Vulnerability-Lookup

GHSA-9HMP-J3GC-JM6J

Vulnerability from github – Published: 2026-06-24 09:30 – Updated: 2026-06-24 09:30

Details

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

crypto: jitterentropy - replace long-held spinlock with mutex

jent_kcapi_random() serializes the shared jitterentropy state, but it currently holds a spinlock across the jent_read_entropy() call. That path performs expensive jitter collection and SHA3 conditioning, so parallel readers can trigger stalls as contending waiters spin for the same lock.

To prevent non-preemptible lock hold, replace rng->jent_lock with a mutex so contended readers sleep instead of spinning on a shared lock held across expensive entropy generation.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-52936"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-24T08:16:23Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: jitterentropy - replace long-held spinlock with mutex\n\njent_kcapi_random() serializes the shared jitterentropy state, but it\ncurrently holds a spinlock across the jent_read_entropy() call. That\npath performs expensive jitter collection and SHA3 conditioning, so\nparallel readers can trigger stalls as contending waiters spin for\nthe same lock.\n\nTo prevent non-preemptible lock hold, replace rng-\u003ejent_lock with a\nmutex so contended readers sleep instead of spinning on a shared lock\nheld across expensive entropy generation.",
  "id": "GHSA-9hmp-j3gc-jm6j",
  "modified": "2026-06-24T09:30:48Z",
  "published": "2026-06-24T09:30:48Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-52936"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/01d798e9feb30212952d4e992801ba6bd6a82351"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/18216b8ab6904753eaf31baf453cb02ecd202ba4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4c03e6eb98443dc4d6d422a9780034a5b75376b4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ec427dc5286da1ed08f2d510e2147a7581b0cb02"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ff734dbd9e2432601a6dcd167cfb0bf8a36d1880"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-52936 (GCVE-0-2026-52936)

Vulnerability from cvelistv5 – Published: 2026-06-24 07:14 – Updated: 2026-06-24 07:14

Title

crypto: jitterentropy - replace long-held spinlock with mutex

Summary

In the Linux kernel, the following vulnerability has been resolved: crypto: jitterentropy - replace long-held spinlock with mutex jent_kcapi_random() serializes the shared jitterentropy state, but it currently holds a spinlock across the jent_read_entropy() call. That path performs expensive jitter collection and SHA3 conditioning, so parallel readers can trigger stalls as contending waiters spin for the same lock. To prevent non-preemptible lock hold, replace rng->jent_lock with a mutex so contended readers sleep instead of spinning on a shared lock held across expensive entropy generation.

Severity

No CVSS data available.

Assigner

Linux

References

5 references

URL	Tags
https://git.kernel.org/stable/c/18216b8ab6904753e…
https://git.kernel.org/stable/c/4c03e6eb98443dc4d…
https://git.kernel.org/stable/c/ff734dbd9e2432601…
https://git.kernel.org/stable/c/ec427dc5286da1ed0…
https://git.kernel.org/stable/c/01d798e9feb302129…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: bb5530e4082446aac3a3d69780cd4dbfa4520013 , < 18216b8ab6904753eaf31baf453cb02ecd202ba4 (git) Affected: bb5530e4082446aac3a3d69780cd4dbfa4520013 , < 4c03e6eb98443dc4d6d422a9780034a5b75376b4 (git) Affected: bb5530e4082446aac3a3d69780cd4dbfa4520013 , < ff734dbd9e2432601a6dcd167cfb0bf8a36d1880 (git) Affected: bb5530e4082446aac3a3d69780cd4dbfa4520013 , < ec427dc5286da1ed08f2d510e2147a7581b0cb02 (git) Affected: bb5530e4082446aac3a3d69780cd4dbfa4520013 , < 01d798e9feb30212952d4e992801ba6bd6a82351 (git)
Linux	Linux	Affected: 4.2 Unaffected: 0 , < 4.2 (semver) Unaffected: 6.6.141 , ≤ 6.6.* (semver) Unaffected: 6.12.91 , ≤ 6.12.* (semver) Unaffected: 6.18.33 , ≤ 6.18.* (semver) Unaffected: 7.0.10 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "crypto/jitterentropy-kcapi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "18216b8ab6904753eaf31baf453cb02ecd202ba4",
              "status": "affected",
              "version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
              "versionType": "git"
            },
            {
              "lessThan": "4c03e6eb98443dc4d6d422a9780034a5b75376b4",
              "status": "affected",
              "version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
              "versionType": "git"
            },
            {
              "lessThan": "ff734dbd9e2432601a6dcd167cfb0bf8a36d1880",
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              "versionType": "git"
            },
            {
              "lessThan": "ec427dc5286da1ed08f2d510e2147a7581b0cb02",
              "status": "affected",
              "version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
              "versionType": "git"
            },
            {
              "lessThan": "01d798e9feb30212952d4e992801ba6bd6a82351",
              "status": "affected",
              "version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "crypto/jitterentropy-kcapi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.2"
            },
            {
              "lessThan": "4.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.141",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.91",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.33",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.141",
                  "versionStartIncluding": "4.2",
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                },
                {
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: jitterentropy - replace long-held spinlock with mutex\n\njent_kcapi_random() serializes the shared jitterentropy state, but it\ncurrently holds a spinlock across the jent_read_entropy() call. That\npath performs expensive jitter collection and SHA3 conditioning, so\nparallel readers can trigger stalls as contending waiters spin for\nthe same lock.\n\nTo prevent non-preemptible lock hold, replace rng-\u003ejent_lock with a\nmutex so contended readers sleep instead of spinning on a shared lock\nheld across expensive entropy generation."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-24T07:14:26.649Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/18216b8ab6904753eaf31baf453cb02ecd202ba4"
        },
        {
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        },
        {
          "url": "https://git.kernel.org/stable/c/ff734dbd9e2432601a6dcd167cfb0bf8a36d1880"
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        {
          "url": "https://git.kernel.org/stable/c/ec427dc5286da1ed08f2d510e2147a7581b0cb02"
        },
        {
          "url": "https://git.kernel.org/stable/c/01d798e9feb30212952d4e992801ba6bd6a82351"
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      ],
      "title": "crypto: jitterentropy - replace long-held spinlock with mutex",
      "x_generator": {
        "engine": "bippy-1.2.0"
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-52936",
    "datePublished": "2026-06-24T07:14:26.649Z",
    "dateReserved": "2026-06-09T07:44:35.370Z",
    "dateUpdated": "2026-06-24T07:14:26.649Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

Action not permitted

GHSA-9HMP-J3GC-JM6J

CVE-2026-52936 (GCVE-0-2026-52936)

Tags

Sightings

Nomenclature