{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-89489",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-89489"
  ],
  "published": "2026-09-11T19:47:07Z",
  "summary": "openrisc: fix arbitrary kernel memory access via or1k_atomic syscall",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nopenrisc: fix arbitrary kernel memory access via or1k_atomic syscall\n\nsys_or1k_atomic() (syscall 244 in the \"or1k\" ABI) takes two user\npointers, v1 and v2, and swaps the words they point to in hand-written\nassembly.\n\n    l.lwz   r29,0(r4)\n    l.lwz   r27,0(r5)\n    l.sw    0(r4),r27\n    l.sw    0(r5),r29\n\nThe pointers are not checked with access_ok(). The four memory\naccesses also have no exception table entries.\n\nA caller passes a kernel address as either pointer, and the syscall\nreads from and writes to it directly.\n\nThis gives an unprivileged process a kernel read/write primitive. It\noverwrites kernel data such as the sys_call_table, gaining code\nexecution in kernel context.\n\nCheck both pointers before entering the critical section. Add fixups\nfor the four memory accesses so faults on valid but unmapped user\naddresses return -EFAULT.\n\n[shorne@gmail.com: fix comment style]",
  "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-2026-89489"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bf310718c6fa6adeee06d207a55489546d860e2c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/497cba0b02e5555d99fe9ee1dc478af743ab7f7a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1f2e92e499d863f81df1732af59b4a3559969193"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/574ae2ac2b314aa33498cd2c28add106cbe644f2"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a520e8cac54fb403f3800125b606f55fcad42cb9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d64a75369cd0f2ee79afcc9d9ca34a3890989379"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b53435c079c78f89f70a62dd5a322cca4e292b34"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/78004e9a87f240df03e2f73120d291763c32e0a7"
    }
  ],
  "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 - sys_or1k_atomic (syscall 244) is reached only via a local OpenRISC syscall into _sys_call_handler and sys_call_table; there is no network, adjacent-wireless, or physical-device path to the unchecked loads/stores in arch/openrisc/kernel/entry.S.\nAC:L - The attacker fully controls both pointer arguments and the swap is deterministic with no race or KASLR (OpenRISC has none); a published unprivileged PoC on qemu-system-or1k overwrote sys_call_table[174] and obtained uid=0 on every run.\nPR:L - Any unprivileged local process can invoke syscall 244; the handler performs no capable()/ns_capable() check, authentication, or init-namespace root gate before dereferencing the caller-supplied pointers.\nUI:N - The attacking process issues or1k_atomic itself with crafted kernel addresses; no other user must mount a filesystem, open a device, or otherwise interact.\nS:U - This is a standard host-kernel privilege escalation (arbitrary kernel R/W and commit_creds via a hijacked syscall); it does not cross a VM guest/host, IOMMU, or other security-authority boundary.\nC:H - The syscall atomically swaps two 32-bit words at attacker-chosen addresses with no access_ok(), so pairing a kernel pointer with a userspace buffer yields an arbitrary kernel-memory read primitive of any mapped word.\nI:H - The same swap is an arbitrary kernel write; the fix commit documents overwriting sys_call_table to run commit_creds(init_cred) and gain root, i.e. control-flow hijacking and full integrity compromise.\nA:H - Writes to unmapped or critical kernel addresses oops or panic because the original accesses had no exception-table fixups, and corrupting kernel text, data, or the syscall table can hang or crash the machine even without a full root exploit."
    }
  }
}