{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-89597",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-89597"
  ],
  "published": "2026-09-11T19:47:07Z",
  "summary": "fbdev: uvesafb: unregister connector callback on init failure",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: uvesafb: unregister connector callback on init failure\n\nuvesafb_init() registers the v86d connector callback before registering\nthe platform driver. If platform_driver_register() fails, the function\nreturns the error directly and leaves the connector callback registered.\n\nThe later platform-device failure path already unregisters the callback.\nAdd the same cleanup before the final return when platform-driver\nregistration fails.\n\nThis issue was identified during our ongoing static-analysis research while\nreviewing kernel code.",
  "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-2026-89597"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b149f77d04082a9da75944cdc488becb0e35258f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0352fdac3cbf11e3b323322ff8cd95e20cbf5cd7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/17518e7123f7ef01b1155064dc01f2087583908e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/9eb7b3cbe99c9c0edbff69eb155c723e30983c22"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/9f8a822b44c42502f105cf6574f4867067eecdd0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/466a8af0dee2cf745307155e26884e19a37b7e15"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/9e768ae51426af2034d479133cfd73010d641b1a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/de8db23aa7c337e606fca9faf48b3ba72968597a"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-14T12:06:03Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The leftover v86d connector callback is reached only via a local NETLINK_CONNECTOR socket: cn_rx_skb() -> cn_call_callback() invokes the registered handler. There is no remote packet, Bluetooth/WiFi, or USB path into this code.\nAC:L - Once platform_driver_register() fails, cn_add_callback() has already left uvesafb_cn_callback on the global connector list while free_module() unmaps the driver. A single NETLINK_CONNECTOR message with CN_IDX_V86D/CN_VAL_V86D_UVESAFB then calls that stale pointer with no race or other condition beyond the attacker's control.\nPR:L - Unprivileged users may create NETLINK_CONNECTOR sockets and send to kernel portid 0 without CAP_NET_ADMIN. The callback's capable(CAP_SYS_ADMIN) check never runs because the UAF occurs at the call through the freed module text, so init-namespace root is not required.\nUI:N - The attacker sends the netlink message from their own process. No separate victim action such as mounting a filesystem, opening a device node, or loading a module is required to hit the dangling callback.\nS:U - The stale function pointer and freed uvesafb module memory are kernel-side resources in the same security authority. This is local privilege escalation, not VM escape, IOMMU bypass, or another cross-boundary impact.\nC:H - The leftover cn_callback_entry still points at uvesafb_cn_callback in freed module text. That use-after-free lets an attacker reclaim the pages and obtain an arbitrary kernel read primitive.\nI:H - Calling through a function pointer that resides in freed module memory is a control-flow hijack once those pages are reallocated, giving an arbitrary write and code-execution primitive.\nA:H - Invoking the stale connector callback jumps into unmapped or reused module text and reliably oopses or panics the kernel even if the attacker does not fully exploit the UAF."
    }
  }
}