CVE-2025-68304
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: lookup hci_conn on RX path on protocol side
The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't ensure hci_conn* is not concurrently modified/deleted. This locking appears to be leftover from before conn_hash started using RCU commit bf4c63252490b ("Bluetooth: convert conn hash to RCU") and not clear if it had purpose since then.
Currently, there are code paths that delete hci_conn* from elsewhere than the ordered hdev->workqueue where the RX work runs in.
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E.g. commit 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync") introduced some of these, and there probably were a few others before it. It's better to do the locking so that even if these run concurrently no UAF is possible.
Move the lookup of hci_conn and associated socket-specific conn to protocol recv handlers, and do them within a single critical section to cover hci_conn* usage and lookup.
syzkaller has reported a crash that appears to be this issue:
Detalles técnicos trazas, registros y código del informe original
[Task hdev->workqueue] [Task 2]
hci_disconnect_all_sync
l2cap_recv_acldata(hcon)
hci_conn_get(hcon)
hci_abort_conn_sync(hcon)
hci_dev_lock
hci_dev_lock
hci_conn_del(hcon)
v-------------------------------- hci_dev_unlock
hci_conn_put(hcon)
conn = hcon->l2cap_data (UAF)CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 8.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.23%
- Percentil entre todas las CVEs puntuadas: 13
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1210Exploitation of Remote Serviceslateral movement45 % - Impacto principal
T1499.004Application or System Exploitationimpact70 % - Impacto secundario
T1068Exploitation for Privilege Escalationprivilege escalation35 %
Vulnerabilidad de red adyacente (AV:A) en Bluetooth kernel sin UI. UAF puede causar DoS o escalada; requiere acceso local/adyacente al stack Bluetooth.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2025-68304",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 8.8,
"attackVector": "ADJACENT_NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 2.8
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5af1f84ed13a416297ab9ced7537f4d5ae7f329a",
"lessThan": "ec74cdf77310c43b01b83ee898a9bd4b4b0b8e93",
"versionType": "git"
},
{
"status": "affected",
"version": "5af1f84ed13a416297ab9ced7537f4d5ae7f329a",
"lessThan": "79a2d4678ba90bdba577dc3af88cc900d6dcd5ee",
"versionType": "git"
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{
"status": "affected",
"version": "cd55c13bbb3d093ae601aa97e588ed4c1390ebb1",
"versionType": "git"
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{
"status": "affected",
"version": "4d3ca4a9aaf0aa798a6be372dc0fc3a29e37dd57",
"versionType": "git"
},
{
"status": "affected",
"version": "80265dd1d944c3f33e52375b5dbe654980bd2688",
"versionType": "git"
},
{
"status": "affected",
"version": "6.1.149",
"lessThan": "6.2",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.4.16",
"lessThan": "6.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.5.3",
"lessThan": "6.6",
"versionType": "semver"
}
],
"programFiles": [
"include/net/bluetooth/hci_core.h",
"net/bluetooth/hci_core.c",
"net/bluetooth/iso.c",
"net/bluetooth/l2cap_core.c",
"net/bluetooth/sco.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.6"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.6",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.17.11",
"versionType": "semver",
"lessThanOrEqual": "6.17.*"
},
{
"status": "unaffected",
"version": "6.18",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/net/bluetooth/hci_core.h",
"net/bluetooth/hci_core.c",
"net/bluetooth/iso.c",
"net/bluetooth/l2cap_core.c",
"net/bluetooth/sco.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-12-16T16:16:09.930",
"references": [
{
"url": "https://git.kernel.org/stable/c/79a2d4678ba90bdba577dc3af88cc900d6dcd5ee",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ec74cdf77310c43b01b83ee898a9bd4b4b0b8e93",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: lookup hci_conn on RX path on protocol side\n\nThe hdev lock/lookup/unlock/use pattern in the packet RX path doesn't\nensure hci_conn* is not concurrently modified/deleted. This locking\nappears to be leftover from before conn_hash started using RCU\ncommit bf4c63252490b (\"Bluetooth: convert conn hash to RCU\")\nand not clear if it had purpose since then.\n\nCurrently, there are code paths that delete hci_conn* from elsewhere\nthan the ordered hdev->workqueue where the RX work runs in. E.g.\ncommit 5af1f84ed13a (\"Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync\")\nintroduced some of these, and there probably were a few others before\nit. It's better to do the locking so that even if these run\nconcurrently no UAF is possible.\n\nMove the lookup of hci_conn and associated socket-specific conn to\nprotocol recv handlers, and do them within a single critical section\nto cover hci_conn* usage and lookup.\n\nsyzkaller has reported a crash that appears to be this issue:\n\n [Task hdev->workqueue] [Task 2]\n hci_disconnect_all_sync\n l2cap_recv_acldata(hcon)\n hci_conn_get(hcon)\n hci_abort_conn_sync(hcon)\n hci_dev_lock\n hci_dev_lock\n hci_conn_del(hcon)\n v-------------------------------- hci_dev_unlock\n hci_conn_put(hcon)\n conn = hcon->l2cap_data (UAF)"
}
],
"lastModified": "2026-07-30T06:24:37.587",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}