CVE-2026-89489 (GCVE-0-2026-89489)
Vulnerability from cvelistv5
Published
2026-09-11 19:43
Modified
2026-10-19 08:47
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style]
References
Impacted products
Vendor Product Version
Linux Linux Version: 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a
Version: 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a
Version: 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a
Version: 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a
Version: 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a
Version: 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a
Version: 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a
Version: 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/openrisc/kernel/entry.S"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bf310718c6fa6adeee06d207a55489546d860e2c",
              "status": "affected",
              "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a",
              "versionType": "git"
            },
            {
              "lessThan": "497cba0b02e5555d99fe9ee1dc478af743ab7f7a",
              "status": "affected",
              "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a",
              "versionType": "git"
            },
            {
              "lessThan": "1f2e92e499d863f81df1732af59b4a3559969193",
              "status": "affected",
              "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a",
              "versionType": "git"
            },
            {
              "lessThan": "574ae2ac2b314aa33498cd2c28add106cbe644f2",
              "status": "affected",
              "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a",
              "versionType": "git"
            },
            {
              "lessThan": "a520e8cac54fb403f3800125b606f55fcad42cb9",
              "status": "affected",
              "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a",
              "versionType": "git"
            },
            {
              "lessThan": "d64a75369cd0f2ee79afcc9d9ca34a3890989379",
              "status": "affected",
              "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a",
              "versionType": "git"
            },
            {
              "lessThan": "b53435c079c78f89f70a62dd5a322cca4e292b34",
              "status": "affected",
              "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a",
              "versionType": "git"
            },
            {
              "lessThan": "78004e9a87f240df03e2f73120d291763c32e0a7",
              "status": "affected",
              "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/openrisc/kernel/entry.S"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.1"
            },
            {
              "lessThan": "3.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.270",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.109",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.270",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.221",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.188",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.157",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.109",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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]"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "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."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:47:40.968Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/bf310718c6fa6adeee06d207a55489546d860e2c"
        },
        {
          "url": "https://git.kernel.org/stable/c/497cba0b02e5555d99fe9ee1dc478af743ab7f7a"
        },
        {
          "url": "https://git.kernel.org/stable/c/1f2e92e499d863f81df1732af59b4a3559969193"
        },
        {
          "url": "https://git.kernel.org/stable/c/574ae2ac2b314aa33498cd2c28add106cbe644f2"
        },
        {
          "url": "https://git.kernel.org/stable/c/a520e8cac54fb403f3800125b606f55fcad42cb9"
        },
        {
          "url": "https://git.kernel.org/stable/c/d64a75369cd0f2ee79afcc9d9ca34a3890989379"
        },
        {
          "url": "https://git.kernel.org/stable/c/b53435c079c78f89f70a62dd5a322cca4e292b34"
        },
        {
          "url": "https://git.kernel.org/stable/c/78004e9a87f240df03e2f73120d291763c32e0a7"
        }
      ],
      "title": "openrisc: fix arbitrary kernel memory access via or1k_atomic syscall",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89489",
    "datePublished": "2026-09-11T19:43:42.164Z",
    "dateReserved": "2026-09-11T19:38:34.713Z",
    "dateUpdated": "2026-10-19T08:47:40.968Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.