github - ghsa-rh5v-2xrc-gj9x

GHSA-RH5V-2XRC-GJ9X

Vulnerability from github – Published: 2025-09-11 18:35 – Updated: 2025-11-25 21:32

Details

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

netfilter: ctnetlink: remove refcounting in expectation dumpers

Same pattern as previous patch: do not keep the expectation object alive via refcount, only store a cookie value and then use that as the skip hint for dump resumption.

AFAICS this has the same issue as the one resolved in the conntrack dumper, when we do if (!refcount_inc_not_zero(&exp->use))

to increment the refcount, there is a chance that exp == last, which causes a double-increment of the refcount and subsequent memory leak.

Severity ?

5.5 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2025-39764"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-09-11T17:15:40Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: remove refcounting in expectation dumpers\n\nSame pattern as previous patch: do not keep the expectation object\nalive via refcount, only store a cookie value and then use that\nas the skip hint for dump resumption.\n\nAFAICS this has the same issue as the one resolved in the conntrack\ndumper, when we do\n  if (!refcount_inc_not_zero(\u0026exp-\u003euse))\n\nto increment the refcount, there is a chance that exp == last, which\ncauses a double-increment of the refcount and subsequent memory leak.",
  "id": "GHSA-rh5v-2xrc-gj9x",
  "modified": "2025-11-25T21:32:04Z",
  "published": "2025-09-11T18:35:52Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-39764"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1492e3dcb2be3aa46d1963da96aa9593e4e4db5a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a4d634ded4d3d400f115d84f654f316f249531c9"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2025-39764 (GCVE-0-2025-39764)

Vulnerability from cvelistv5 – Published: 2025-09-11 16:52 – Updated: 2025-09-29 05:58

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: ctnetlink: remove refcounting in expectation dumpers Same pattern as previous patch: do not keep the expectation object alive via refcount, only store a cookie value and then use that as the skip hint for dump resumption. AFAICS this has the same issue as the one resolved in the conntrack dumper, when we do if (!refcount_inc_not_zero(&exp->use)) to increment the refcount, there is a chance that exp == last, which causes a double-increment of the refcount and subsequent memory leak.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/a4d634ded4d3d400f…
	https://git.kernel.org/stable/c/1492e3dcb2be3aa46…

Impacted products

Vendor

Product

Version

Linux

Affected: cf6994c2b9812a9f02b99e89df411ffc5db9c779 , < a4d634ded4d3d400f115d84f654f316f249531c9 (git)
Affected: cf6994c2b9812a9f02b99e89df411ffc5db9c779 , < 1492e3dcb2be3aa46d1963da96aa9593e4e4db5a (git)

Linux

Affected: 2.6.23
Unaffected: 0 , < 2.6.23 (semver)
Unaffected: 6.16.2 , ≤ 6.16.* (semver)
Unaffected: 6.17 , ≤ * (original_commit_for_fix)

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  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nf_conntrack_netlink.c"
          ],
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          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a4d634ded4d3d400f115d84f654f316f249531c9",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "1492e3dcb2be3aa46d1963da96aa9593e4e4db5a",
              "status": "affected",
              "version": "cf6994c2b9812a9f02b99e89df411ffc5db9c779",
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          "versions": [
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            },
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.16.*",
              "status": "unaffected",
              "version": "6.16.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.17",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: remove refcounting in expectation dumpers\n\nSame pattern as previous patch: do not keep the expectation object\nalive via refcount, only store a cookie value and then use that\nas the skip hint for dump resumption.\n\nAFAICS this has the same issue as the one resolved in the conntrack\ndumper, when we do\n  if (!refcount_inc_not_zero(\u0026exp-\u003euse))\n\nto increment the refcount, there is a chance that exp == last, which\ncauses a double-increment of the refcount and subsequent memory leak."
        }
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      "providerMetadata": {
        "dateUpdated": "2025-09-29T05:58:56.459Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    "cveId": "CVE-2025-39764",
    "datePublished": "2025-09-11T16:52:32.060Z",
    "dateReserved": "2025-04-16T07:20:57.126Z",
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}

Sightings

Author	Source	Type	Date

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-RH5V-2XRC-GJ9X

CVE-2025-39764 (GCVE-0-2025-39764)

Tags

Sightings

Nomenclature