CVE-2026-89539 (GCVE-0-2026-89539)
Vulnerability from cvelistv5
Published
2026-09-11 19:44
Modified
2026-10-21 12:47
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: SUNRPC: reject duplicate CREDS_VALUE options gssx_dec_option_array() walks the wire-supplied option array and, for every entry whose name matches CREDS_VALUE, calls gssx_dec_linux_creds() on the same struct svc_cred. That helper unconditionally installs a fresh groups_alloc() result into creds->cr_group_info without releasing whatever pointer was already there: for (i = 0; i < count; i++) { ... decode name ... if (length == sizeof(CREDS_VALUE) && memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) { err = gssx_dec_linux_creds(xdr, creds); ... } } A reply that carries two CREDS_VALUE entries therefore overwrites cr_group_info on the second iteration and orphans the group_info allocated by the first call. The earlier free_creds path only releases the last cr_group_info via free_svc_cred(), so the first allocation's refcount stays at one and its kvmalloc-backed storage is leaked. No in-tree caller of gssp_accept_sec_context_upcall() expects more than one CREDS_VALUE per reply. Fix by tracking whether a CREDS_VALUE option has already been decoded and returning -EINVAL on any subsequent match, so the free_creds path releases the single group_info that was installed.
References
Impacted products
Vendor Product Version
Linux Linux Version: 1d658336b05f8697d6445834f8867f8ad5e4f735
Version: 1d658336b05f8697d6445834f8867f8ad5e4f735
Version: 1d658336b05f8697d6445834f8867f8ad5e4f735
Version: 1d658336b05f8697d6445834f8867f8ad5e4f735
Version: 1d658336b05f8697d6445834f8867f8ad5e4f735
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/auth_gss/gss_rpc_xdr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4b5ebb4f91a6152a0f7b1253f701197e5710d4da",
              "status": "affected",
              "version": "1d658336b05f8697d6445834f8867f8ad5e4f735",
              "versionType": "git"
            },
            {
              "lessThan": "f615b884310bf82d0014e3b5a92eb9aa88146685",
              "status": "affected",
              "version": "1d658336b05f8697d6445834f8867f8ad5e4f735",
              "versionType": "git"
            },
            {
              "lessThan": "7a1d0501cbb962beba23377035d667bf3c1726ee",
              "status": "affected",
              "version": "1d658336b05f8697d6445834f8867f8ad5e4f735",
              "versionType": "git"
            },
            {
              "lessThan": "9d94f046b23de0f77849ea69133063c949297e30",
              "status": "affected",
              "version": "1d658336b05f8697d6445834f8867f8ad5e4f735",
              "versionType": "git"
            },
            {
              "lessThan": "2e4ce62385c1b8a887c5370af058ac7b52a8eaf9",
              "status": "affected",
              "version": "1d658336b05f8697d6445834f8867f8ad5e4f735",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/auth_gss/gss_rpc_xdr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.10"
            },
            {
              "lessThan": "3.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "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": "6.6.160",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.109",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: reject duplicate CREDS_VALUE options\n\ngssx_dec_option_array() walks the wire-supplied option array and, for\nevery entry whose name matches CREDS_VALUE, calls\ngssx_dec_linux_creds() on the same struct svc_cred. That helper\nunconditionally installs a fresh groups_alloc() result into\ncreds-\u003ecr_group_info without releasing whatever pointer was already\nthere:\n\n    for (i = 0; i \u003c count; i++) {\n        ... decode name ...\n        if (length == sizeof(CREDS_VALUE) \u0026\u0026\n            memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) {\n            err = gssx_dec_linux_creds(xdr, creds);\n            ...\n        }\n    }\n\nA reply that carries two CREDS_VALUE entries therefore overwrites\ncr_group_info on the second iteration and orphans the group_info\nallocated by the first call. The earlier free_creds path only\nreleases the last cr_group_info via free_svc_cred(), so the first\nallocation\u0027s refcount stays at one and its kvmalloc-backed storage\nis leaked. No in-tree caller of gssp_accept_sec_context_upcall()\nexpects more than one CREDS_VALUE per reply.\n\nFix by tracking whether a CREDS_VALUE option has already been\ndecoded and returning -EINVAL on any subsequent match, so the\nfree_creds path releases the single group_info that was installed."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T12:47:46.957Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4b5ebb4f91a6152a0f7b1253f701197e5710d4da"
        },
        {
          "url": "https://git.kernel.org/stable/c/f615b884310bf82d0014e3b5a92eb9aa88146685"
        },
        {
          "url": "https://git.kernel.org/stable/c/7a1d0501cbb962beba23377035d667bf3c1726ee"
        },
        {
          "url": "https://git.kernel.org/stable/c/9d94f046b23de0f77849ea69133063c949297e30"
        },
        {
          "url": "https://git.kernel.org/stable/c/2e4ce62385c1b8a887c5370af058ac7b52a8eaf9"
        }
      ],
      "title": "SUNRPC: reject duplicate CREDS_VALUE options",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89539",
    "datePublished": "2026-09-11T19:44:16.699Z",
    "dateReserved": "2026-09-11T19:38:34.721Z",
    "dateUpdated": "2026-10-21T12:47:46.957Z",
    "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.