{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-89893",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-89893"
  ],
  "published": "2026-09-16T10:32:03Z",
  "summary": "media: cx23885: cancel NetUP CI work before teardown",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cx23885: cancel NetUP CI work before teardown\n\nnetup_ci_exit() frees a netup_ci_state while its work item,\nnetup_read_ci_status(), may still be pending or running on the system\nworkqueue. The worker obtains the state with container_of() and\ndereferences it, so it must not outlive the state.\n\nnetup_ci_init() queues the initial status read, and CI GPIO interrupts\nsubsequently queue the same work from netup_ci_slot_status(). During\nremove, cx23885_finidev() calls free_irq() before the CI device is\nunregistered. free_irq() prevents further IRQ handlers from running,\nbut does not drain work queued previously, so the worker can run after\nnetup_ci_exit() frees the state.\n\nCall cancel_work_sync() before dvb_ca_en50221_release() and kfree().\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": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-89893"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/aaf76794b870b0f391eff339252a2e2e22f33a4a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f7ff5adb63c1b277565afa54ccc0924d841b4a52"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/140ecbcbf978fbe60f83f8d4f8b1199029a5c763"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ec82b0cf7f75fd95802592dcc9560fc7f529bba4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5deec890ecfa04d21cfa9bb9a2fe5e9dc98db5c5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bf3f49273d5bf6acbdad18ff44c01ffcf7a7a146"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/99cd62b9b1c818d6d01a87be9a8e5796314150a2"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4e143d662ca94888b494b2427fc9e34494eb933a"
    }
  ],
  "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 only on local PCI teardown of the NetUP Dual DVB-S2 CI card (cx23885_finidev \u2192 cx23885_dvb_unregister \u2192 netup_ci_exit) via sysfs unbind/remove, rmmod, or local PCI hot-remove. No network, adjacent-network, or remote-peer path queues netup_read_ci_status or frees netup_ci_state.\nAC:L - netup_ci_init() unconditionally schedule_work()s the status worker, and CAM GPIO IRQs re-queue it via netup_ci_slot_status(); an attacker who then unbinds/rebinds controls both sides of the missing cancel_work_sync race. The worker's 33-byte I2C transfer widens a retryable window, so this UAF is Low complexity.\nPR:L - Per CNA driver-removal UAF precedent on this same NetUP PCIe DVB family (CVE-2023-53219), an unprivileged local video-group/uaccess user on broadcast, HTPC, or set-top systems can spray the freed netup_ci_state while teardown proceeds. Init-namespace root is not required for the UAF itself.\nUI:N - The attacker queues the CI work (driver bind or CAM GPIO) and initiates PCI unbind, rmmod, or hot-remove themselves. No separate victim action such as mounting a filesystem or opening attacker-supplied content is required.\nS:U - The use-after-free corrupts the host kernel netup_ci_state heap object and dvb_ca_en50221 private state within the same security authority. It is not a VM escape, IOMMU/DMA isolation bypass, or sandbox breakout.\nC:H - After kfree(state), netup_read_ci_status recovers the object via container_of() and reads state->ca, i2c_adap, and status from freed memory. Spraying the slab turns this kernel heap UAF into an arbitrary read, which per UAF guidance is Confidentiality High.\nI:H - The dangling worker writes state->status/next_status_checked_time and calls dvb_ca_en50221_frda_irq(), which loads ca->pub->read_cam_control from the freed object, a heap-spray function-pointer hijack. UAF memory corruption is scored Integrity High.\nA:H - Use-after-free of netup_ci_state from workqueue context after kfree, or a NULL deref of ca->private if the worker interleaves dvb_ca_en50221_release, oopses or panics the kernel even when not fully exploited, so availability impact is High."
    }
  }
}