CVE-2025-38443

Estado: AnalizadaAlta (7.8)—

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

nbd: fix uaf in nbd_genl_connect() error path

There is a use-after-free issue in nbd:

block nbd6: Receive control failed (result -104) block nbd6: shutting down sockets ================================================================== BUG: KASAN: slab-use-after-free in recv_work+0x694/0xa80 drivers/block/nbd.c:1022 Write of size 4 at addr ffff8880295de478 by task kworker/u33:0/67

nbd_genl_connect() does not properly stop the device on certain error paths after nbd_start_device() has been called. This causes the error path to put nbd->config while recv_work continue to use the config after putting it, leading to use-after-free in recv_work.

Leer descripción completaMostrar menos

This patch moves nbd_start_device() after the backend file creation.

Detalles técnicos trazas, registros y código del informe original

CPU: 2 UID: 0 PID: 67 Comm: kworker/u33:0 Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: nbd6-recv recv_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
 recv_work+0x694/0xa80 drivers/block/nbd.c:1022
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.16%
Percentil entre todas las CVEs puntuadas: 5
Fecha de la puntuación: 5/10/2026

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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation75 %
Impacto principalT1059 Command and Scripting Interpreterexecution60 %

Acceso local (AV:L) sin interacción del usuario permite escalada de privilegios mediante use-after-free en nbd_genl_connect(). La ejecución de código en contexto de kernel es el impacto resultante.

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

Execution Prevention Threat Intelligence Program Restrict Web-Based Content Privileged Account Management Limit Software Installation Behavior Prevention on Endpoint

Tecnologías afectadas (2)

Debian — Debian Linux Linux — Linux Kernel

CWE

CWE-416

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2025-38443",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "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": "6497ef8df568afbf5f3e38825a4590ff41611a54",
              "lessThan": "cb121c47f364b51776c4db904a6a5a90ab0a7ec5",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6497ef8df568afbf5f3e38825a4590ff41611a54",
              "lessThan": "91fa560c73a8126868848ed6cd70607cbf8d87e2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6497ef8df568afbf5f3e38825a4590ff41611a54",
              "lessThan": "d46186eb7bbd9a11c145120f2d77effa8d4d44c2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6497ef8df568afbf5f3e38825a4590ff41611a54",
              "lessThan": "8586552df591e0a367eff44af0c586213eeecc3f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6497ef8df568afbf5f3e38825a4590ff41611a54",
              "lessThan": "002aca89753f666d878ca0eb8584c372684ac4ba",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6497ef8df568afbf5f3e38825a4590ff41611a54",
              "lessThan": "aa9552438ebf015fc5f9f890dbfe39f0c53cf37e",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/block/nbd.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.14"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.14",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.15.189",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.146",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.99",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.39",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.15.7",
              "versionType": "semver",
              "lessThanOrEqual": "6.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.16",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/block/nbd.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-07-25T16:15:29.737",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/002aca89753f666d878ca0eb8584c372684ac4ba",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8586552df591e0a367eff44af0c586213eeecc3f",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/91fa560c73a8126868848ed6cd70607cbf8d87e2",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/aa9552438ebf015fc5f9f890dbfe39f0c53cf37e",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cb121c47f364b51776c4db904a6a5a90ab0a7ec5",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d46186eb7bbd9a11c145120f2d77effa8d4d44c2",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: fix uaf in nbd_genl_connect() error path\n\nThere is a use-after-free issue in nbd:\n\nblock nbd6: Receive control failed (result -104)\nblock nbd6: shutting down sockets\n==================================================================\nBUG: KASAN: slab-use-after-free in recv_work+0x694/0xa80 drivers/block/nbd.c:1022\nWrite of size 4 at addr ffff8880295de478 by task kworker/u33:0/67\n\nCPU: 2 UID: 0 PID: 67 Comm: kworker/u33:0 Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 PREEMPT(full)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014\nWorkqueue: nbd6-recv recv_work\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:408 [inline]\n print_report+0xc3/0x670 mm/kasan/report.c:521\n kasan_report+0xe0/0x110 mm/kasan/report.c:634\n check_region_inline mm/kasan/generic.c:183 [inline]\n kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189\n instrument_atomic_read_write include/linux/instrumented.h:96 [inline]\n atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]\n recv_work+0x694/0xa80 drivers/block/nbd.c:1022\n process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238\n process_scheduled_works kernel/workqueue.c:3319 [inline]\n worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400\n kthread+0x3c2/0x780 kernel/kthread.c:464\n ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n </TASK>\n\nnbd_genl_connect() does not properly stop the device on certain\nerror paths after nbd_start_device() has been called. This causes\nthe error path to put nbd->config while recv_work continue to use\nthe config after putting it, leading to use-after-free in recv_work.\n\nThis patch moves nbd_start_device() after the backend file creation."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nbd: corrección de uaf en la ruta de error nbd_genl_connect() Hay un problema de use-after-free en nbd: bloque nbd6: Error en el control de recepción (resultado -104) bloque nbd6: apagado de sockets ================================================================== BUG: KASAN: slab-use-after-free in recv_work+0x694/0xa80 drivers/block/nbd.c:1022 Write of size 4 at addr ffff8880295de478 by task kworker/u33:0/67 CPU: 2 UID: 0 PID: 67 Comm: kworker/u33:0 Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: nbd6-recv recv_work Call Trace:  __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline] recv_work+0x694/0xa80 drivers/block/nbd.c:1022 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245  nbd_genl_connect() no detiene correctamente el dispositivo en ciertas rutas de error después de llamar a nbd_start_device(). Esto provoca que la ruta de error coloque nbd-&gt;config mientras que recv_work sigue usando la configuración después de colocarla, lo que provoca un error de use-after-free en recv_work. Esta corrección mueve nbd_start_device() después de la creación del archivo de backend."
    }
  ],
  "lastModified": "2026-06-17T09:16:52.000",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "519B13AF-5C4A-4797-A9CC-9418CFE1D9FF",
              "versionEndExcluding": "5.15.189",
              "versionStartIncluding": "5.14"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D8DA1166-5C95-475E-BF65-1DF621968E96",
              "versionEndExcluding": "6.1.146",
              "versionStartIncluding": "5.16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B369699C-E0E6-42A4-BDEE-8E676ECEF6AA",
              "versionEndExcluding": "6.6.99",
              "versionStartIncluding": "6.2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "18D57670-11F8-4B5A-AD56-EA32DD0F44E1",
              "versionEndExcluding": "6.12.39",
              "versionStartIncluding": "6.7"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F9C46937-5FA9-4335-AD7B-E7FC29453CE1",
              "versionEndExcluding": "6.15.7",
              "versionStartIncluding": "6.13"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6D4894DB-CCFE-4602-B1BF-3960B2E19A01"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "09709862-E348-4378-8632-5A7813EDDC86"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "415BF58A-8197-43F5-B3D7-D1D63057A26E"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A0517869-312D-4429-80C2-561086E1421C"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc5:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "85421F4E-C863-4ABF-B4B4-E887CC2F7F92"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}