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CVE-2025-38621

Estado: ModificadaMedia (5.5)—

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

md: make rdev_addable usable for rcu mode

Our testcase trigger panic:

md_spares_need_change in md_start_sync will call rdev_addable which protected by rcu_read_lock/rcu_read_unlock. This rcu context will help protect rdev won't be released, but rdev->mddev will be set to NULL before we call synchronize_rcu in md_kick_rdev_from_array. Fix this by using READ_ONCE and check does rdev->mddev still alive.

Detalles técnicos trazas, registros y código del informe original
BUG: kernel NULL pointer dereference, address: 00000000000000e0
...
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 2 UID: 0 PID: 85 Comm: kworker/2:1 Not tainted 6.16.0+ #94
PREEMPT(none)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
Workqueue: md_misc md_start_sync
RIP: 0010:rdev_addable+0x4d/0xf0
...
Call Trace:
 <TASK>
 md_start_sync+0x329/0x480
 process_one_work+0x226/0x6d0
 worker_thread+0x19e/0x340
 kthread+0x10f/0x250
 ret_from_fork+0x14d/0x180
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Modules linked in: raid10
CR2: 00000000000000e0
---[ end trace 0000000000000000 ]---
RIP: 0010:rdev_addable+0x4d/0xf0

CVSS

Probabilidad de explotación (EPSS)

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).

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2025-38621",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "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": "bc08041b32abe6c9824f78735bac22018eabfc06",
              "lessThan": "d713e105a6137d3f54f09d4d9e2273482057ca17",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "bc08041b32abe6c9824f78735bac22018eabfc06",
              "lessThan": "b5fbe940862339cdcc34dea7a057ad18d18fa137",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "bc08041b32abe6c9824f78735bac22018eabfc06",
              "lessThan": "13017b427118f4311471ee47df74872372ca8482",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/md/md.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.7",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.109",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.16.1",
              "versionType": "semver",
              "lessThanOrEqual": "6.16.*"
            },
            {
              "status": "unaffected",
              "version": "6.17",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/md/md.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-08-22T16:15:35.460",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/13017b427118f4311471ee47df74872372ca8482",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b5fbe940862339cdcc34dea7a057ad18d18fa137",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d713e105a6137d3f54f09d4d9e2273482057ca17",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmd: make rdev_addable usable for rcu mode\n\nOur testcase trigger panic:\n\nBUG: kernel NULL pointer dereference, address: 00000000000000e0\n...\nOops: Oops: 0000 [#1] SMP NOPTI\nCPU: 2 UID: 0 PID: 85 Comm: kworker/2:1 Not tainted 6.16.0+ #94\nPREEMPT(none)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS\n1.16.1-2.fc37 04/01/2014\nWorkqueue: md_misc md_start_sync\nRIP: 0010:rdev_addable+0x4d/0xf0\n...\nCall Trace:\n <TASK>\n md_start_sync+0x329/0x480\n process_one_work+0x226/0x6d0\n worker_thread+0x19e/0x340\n kthread+0x10f/0x250\n ret_from_fork+0x14d/0x180\n ret_from_fork_asm+0x1a/0x30\n </TASK>\nModules linked in: raid10\nCR2: 00000000000000e0\n---[ end trace 0000000000000000 ]---\nRIP: 0010:rdev_addable+0x4d/0xf0\n\nmd_spares_need_change in md_start_sync will call rdev_addable which\nprotected by rcu_read_lock/rcu_read_unlock. This rcu context will help\nprotect rdev won't be released, but rdev->mddev will be set to NULL\nbefore we call synchronize_rcu in md_kick_rdev_from_array. Fix this by\nusing READ_ONCE and check does rdev->mddev still alive."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: md: hacer que rdev_addable sea utilizable para el modo rcu Nuestro caso de prueba activa el pánico: ERROR: desreferencia de puntero NULL del kernel, dirección: 00000000000000e0 ... Oops: Oops: 0000 [#1] SMP NOPTI CPU: 2 UID: 0 PID: 85 Comm: kworker/2:1 No contaminado 6.16.0+ #94 PREEMPT(none) Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 01/04/2014 Cola de trabajo: md_misc md_start_sync RIP: 0010:rdev_addable+0x4d/0xf0 ... Rastreo de llamadas:  Módulos vinculados en: raid10 CR2: 00000000000000e0 ---[ fin de seguimiento 000000000000000 ]--- RIP: 0010:rdev_addable+0x4d/0xf0 md_spares_need_change en md_start_sync llamará a rdev_addable que está protegido por rcu_read_lock/rcu_read_unlock. Este contexto rcu ayudará a proteger rdev, ya que no se liberará, pero rdev-&gt;mddev se establecerá en NULL antes de llamar a synchronize_rcu en md_kick_rdev_from_array. Para solucionar esto, use READ_ONCE y compruebe si rdev-&gt;mddev sigue activo."
    }
  ],
  "lastModified": "2026-09-07T16:17:27.777",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D14ECFCD-ABDE-4C5C-8550-773D587E5383",
              "versionEndExcluding": "6.16.1",
              "versionStartIncluding": "6.7"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}