FKIE_CVE-2026-89569
Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-14 13:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: serialize security confirmation handling
rfcomm_security_cfm() looks up a session on session_list and then walks
its DLC list without holding rfcomm_mutex. Since RFCOMM session teardown
uses rfcomm_mutex, krfcommd can close and free the same session and DLCs
concurrently:
hci_rx_work krfcommd
----------- ---------
rfcomm_session_get()
rfcomm_lock()
rfcomm_session_close()
rfcomm_dlc_unlink()
rfcomm_session_del()
kfree(s)
rfcomm_unlock()
walk s->dlcs
The callback can then read a freed session list head and touch freed DLCs
while updating their flags or timers.
Serialize the session lookup and DLC traversal in rfcomm_security_cfm()
with rfcomm_mutex. This matches the existing RFCOMM session lifetime
rules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink()
from tearing the objects down while the callback is using them.
KASAN reported:
BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440
Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89
Workqueue: hci0 hci_rx_work
Call Trace:
rfcomm_security_cfm+0x41c/0x440
hci_encrypt_cfm+0x139/0x590
hci_encrypt_change_evt+0x37b/0xc40
hci_event_packet+0x71b/0xb20
hci_rx_work+0x293/0x730
Allocated by task 69:
rfcomm_session_add+0x9e/0x2f0
rfcomm_run+0x44b/0x41e0
Freed by task 69:
kfree+0x131/0x3c0
rfcomm_session_del+0x188/0x220
rfcomm_run+0x1985/0x41e0
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/bluetooth/rfcomm/core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "62ce8b33eb238cf18c15207332fbdc26d858f592",
"status": "affected",
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"versionType": "git"
},
{
"lessThan": "3873f3449701b3dc98cba577923be6493598e7a1",
"status": "affected",
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"versionType": "git"
},
{
"lessThan": "7ded3264106418c6456ccceaafd9fda596ce12c3",
"status": "affected",
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"versionType": "git"
},
{
"lessThan": "82425b14f0fb22e46cfddc56d6465570f5ed0ce6",
"status": "affected",
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"versionType": "git"
},
{
"lessThan": "1b7841ffad08e911e8c4b9470f3fa08423568940",
"status": "affected",
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"versionType": "git"
},
{
"lessThan": "946d76db77ee5f922968ce558629ae47b381e3fc",
"status": "affected",
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"versionType": "git"
},
{
"lessThan": "fbf7961964a6e93360179f64712320ae9a1e9577",
"status": "affected",
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"versionType": "git"
},
{
"lessThan": "759c185d0bbdb131357408f50b8735e04ed3caff",
"status": "affected",
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/bluetooth/rfcomm/core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.10"
},
{
"lessThan": "3.10",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-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\nBluetooth: RFCOMM: serialize security confirmation handling\n\nrfcomm_security_cfm() looks up a session on session_list and then walks\nits DLC list without holding rfcomm_mutex. Since RFCOMM session teardown\nuses rfcomm_mutex, krfcommd can close and free the same session and DLCs\nconcurrently:\n\n hci_rx_work krfcommd\n ----------- ---------\n rfcomm_session_get()\n rfcomm_lock()\n rfcomm_session_close()\n rfcomm_dlc_unlink()\n rfcomm_session_del()\n kfree(s)\n rfcomm_unlock()\n walk s-\u003edlcs\n\nThe callback can then read a freed session list head and touch freed DLCs\nwhile updating their flags or timers.\n\nSerialize the session lookup and DLC traversal in rfcomm_security_cfm()\nwith rfcomm_mutex. This matches the existing RFCOMM session lifetime\nrules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink()\nfrom tearing the objects down while the callback is using them.\n\nKASAN reported:\n\n BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440\n Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89\n Workqueue: hci0 hci_rx_work\n Call Trace:\n rfcomm_security_cfm+0x41c/0x440\n hci_encrypt_cfm+0x139/0x590\n hci_encrypt_change_evt+0x37b/0xc40\n hci_event_packet+0x71b/0xb20\n hci_rx_work+0x293/0x730\n Allocated by task 69:\n rfcomm_session_add+0x9e/0x2f0\n rfcomm_run+0x44b/0x41e0\n Freed by task 69:\n kfree+0x131/0x3c0\n rfcomm_session_del+0x188/0x220\n rfcomm_run+0x1985/0x41e0"
}
],
"id": "CVE-2026-89569",
"lastModified": "2026-09-14T13:19:11.727",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "ADJACENT_NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-09-11T20:19:40.920",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1b7841ffad08e911e8c4b9470f3fa08423568940"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3873f3449701b3dc98cba577923be6493598e7a1"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/62ce8b33eb238cf18c15207332fbdc26d858f592"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/759c185d0bbdb131357408f50b8735e04ed3caff"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7ded3264106418c6456ccceaafd9fda596ce12c3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/82425b14f0fb22e46cfddc56d6465570f5ed0ce6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/946d76db77ee5f922968ce558629ae47b381e3fc"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/fbf7961964a6e93360179f64712320ae9a1e9577"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
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.
- 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.
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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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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