CVE-2026-89955

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: s390/vfio-ap: Fix NULL deref in status_show() during queue probe When vfio_ap_mdev_probe_queue() creates the sysfs attribute group, the queue's driver data has not yet been set. A concurrent read of the 'status' attribute can therefore call dev_get_drvdata() and get NULL, which is then passed directly to vfio_ap_mdev_for_queue() where q->apqn is unconditionally dereferenced, causing a NULL pointer dereference. Fix this by acquiring the update locks before calling sysfs_create_group(). The status_show() function acquires guests_lock before reading the driver data, so any concurrent read will block until after dev_set_drvdata() has been called and the update locks are released. As a bonus, the APQN no longer needs to be read from the queue struct after allocation — it can be read directly from apdev before allocation and stored in a local variable, which is then assigned to q->apqn once the allocation succeeds.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-16 11:17:05.797000

Last modified

2026-10-30 13:20:36.663000

View original CVE JSON

{
  "id": "CVE-2026-89955",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-16T11:17:05.797",
  "lastModified": "2026-10-30T13:20:36.663",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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->apqn 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->apqn once the allocation succeeds."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/s390/crypto/vfio_ap_ops.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "260f3ea141382386e97611e7c2029bc013088ab1",
              "lessThan": "10606c9af18baed75cd180b96ee695441aa15134",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "260f3ea141382386e97611e7c2029bc013088ab1",
              "lessThan": "31fa0a8a3c337ed2d200166d6926ab23c14f8b2e",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "260f3ea141382386e97611e7c2029bc013088ab1",
              "lessThan": "e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "260f3ea141382386e97611e7c2029bc013088ab1",
              "lessThan": "69632952aca04caa71e49953b6949fc04e788e67",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "260f3ea141382386e97611e7c2029bc013088ab1",
              "lessThan": "7db2511fc601ca3a6e3fb1bdce02261c3c3167c3",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "260f3ea141382386e97611e7c2029bc013088ab1",
              "lessThan": "dd6f4ef6f8a37412909ad787c837332fb070159c",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/s390/crypto/vfio_ap_ops.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.0",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.0",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.157",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.110",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.51",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.5",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/10606c9af18baed75cd180b96ee695441aa15134",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/31fa0a8a3c337ed2d200166d6926ab23c14f8b2e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/69632952aca04caa71e49953b6949fc04e788e67",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/7db2511fc601ca3a6e3fb1bdce02261c3c3167c3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/dd6f4ef6f8a37412909ad787c837332fb070159c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}