FKIE_CVE-2026-90149

Vulnerability from fkie_nvd - Published: 2026-09-17 17:17 - Updated: 2026-10-30 13:20
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: NFSv4/flexfiles: fix NULL dereference for NFSv4.0 data servers flexfiles accepts NFSv4.0 data servers, but two NFSv4 code paths assume the data server client has a session. Unlike NFSv4.1+, an NFSv4.0 client has no session (clp->cl_session is NULL; it uses clp->cl_slot_tbl), so I/O to a v4.0 flexfiles DS oopses: - nfs4_init_ds_session() dereferences clp->cl_session->session_state while seeding the DS lease. It also only seeds cl_lease_time when NFS4_SESSION_INITING is set; without a session that never happens, so cl_lease_time stays 0 and nfs4_renew_state() busy-loops, requeuing every 5 seconds. Seed the lease whenever there is no session and return before touching session state. - ff_layout_async_handle_error_v4() dereferences clp->cl_session->fc_slot_table on every DS I/O error. Fall back to the v4.0 transport slot table (clp->cl_slot_tbl) when there is no session.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/163c16e01f53fc8eb8d0f3484ae6c382265ecbbd
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2b03ebbf8d5e8f6af4ecd6c65375232dd1ec32cc
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/336b6da10021c69a8f273bbacdf7432fdc89a06f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/436a214514e24103159aea455147d58b44a8a585
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5527af72b0100c94287bfec901b6313eeac567ca
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e55d7fec8a9290f73032ee34c35dd68532809633
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nfs/flexfilelayout/flexfilelayout.c",
            "fs/nfs/nfs4session.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e55d7fec8a9290f73032ee34c35dd68532809633",
              "status": "affected",
              "version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
              "versionType": "git"
            },
            {
              "lessThan": "336b6da10021c69a8f273bbacdf7432fdc89a06f",
              "status": "affected",
              "version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
              "versionType": "git"
            },
            {
              "lessThan": "5527af72b0100c94287bfec901b6313eeac567ca",
              "status": "affected",
              "version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
              "versionType": "git"
            },
            {
              "lessThan": "163c16e01f53fc8eb8d0f3484ae6c382265ecbbd",
              "status": "affected",
              "version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
              "versionType": "git"
            },
            {
              "lessThan": "436a214514e24103159aea455147d58b44a8a585",
              "status": "affected",
              "version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
              "versionType": "git"
            },
            {
              "lessThan": "2b03ebbf8d5e8f6af4ecd6c65375232dd1ec32cc",
              "status": "affected",
              "version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nfs/flexfilelayout/flexfilelayout.c",
            "fs/nfs/nfs4session.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.12"
            },
            {
              "lessThan": "4.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.191",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.114",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4/flexfiles: fix NULL dereference for NFSv4.0 data servers\n\nflexfiles accepts NFSv4.0 data servers, but two NFSv4 code paths assume\nthe data server client has a session. Unlike NFSv4.1+, an NFSv4.0 client\nhas no session (clp-\u003ecl_session is NULL; it uses clp-\u003ecl_slot_tbl), so\nI/O to a v4.0 flexfiles DS oopses:\n\n  - nfs4_init_ds_session() dereferences clp-\u003ecl_session-\u003esession_state\n    while seeding the DS lease. It also only seeds cl_lease_time when\n    NFS4_SESSION_INITING is set; without a session that never happens, so\n    cl_lease_time stays 0 and nfs4_renew_state() busy-loops, requeuing\n    every 5 seconds. Seed the lease whenever there is no session and\n    return before touching session state.\n\n  - ff_layout_async_handle_error_v4() dereferences\n    clp-\u003ecl_session-\u003efc_slot_table on every DS I/O error. Fall back to the\n    v4.0 transport slot table (clp-\u003ecl_slot_tbl) when there is no session."
    }
  ],
  "id": "CVE-2026-90149",
  "lastModified": "2026-10-30T13:20:43.453",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-17T17:17:07.830",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/163c16e01f53fc8eb8d0f3484ae6c382265ecbbd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2b03ebbf8d5e8f6af4ecd6c65375232dd1ec32cc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/336b6da10021c69a8f273bbacdf7432fdc89a06f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/436a214514e24103159aea455147d58b44a8a585"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5527af72b0100c94287bfec901b6313eeac567ca"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e55d7fec8a9290f73032ee34c35dd68532809633"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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