FKIE_CVE-2026-74630

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-10-14 13:10
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent in6_dev_get() from resurrecting inet6_dev in6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally increments its refcount. Device teardown can clear the pointer and drop the last reference between these operations. The increment then resurrects an object whose RCU free has already been queued, so callers can use it after it is freed. Use refcount_inc_not_zero() and return NULL when the object has already reached zero. RCU keeps the memory accessible through the attempted reference acquisition, and a successful increment pins the object for the caller. An independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3) kernel reproduced the invalid reference acquisition as UID 1000: refcount_t: addition on 0; use-after-free. ip6_mc_source+0xef4/0x17e0 It was followed by the corresponding reference underflow in ip6_mc_source(). The supplied trace from the same unpatched revision additionally shows the access after the RCU read-side section ends: BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0 Write of size 8 at addr ffff888015b50240 by task poc/1219 Bug found and triaged by OpenAI Security Research and validated by Trail of Bits.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/addrconf.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "785d908f8d21c8bc78b6fb2c2932ab662bf6918a",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "145812b678de9f3b59780173be3c0d22ed60dd93",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "cc5bd568f9b7683e60841b6fd02c10d64535bd6e",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "1c206d461c680c3151daa3c89fc26eaf5bf98a7f",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "680fbd7942185448eadb990a3d10a53eb946b702",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "14e812ab41df0cac033479da835ec9a5de633404",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "0e243671bc7b8eaf00f83dd2f4367436dc0cff98",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/addrconf.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.19"
            },
            {
              "lessThan": "2.6.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\nipv6: prevent in6_dev_get() from resurrecting inet6_dev\n\nin6_dev_get() reads dev-\u003eip6_ptr under RCU and then unconditionally\nincrements its refcount. Device teardown can clear the pointer and drop\nthe last reference between these operations. The increment then\nresurrects an object whose RCU free has already been queued, so callers\ncan use it after it is freed.\n\nUse refcount_inc_not_zero() and return NULL when the object has already\nreached zero. RCU keeps the memory accessible through the attempted\nreference acquisition, and a successful increment pins the object for\nthe caller.\n\nAn independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3)\nkernel reproduced the invalid reference acquisition as UID 1000:\n\n  refcount_t: addition on 0; use-after-free.\n  ip6_mc_source+0xef4/0x17e0\n\nIt was followed by the corresponding reference underflow in\nip6_mc_source(). The supplied trace from the same unpatched revision\nadditionally shows the access after the RCU read-side section ends:\n\n  BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0\n  Write of size 8 at addr ffff888015b50240 by task poc/1219\n\nBug found and triaged by OpenAI Security Research and\nvalidated by Trail of Bits."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nipv6: evitar que in6_dev_get() resucite inet6_dev\n\nin6_dev_get() lee dev -\u003e ip6_ptr bajo RCU y luego incrementa incondicionalmente su refcount. La desinstalaci\u00f3n del dispositivo puede borrar el puntero y eliminar la \u00faltima referencia entre estas operaciones. El incremento entonces resucita un objeto cuya liberaci\u00f3n RCU ya ha sido encolada, por lo que los llamadores pueden usarlo despu\u00e9s de que sea liberado.\n\nUse refcount_inc_not_zero() y devuelva NULL cuando el objeto ya haya llegado a cero. RCU mantiene la memoria accesible a trav\u00e9s de la adquisici\u00f3n de referencia intentada, y un incremento exitoso fija el objeto para el llamador.\n\nUna ejecuci\u00f3n independiente en el kernel exacto sin parchear 6f5156d7a31a (v7.2-rc3) reprodujo la adquisici\u00f3n de referencia inv\u00e1lida como UID 1000:\n\n  refcount_t: adici\u00f3n en 0; uso despu\u00e9s de liberaci\u00f3n.\n  ip6_mc_source+0xef4/0x17e0\n\nFue seguido por el subdesbordamiento de referencia correspondiente en ip6_mc_source(). La traza proporcionada de la misma revisi\u00f3n sin parchear muestra adicionalmente el acceso despu\u00e9s de que termina la secci\u00f3n de lectura de RCU:\n\n  BUG: KASAN: uso despu\u00e9s de liberaci\u00f3n de slab en mutex_lock+0x76/0xe0\n  Escritura de tama\u00f1o 8 en la direcci\u00f3n ffff888015b50240 por la tarea PoC/1219\n\nError encontrado y clasificado por OpenAI Security Research y validado por Trail of Bits."
    }
  ],
  "id": "CVE-2026-74630",
  "lastModified": "2026-10-14T13:10:00.187",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-22T16:16:35.943",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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