{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-89938",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-89938"
  ],
  "published": "2026-09-16T10:32:03Z",
  "summary": "iio: chemical: atlas-sensor: use iio_trigger_poll_nested() to fix remove UAF",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\niio: chemical: atlas-sensor: use iio_trigger_poll_nested() to fix remove UAF\n\nThe atlas driver requests its hardware data-ready IRQ with\ndevm_request_threaded_irq(); its threaded handler queues an irq_work,\natlas_work_handler(), that calls iio_trigger_poll(data->trig).\n\nThe IRQ is devm-managed, so free_irq() runs from the devres unwind after\natlas_remove() returns without flushing that irq_work.  Once a buffer is\nenabled, conversion-complete IRQs keep firing and queueing it; a pending\nirq_work can therefore run after the unwind has freed atlas_data/indio_dev\nand the trigger, when atlas_work_handler() derives the atlas_data pointer\nvia container_of() and dereferences data->trig, a use-after-free.\n\nCall iio_trigger_poll_nested() directly from the threaded handler instead\nof bouncing through irq_work.  free_irq() then drains the threaded handler,\nclosing the window; other iio drivers with a threaded data-ready IRQ do the\nsame (e.g. bmi270).\n\nThis issue was found by an in-house static analysis tool.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-89938"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f64b437641b5a70c18bb0fd38da2b69d8926c871"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/91e12b0fbd7047d02bf4ef4dbc491b9ef0159250"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2071624c3d0f497ca91da78858e6f30d7112fea6"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/30b0d44c978bbc857bd68b71dab371805653de70"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/be61c8c6252671ecf1fee0ad90f87669e0be1e20"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-16T14:40:32Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The use-after-free is reached from local IIO sysfs/chardev buffer enable on the Atlas I2C chemical sensor plus driver teardown (sysfs unbind, rmmod, or parent adapter removal). There is no network, Bluetooth, or remote-protocol path into atlas_interrupt_handler or atlas_work_handler.\nAC:L - With the IIO buffer enabled, conversion-complete IRQs keep queueing irq_work every 450-650ms. atlas_remove() never calls irq_work_sync(), so pending work runs after the synchronous devres unwind frees atlas_data. The attacker controls buffer enable and bind/unbind retries; on PREEMPT_RT or CPUs without an irq_work IPI the window is milliseconds.\nPR:L - IIO buffer/enable is mode 0644 with no capability check, and on industrial/IoT water-quality systems that ship Atlas OEM SM sensors those nodes are commonly group-accessible to monitoring services. Per driver-removal UAF scoring, an unprivileged local user can drive the IRQ/irq_work side while teardown proceeds; init-namespace root is not required.\nUI:N - The attacker enables the IIO buffer themselves and coordinates driver unbind or module teardown; no separate victim action such as plugging hardware or mounting a filesystem is required.\nS:U - The use-after-free corrupts kernel heap objects (atlas_data and the IIO trigger) in the host kernel's own security authority. This is a standard local kernel privilege-escalation path, not a VM, IOMMU, or sandbox boundary crossing.\nC:H - atlas_work_handler() recovers freed atlas_data via container_of() and dereferences data->trig. A use-after-free of that sprayable driver-private object yields an arbitrary kernel read primitive, including via iio_trigger_poll() walking attacker-controlled trigger state.\nI:H - After spraying the freed atlas_data, data->trig is attacker-controlled, so iio_trigger_poll() performs atomic updates and generic_handle_irq() on attacker-chosen IRQ numbers. That is an arbitrary kernel write and control-flow hijack primitive, consistent with use-after-free scoring.\nA:H - The pending irq_work running against freed atlas_data and the IIO trigger causes a kernel oops or panic (KASAN use-after-free or a wild dereference of data->trig), so availability impact is high even without a full exploit."
    }
  }
}