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CVE-2026-74677

Estado: RecibidaSin puntuar—

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

net: usb: ipheth: fix carrier_work UAF on disconnect

ipheth_sndbulk_callback() re-arms the carrier-check work on any non-zero URB status:

Nothing ties that to the interface being up, so the work can be armed again after ipheth_close() has already drained it, and stay armed until the netdev whose private area embeds it is freed.

On unplug with a TX URB in flight, ipheth_disconnect() drains the work through unregister_netdev() -> ipheth_close() -> cancel_delayed_work_sync() and only then calls ipheth_kill_urbs(). usb_kill_urb() completes the in-flight TX URB with -ENOENT, so ipheth_sndbulk_callback() runs after the drain and re-arms carrier_work.

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The same completion also re-arms the work if the interface is only brought down while a TX URB is in flight, and ipheth_carrier_check_work() then keeps re-queueing itself once a second. unregister_netdev() does not call ipheth_close() for an already-down interface, so nothing drains it on the later unplug either.

In both cases free_netdev() frees the netdev while carrier_work is still pending, and ipheth_carrier_check_work() dereferences freed memory.

Tie the work to the interface state instead of chasing the completion: disable it in ipheth_close() and enable it in ipheth_open(), so a schedule_delayed_work() from the URB completion is a no-op whenever the interface is not up. disable_delayed_work_sync() also waits for a running instance, so it fully replaces the cancel_delayed_work_sync() it takes the place of. The work starts out disabled in ipheth_probe() so the enable/disable counts balance from the first open.

Reproduced under KASAN on linux-next (next-20260731) with dummy_hcd and raw-gadget standing in for the device, driving the second path above (the interface is already down, so unregister_netdev() does not call ipheth_close()): 15 of 15 unpatched boots report a slab-use-after-free in __run_timers(), freed by ipheth_disconnect() and re-armed from ipheth_sndbulk_callback() via queue_delayed_work_on(). The same trigger on a kernel differing only by this patch reports 0 of 15, and the carrier check still functions across open/close cycles.

The reproducer needs an attached USB device that stops draining bulk OUT, plus a link down and unplug, driven as root. It is not a privilege boundary crossing and no exploit primitive was developed.

Found by 0sec (https://0sec.ai).

Detalles técnicos trazas, registros y código del informe original
	else
		schedule_delayed_work(&dev->carrier_work, 0);

CVSS

NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).

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)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-74677",
  "cveTags": [],
  "metrics": {},
  "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": "bb1b40c7cb863f0800a6410c7dcb86cf3f28d3b1",
              "lessThan": "d07133fe1befae9a1e4c4c5e46ef0b73d2992020",
              "versionType": "git"
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            {
              "status": "affected",
              "version": "bb1b40c7cb863f0800a6410c7dcb86cf3f28d3b1",
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              "versionType": "git"
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            {
              "status": "affected",
              "version": "bb1b40c7cb863f0800a6410c7dcb86cf3f28d3b1",
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              "status": "affected",
              "version": "ea7d6be58c2e6c1f426b48994bb22b2393c90963",
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            {
              "status": "affected",
              "version": "f5bca75dc46701f4c0d1dcbaae401233ae7ff06b",
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            {
              "status": "affected",
              "version": "4.4.180",
              "lessThan": "4.5",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "4.9.173",
              "lessThan": "4.10",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "4.14.116",
              "lessThan": "4.15",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "drivers/net/usb/ipheth.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.15"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "4.15",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/net/usb/ipheth.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-22T16:16:41.847",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/2c7496124e94c7f9c3daa5c5b1fb563ca9d62c45",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/48303f3ae0fa6e102f3fc7dbf1688cc179131962",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d07133fe1befae9a1e4c4c5e46ef0b73d2992020",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/fde39b8a521780391fb4e5bda2c0aa4928947f12",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: usb: ipheth: fix carrier_work UAF on disconnect\n\nipheth_sndbulk_callback() re-arms the carrier-check work on any\nnon-zero URB status:\n\n\telse\n\t\tschedule_delayed_work(&dev->carrier_work, 0);\n\nNothing ties that to the interface being up, so the work can be armed\nagain after ipheth_close() has already drained it, and stay armed\nuntil the netdev whose private area embeds it is freed.\n\nOn unplug with a TX URB in flight, ipheth_disconnect() drains the work\nthrough unregister_netdev() -> ipheth_close() ->\ncancel_delayed_work_sync() and only then calls ipheth_kill_urbs().\nusb_kill_urb() completes the in-flight TX URB with -ENOENT, so\nipheth_sndbulk_callback() runs after the drain and re-arms\ncarrier_work.\n\nThe same completion also re-arms the work if the interface is only\nbrought down while a TX URB is in flight, and\nipheth_carrier_check_work() then keeps re-queueing itself once a\nsecond. unregister_netdev() does not call ipheth_close() for an\nalready-down interface, so nothing drains it on the later unplug\neither.\n\nIn both cases free_netdev() frees the netdev while carrier_work is\nstill pending, and ipheth_carrier_check_work() dereferences freed\nmemory.\n\nTie the work to the interface state instead of chasing the completion:\ndisable it in ipheth_close() and enable it in ipheth_open(), so a\nschedule_delayed_work() from the URB completion is a no-op whenever\nthe interface is not up. disable_delayed_work_sync() also waits for a\nrunning instance, so it fully replaces the cancel_delayed_work_sync()\nit takes the place of. The work starts out disabled in ipheth_probe()\nso the enable/disable counts balance from the first open.\n\nReproduced under KASAN on linux-next (next-20260731) with dummy_hcd and\nraw-gadget standing in for the device, driving the second path above (the\ninterface is already down, so unregister_netdev() does not call\nipheth_close()): 15 of 15 unpatched boots report a slab-use-after-free in\n__run_timers(), freed by ipheth_disconnect() and re-armed from\nipheth_sndbulk_callback() via queue_delayed_work_on(). The\nsame trigger on a kernel differing only by this patch reports 0 of 15,\nand the carrier check still functions across open/close cycles.\n\nThe reproducer needs an attached USB device that stops draining bulk OUT,\nplus a link down and unplug, driven as root. It is not a privilege\nboundary crossing and no exploit primitive was developed.\n\nFound by 0sec (https://0sec.ai)."
    }
  ],
  "lastModified": "2026-08-22T16:16:41.847",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}