'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/bd69a825485168ef74e815ecb286754b570fdcc7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-07-19T21:33:34.946Z'
epss: 0.00529
epssPercentile: 0.44554
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 <
    b2eb1ffd511d1b3c3e21122f97cbbccea411e277
  - >-
    Linux >= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 <
    b94c4be77682aab06d65ca7296149e3bcfb37353
  - >-
    Linux >= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 <
    887f92ceccf3eacd5f2402db21254d66372fae00
  - >-
    Linux >= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 <
    1e96239fddcefacf6afe6c498357be68eacbcabc
  - >-
    Linux >= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 <
    bd69a825485168ef74e815ecb286754b570fdcc7
  - >-
    Linux >= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 <
    136b416593f1349cf6f72c8e3d18f0f204ee8545
  - >-
    Linux >= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 <
    a5b42c1e4ff2befaa6b96f7cbf32174751eba083
  - >-
    Linux >= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 <
    0853ac544c590880d797b04daa33fcb72b6be0e1
  - Linux 2.6.13
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-16T15:30:22.806921Z'
cvssSource: cna
---

## Overview

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

nfsd: fix posix_acl leak on SETACL decode failure

nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each
call nfs_stream_decode_acl() twice, first for NFS_ACL and then for
NFS_DFACL.  Each successful call transfers ownership of a freshly
allocated posix_acl into argp->acl_access or argp->acl_default.  If
the first call succeeds but the second fails, the decoder returns
false and argp->acl_access is left dangling.

ACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and
ACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle.
Both only call fh_put() and have no knowledge of the ACL fields on
argp.  The posix_acl_release() pairs sat at the out: labels inside
nfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process()
skips pc_func when pc_decode returns false, so that cleanup is
unreachable on decode failure:

    svc_process_common()
      pc_decode()                  /* decode_setaclargs: false */
      /* pc_func skipped */
      pc_release()                 /* fh_put only -- ACLs leaked */

The orphaned posix_acl is leaked for the lifetime of the server.

Fix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(),
which release both argp->acl_access and argp->acl_default in addition
to fh_put(), and wiring them as pc_release for their respective SETACL
procedures.  pc_release runs on every path svc_process() takes after
decode, including decode failure, so the posix_acl_release() pairs are
removed from the proc functions' out: labels to keep ownership in one
place.  This matches the existing release_getacl() pattern used by
the sibling GETACL procedures.

## Remediation

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