FKIE_CVE-2026-64537
Vulnerability from fkie_nvd - Published: 2026-07-27 21:17 - Updated: 2026-07-27 21:17
Severity
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).
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/bridge/br_cfm.c",
"net/bridge/br_cfm_netlink.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "2870056a78961e0fecd652362ee9d3fcfd24a8a6",
"status": "affected",
"version": "2be665c3940d367e0a2a8128eb4985ce323f99a3",
"versionType": "git"
},
{
"lessThan": "f0f5eb59a97ece0d85de8cfa95dc18c609302a8b",
"status": "affected",
"version": "2be665c3940d367e0a2a8128eb4985ce323f99a3",
"versionType": "git"
},
{
"lessThan": "53788b134519e995699ea3721969c96a08d64575",
"status": "affected",
"version": "2be665c3940d367e0a2a8128eb4985ce323f99a3",
"versionType": "git"
},
{
"lessThan": "b42aeb58317f12024734759ff745856b53948873",
"status": "affected",
"version": "2be665c3940d367e0a2a8128eb4985ce323f99a3",
"versionType": "git"
},
{
"lessThan": "a090880c1f544589427e5b7050c40fb211ccecb4",
"status": "affected",
"version": "2be665c3940d367e0a2a8128eb4985ce323f99a3",
"versionType": "git"
},
{
"lessThan": "865643640b5b5c4579b32d7a55ac9ad648362eaa",
"status": "affected",
"version": "2be665c3940d367e0a2a8128eb4985ce323f99a3",
"versionType": "git"
},
{
"lessThan": "f3e02edd8322b31b8e6517faa6ba053bf29d1e26",
"status": "affected",
"version": "2be665c3940d367e0a2a8128eb4985ce323f99a3",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/bridge/br_cfm.c",
"net/bridge/br_cfm_netlink.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.11"
},
{
"lessThan": "5.11",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"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)."
}
],
"id": "CVE-2026-64537",
"lastModified": "2026-07-27T21:17:05.987",
"metrics": {},
"published": "2026-07-27T21:17:05.987",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2870056a78961e0fecd652362ee9d3fcfd24a8a6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/53788b134519e995699ea3721969c96a08d64575"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/865643640b5b5c4579b32d7a55ac9ad648362eaa"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a090880c1f544589427e5b7050c40fb211ccecb4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b42aeb58317f12024734759ff745856b53948873"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f0f5eb59a97ece0d85de8cfa95dc18c609302a8b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f3e02edd8322b31b8e6517faa6ba053bf29d1e26"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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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
| 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.
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- 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.
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