CVE-2026-53396 (GCVE-0-2026-53396)

Vulnerability from cvelistv5 – Published: 2026-07-19 12:01 – Updated: 2026-07-20 13:39
VLAI
Title
nfsd: fix posix_acl leak and ignored error in nfsd4_create_file
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 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.
Severity
7.1 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 7ab96df840e60eb933abfe65fc5fe44e72f16dc0 , < 18cf006a08babec0bbac2a3784f8f28e56e47490 (git)
Affected: 7ab96df840e60eb933abfe65fc5fe44e72f16dc0 , < 24c975bbdd564d7d0ad90294bfa69729830345de (git)
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Linux Linux Affected: 6.19
Unaffected: 0 , < 6.19 (semver)
Unaffected: 7.1.3 , ≤ 7.1.* (semver)
Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)
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            "version": "3.1"
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        "dateUpdated": "2026-07-20T13:39:58.755Z",
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        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/24c975bbdd564d7d0ad90294bfa69729830345de"
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    "cveId": "CVE-2026-53396",
    "datePublished": "2026-07-19T12:01:58.375Z",
    "dateReserved": "2026-06-09T07:44:35.402Z",
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    "state": "PUBLISHED"
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    "redhat_vex": {
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      "cve": "CVE-2026-53396",
      "id": "CVE-2026-53396",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_not_affected": "261",
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      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: nfsd: fix posix_acl leak and ignored error in nfsd4_create_file",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53396.json",
      "version": "3"
    }
  }
}



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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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