Vulnerability-Lookup

CVE-2026-64537 (GCVE-0-2026-64537)

Vulnerability from cvelistv5 – Published: 2026-07-27 20:10 – Updated: 2026-07-27 20:10

Title

bridge: cfm: reject invalid CCM interval at configuration time

Summary

In the Linux kernel, the following vulnerability has been resolved: bridge: cfm: reject invalid CCM interval at configuration time ccm_tx_work_expired() re-arms itself via queue_delayed_work() using the configured exp_interval converted by interval_to_us(). When exp_interval is BR_CFM_CCM_INTERVAL_NONE or out of range, interval_to_us() returns 0, causing the worker to fire immediately in a tight loop that allocates skbs until OOM. Fix this by validating exp_interval at configuration time: - Constrain IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL to the valid range [BR_CFM_CCM_INTERVAL_3_3_MS, BR_CFM_CCM_INTERVAL_10_MIN] in the netlink policy so userspace cannot set an invalid value. - Reject starting CCM TX in br_cfm_cc_ccm_tx() when exp_interval has not yet been configured (defaults to 0 from kzalloc).

Severity

No CVSS data available.

Assigner

Linux

References

7 references

URL	Tags
https://git.kernel.org/stable/c/2870056a78961e0fe…
https://git.kernel.org/stable/c/f0f5eb59a97ece0d8…
https://git.kernel.org/stable/c/53788b134519e9956…
https://git.kernel.org/stable/c/b42aeb58317f12024…
https://git.kernel.org/stable/c/a090880c1f5445894…
https://git.kernel.org/stable/c/865643640b5b5c457…
https://git.kernel.org/stable/c/f3e02edd8322b31b8…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 2be665c3940d367e0a2a8128eb4985ce323f99a3 , < 2870056a78961e0fecd652362ee9d3fcfd24a8a6 (git) Affected: 2be665c3940d367e0a2a8128eb4985ce323f99a3 , < f0f5eb59a97ece0d85de8cfa95dc18c609302a8b (git) Affected: 2be665c3940d367e0a2a8128eb4985ce323f99a3 , < 53788b134519e995699ea3721969c96a08d64575 (git) Affected: 2be665c3940d367e0a2a8128eb4985ce323f99a3 , < b42aeb58317f12024734759ff745856b53948873 (git) Affected: 2be665c3940d367e0a2a8128eb4985ce323f99a3 , < a090880c1f544589427e5b7050c40fb211ccecb4 (git) Affected: 2be665c3940d367e0a2a8128eb4985ce323f99a3 , < 865643640b5b5c4579b32d7a55ac9ad648362eaa (git) Affected: 2be665c3940d367e0a2a8128eb4985ce323f99a3 , < f3e02edd8322b31b8e6517faa6ba053bf29d1e26 (git)
Linux	Linux	Affected: 5.11 Unaffected: 0 , < 5.11 (semver) Unaffected: 5.15.212 , ≤ 5.15.* (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

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JSON

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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbridge: cfm: reject invalid CCM interval at configuration time\n\nccm_tx_work_expired() re-arms itself via queue_delayed_work() using\nthe configured exp_interval converted by interval_to_us(). When\nexp_interval is BR_CFM_CCM_INTERVAL_NONE or out of range,\ninterval_to_us() returns 0, causing the worker to fire immediately in\na tight loop that allocates skbs until OOM.\n\nFix this by validating exp_interval at configuration time:\n\n - Constrain IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL to the valid range\n   [BR_CFM_CCM_INTERVAL_3_3_MS, BR_CFM_CCM_INTERVAL_10_MIN] in the\n   netlink policy so userspace cannot set an invalid value.\n\n - Reject starting CCM TX in br_cfm_cc_ccm_tx() when exp_interval has\n   not yet been configured (defaults to 0 from kzalloc)."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-27T20:10:32.210Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/f0f5eb59a97ece0d85de8cfa95dc18c609302a8b"
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          "url": "https://git.kernel.org/stable/c/f3e02edd8322b31b8e6517faa6ba053bf29d1e26"
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    "datePublished": "2026-07-27T20:10:32.210Z",
    "dateReserved": "2026-07-19T15:36:31.795Z",
    "dateUpdated": "2026-07-27T20:10:32.210Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
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  }
}

GHSA-3FRJ-6745-GJX4

Vulnerability from github – Published: 2026-07-27 21:31 – Updated: 2026-07-27 21:31

Details

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

bridge: cfm: reject invalid CCM interval at configuration time

ccm_tx_work_expired() re-arms itself via queue_delayed_work() using the configured exp_interval converted by interval_to_us(). When exp_interval is BR_CFM_CCM_INTERVAL_NONE or out of range, interval_to_us() returns 0, causing the worker to fire immediately in a tight loop that allocates skbs until OOM.

Fix this by validating exp_interval at configuration time:

Constrain IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL to the valid range [BR_CFM_CCM_INTERVAL_3_3_MS, BR_CFM_CCM_INTERVAL_10_MIN] in the netlink policy so userspace cannot set an invalid value.
Reject starting CCM TX in br_cfm_cc_ccm_tx() when exp_interval has not yet been configured (defaults to 0 from kzalloc).

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-64537"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-27T21:17:05Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbridge: cfm: reject invalid CCM interval at configuration time\n\nccm_tx_work_expired() re-arms itself via queue_delayed_work() using\nthe configured exp_interval converted by interval_to_us(). When\nexp_interval is BR_CFM_CCM_INTERVAL_NONE or out of range,\ninterval_to_us() returns 0, causing the worker to fire immediately in\na tight loop that allocates skbs until OOM.\n\nFix this by validating exp_interval at configuration time:\n\n - Constrain IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL to the valid range\n   [BR_CFM_CCM_INTERVAL_3_3_MS, BR_CFM_CCM_INTERVAL_10_MIN] in the\n   netlink policy so userspace cannot set an invalid value.\n\n - Reject starting CCM TX in br_cfm_cc_ccm_tx() when exp_interval has\n   not yet been configured (defaults to 0 from kzalloc).",
  "id": "GHSA-3frj-6745-gjx4",
  "modified": "2026-07-27T21:31:26Z",
  "published": "2026-07-27T21:31:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64537"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2870056a78961e0fecd652362ee9d3fcfd24a8a6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/53788b134519e995699ea3721969c96a08d64575"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/865643640b5b5c4579b32d7a55ac9ad648362eaa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a090880c1f544589427e5b7050c40fb211ccecb4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b42aeb58317f12024734759ff745856b53948873"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f0f5eb59a97ece0d85de8cfa95dc18c609302a8b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f3e02edd8322b31b8e6517faa6ba053bf29d1e26"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-64537 (GCVE-0-2026-64537)

GHSA-3FRJ-6745-GJX4

Tags

Sightings

Nomenclature