CVE-2026-53394 (GCVE-0-2026-53394)

Vulnerability from cvelistv5 – Published: 2026-07-19 12:01 – Updated: 2026-07-20 13:39
VLAI
Title
nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race
Summary
In the Linux kernel, the following vulnerability has been resolved: nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race When find_or_alloc_open_stateowner() encounters an unconfirmed owner, it calls release_openowner() and sets oo = NULL. Control then falls through past the `if (oo)` guard -- which would have freed any pre-allocated `new` -- and unconditionally executes `new = alloc_stateowner(...)`. If `new` was already allocated on a prior iteration, the pointer is silently overwritten and the previous allocation (slab object + owner name buffer) is leaked. This requires a race: two NFSv4.0 OPEN threads with the same owner string, where a concurrent thread inserts a new unconfirmed owner into the hash between retry iterations. The window is narrow but repeatable under adversarial conditions. Fix by adding `goto retry` after `oo = NULL` so the already-allocated `new` is reused on the next iteration rather than overwritten.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 23df17788c6212809848f836b10c4f85b16843a5 , < c9aefb2b5f11337c9202c5bd0c45d71198449718 (git)
Affected: 23df17788c6212809848f836b10c4f85b16843a5 , < 017a6150106b054cc84d1b0582d97bd3a74d4281 (git)
Affected: 23df17788c6212809848f836b10c4f85b16843a5 , < a10bf67fe06469a71a401f72f328237345d553c0 (git)
Affected: 23df17788c6212809848f836b10c4f85b16843a5 , < 57aee7a35bb12753057c5b65d72d1f46c0e95b07 (git)
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Linux Linux Affected: 6.10
Unaffected: 0 , < 6.10 (semver)
Unaffected: 6.12.95 , ≤ 6.12.* (semver)
Unaffected: 6.18.38 , ≤ 6.18.* (semver)
Unaffected: 7.1.3 , ≤ 7.1.* (semver)
Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)
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    "dateReserved": "2026-06-09T07:44:35.402Z",
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-20T15:34:20+00:00",
      "cve": "CVE-2026-53394",
      "id": "CVE-2026-53394",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_affected": "198",
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      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53394.json",
      "version": "3"
    }
  }
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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