{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "260f3ea141382386e97611e7c2029bc013088ab1"
            },
            {
              "fixed": "31fa0a8a3c337ed2d200166d6926ab23c14f8b2e"
            },
            {
              "fixed": "e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9"
            },
            {
              "fixed": "69632952aca04caa71e49953b6949fc04e788e67"
            },
            {
              "fixed": "7db2511fc601ca3a6e3fb1bdce02261c3c3167c3"
            },
            {
              "fixed": "dd6f4ef6f8a37412909ad787c837332fb070159c"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.0.0"
            },
            {
              "fixed": "6.6.157"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.110"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.51"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89955.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio-ap: Fix NULL deref in status_show() during queue probe\n\nWhen vfio_ap_mdev_probe_queue() creates the sysfs attribute group,\nthe queue's driver data has not yet been set. A concurrent read of\nthe 'status' attribute can therefore call dev_get_drvdata() and\nget NULL, which is then passed directly to\nvfio_ap_mdev_for_queue() where q-\u003eapqn is unconditionally\ndereferenced, causing a NULL pointer dereference.\n\nFix this by acquiring the update locks before calling\nsysfs_create_group(). The status_show() function acquires\nguests_lock before reading the driver data, so any concurrent\nread will block until after dev_set_drvdata() has been called\nand the update locks are released.\n\nAs a bonus, the APQN no longer needs to be read from the queue\nstruct after allocation — it can be read directly from apdev\nbefore allocation and stored in a local variable, which is then\nassigned to q-\u003eapqn once the allocation succeeds.",
  "id": "CVE-2026-89955",
  "modified": "2026-09-18T03:31:04.906552629Z",
  "published": "2026-09-16T10:32:39.064Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/31fa0a8a3c337ed2d200166d6926ab23c14f8b2e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/69632952aca04caa71e49953b6949fc04e788e67"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7db2511fc601ca3a6e3fb1bdce02261c3c3167c3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dd6f4ef6f8a37412909ad787c837332fb070159c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89955.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89955"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "s390/vfio-ap: Fix NULL deref in status_show() during queue probe"
}