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

Vulnerability from cvelistv5 – Published: 2026-07-19 12:01 – Updated: 2026-08-05 12:35
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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If\\n`new` was already allocated on a prior iteration, the pointer is\\nsilently overwritten and the previous allocation (slab object + owner\\nname buffer) is leaked.\\n\\nThis requires a race: two NFSv4.0 OPEN threads with the same owner\\nstring, where a concurrent thread inserts a new unconfirmed owner into\\nthe hash between retry iterations. The window is narrow but repeatable\\nunder adversarial conditions.\\n\\nFix by adding `goto retry` after `oo = NULL` so the already-allocated\\n`new` is reused on the next iteration rather than overwritten.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/nfsd/nfs4state.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"23df17788c6212809848f836b10c4f85b16843a5\",\"lessThan\":\"c9aefb2b5f11337c9202c5bd0c45d71198449718\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23df17788c6212809848f836b10c4f85b16843a5\",\"lessThan\":\"017a6150106b054cc84d1b0582d97bd3a74d4281\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23df17788c6212809848f836b10c4f85b16843a5\",\"lessThan\":\"a10bf67fe06469a71a401f72f328237345d553c0\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23df17788c6212809848f836b10c4f85b16843a5\",\"lessThan\":\"57aee7a35bb12753057c5b65d72d1f46c0e95b07\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/nfsd/nfs4state.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.10\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.10\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.95\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.38\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.3\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-401\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.10\",\"versionEndExcluding\":\"6.12.95\",\"matchCriteriaId\":\"F3CCEC80-8582-4B49-B505-8BCECAFA4CE9\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.18.38\",\"matchCriteriaId\":\"FA591B28-5D62-449E-BDBE-3C9391BF070A\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.19\",\"versionEndExcluding\":\"7.1.3\",\"matchCriteriaId\":\"9526B150-E2B3-4C6F-8AE5-1AF92B75AD9E\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/017a6150106b054cc84d1b0582d97bd3a74d4281\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/57aee7a35bb12753057c5b65d72d1f46c0e95b07\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/a10bf67fe06469a71a401f72f328237345d553c0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/c9aefb2b5f11337c9202c5bd0c45d71198449718\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "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",
      "product_status:known_not_affected": "77",
      "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"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-07T23:48:53Z",
      "cve": "CVE-2026-53394",
      "id": "CVE-2026-53394",
      "initial_release_date": "2026-07-19T17:36:03Z",
      "product_status:known_affected": "17",
      "product_status:known_not_affected": "267",
      "product_status:recommended": "4",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-53394",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-53394.json",
      "version": "5"
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}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • 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.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • 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.


Detection rules are retrieved from Rulezet.