CVE-2024-53186
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in SMB request handling
A race condition exists between SMB request handling in `ksmbd_conn_handler_loop()` and the freeing of `ksmbd_conn` in the workqueue handler `handle_ksmbd_work()`. This leads to a UAF. - KASAN: slab-use-after-free Read in handle_ksmbd_work - KASAN: slab-use-after-free in rtlock_slowlock_locked
The discovery of this UAF can be referenced in the following PR for syzkaller's support for SMB requests.
Detalles técnicos trazas, registros y código del informe original
This race condition arises as follows: - `ksmbd_conn_handler_loop()` waits for `conn->r_count` to reach zero: `wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);` - Meanwhile, `handle_ksmbd_work()` decrements `conn->r_count` using `atomic_dec_return(&conn->r_count)`, and if it reaches zero, calls `ksmbd_conn_free()`, which frees `conn`. - However, after `handle_ksmbd_work()` decrements `conn->r_count`, it may still access `conn->r_count_q` in the following line: `waitqueue_active(&conn->r_count_q)` or `wake_up(&conn->r_count_q)` This results in a UAF, as `conn` has already been freed.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.46%
- Percentil entre todas las CVEs puntuadas: 37
- 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
T1068Exploitation for Privilege Escalationprivilege escalation75 % - Impacto secundario
T1059Command and Scripting Interpreterexecution60 %
Vulnerabilidad local (AV:L, PR:L) de UAF en ksmbd que permite escalada de privilegios. La carrera de datos entre `ksmbd_conn_handler_loop()` y `handle_ksmbd_work()` facilita ejecución de código con privilegios elevados tras explotar la condición de carrera.
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)
CWE
- CWE-362, CWE-416
- CWE-416
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2024-53186",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2024-53186",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2025-02-10T17:13:00.740506Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.8,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/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": 3.9
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1
},
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"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": "18f06bacc197d4ac9b518ad1c69999bc3d83e7aa",
"lessThan": "a96f9eb7add30ba0fafcfe7b7aca090978196800",
"versionType": "git"
},
{
"status": "affected",
"version": "e9dac92f4482a382e8c0fe1bc243da5fc3526b0c",
"lessThan": "f20b77f7897e6aab9ce5527e6016ad2be5d70a33",
"versionType": "git"
},
{
"status": "affected",
"version": "ee426bfb9d09b29987369b897fe9b6485ac2be27",
"lessThan": "96261adb998a3b513468b6ce17dbec76be5507d4",
"versionType": "git"
},
{
"status": "affected",
"version": "ee426bfb9d09b29987369b897fe9b6485ac2be27",
"lessThan": "9a8c5d89d327ff58e9b2517f8a6afb4181d32c6e",
"versionType": "git"
},
{
"status": "affected",
"version": "9fd3cde4628bcd3549ab95061f2bab74d2ed4f3b",
"versionType": "git"
},
{
"status": "affected",
"version": "6.6.55",
"lessThan": "6.6.64",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.11.3",
"lessThan": "6.11.11",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.10.14",
"lessThan": "6.11",
"versionType": "semver"
}
],
"programFiles": [
"fs/smb/server/server.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.12"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.12",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.64",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.11.11",
"versionType": "semver",
"lessThanOrEqual": "6.11.*"
},
{
"status": "unaffected",
"version": "6.12.2",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.13",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/server/server.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2024-12-27T14:15:26.083",
"references": [
{
"url": "https://git.kernel.org/stable/c/96261adb998a3b513468b6ce17dbec76be5507d4",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9a8c5d89d327ff58e9b2517f8a6afb4181d32c6e",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a96f9eb7add30ba0fafcfe7b7aca090978196800",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f20b77f7897e6aab9ce5527e6016ad2be5d70a33",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-362"
},
{
"lang": "en",
"value": "CWE-416"
}
]
},
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"description": [
{
"lang": "en",
"value": "CWE-416"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in SMB request handling\n\nA race condition exists between SMB request handling in\n`ksmbd_conn_handler_loop()` and the freeing of `ksmbd_conn` in the\nworkqueue handler `handle_ksmbd_work()`. This leads to a UAF.\n- KASAN: slab-use-after-free Read in handle_ksmbd_work\n- KASAN: slab-use-after-free in rtlock_slowlock_locked\n\nThis race condition arises as follows:\n- `ksmbd_conn_handler_loop()` waits for `conn->r_count` to reach zero:\n `wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);`\n- Meanwhile, `handle_ksmbd_work()` decrements `conn->r_count` using\n `atomic_dec_return(&conn->r_count)`, and if it reaches zero, calls\n `ksmbd_conn_free()`, which frees `conn`.\n- However, after `handle_ksmbd_work()` decrements `conn->r_count`,\n it may still access `conn->r_count_q` in the following line:\n `waitqueue_active(&conn->r_count_q)` or `wake_up(&conn->r_count_q)`\n This results in a UAF, as `conn` has already been freed.\n\nThe discovery of this UAF can be referenced in the following PR for\nsyzkaller's support for SMB requests."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ksmbd: se corrige el problema de use-after-free en la gestión de solicitudes SMB Existe una condición de ejecución entre la gestión de solicitudes SMB en `ksmbd_conn_handler_loop()` y la liberación de `ksmbd_conn` en el controlador de cola de trabajo `handle_ksmbd_work()`. Esto conduce a una UAF. - KASAN: slab-use-after-free Leer en handle_ksmbd_work - KASAN: slab-use-after-free en rtlock_slowlock_locked Esta condición de ejecución surge de la siguiente manera: - `ksmbd_conn_handler_loop()` espera a que `conn->r_count` llegue a cero: `wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);` - Mientras tanto, `handle_ksmbd_work()` decrementa `conn->r_count` usando `atomic_dec_return(&conn->r_count)`, y si llega a cero, llama a `ksmbd_conn_free()`, que libera a `conn`. - Sin embargo, después de que `handle_ksmbd_work()` disminuya `conn->r_count`, aún puede acceder a `conn->r_count_q` en la siguiente línea: `waitqueue_active(&conn->r_count_q)` o `wake_up(&conn->r_count_q)` Esto da como resultado un UAF, ya que `conn` ya se ha liberado. Se puede hacer referencia al descubrimiento de este UAF en la siguiente PR para el soporte de syzkaller para solicitudes SMB."
}
],
"lastModified": "2026-08-04T11:22:03.150",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "C813C628-8D83-4585-9CCE-3DE13EBB4454",
"versionEndExcluding": "6.6.64",
"versionStartIncluding": "6.6.55"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "41AB04F0-1096-4B39-8148-796AB65AA193",
"versionEndExcluding": "6.11",
"versionStartIncluding": "6.10.14"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "C2F1D9BC-CB2F-488F-90F8-8456CD3C44CB",
"versionEndExcluding": "6.11.11",
"versionStartIncluding": "6.11.3"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D8882B1B-2ABC-4838-AC1D-DBDBB5764776",
"versionEndExcluding": "6.12.2",
"versionStartIncluding": "6.12"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}