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CVE-2026-89948 (GCVE-0-2026-89948)

Vulnerability from cvelistv5 – Published: 2026-09-16 10:32 – Updated: 2026-09-16 10:32
VLAI
Title
batman-adv: bla: fix freeing of claims on meshif deletion
Summary
In the Linux kernel, the following vulnerability has been resolved: batman-adv: bla: fix freeing of claims on meshif deletion When the mesh interface is getting deleted, then batadv_bla_del_backbone_claims() (via batadv_bla_purge_backbone_gw()) could make sure that all claims gets removed. But this function is only executed when bat_priv->bla.claim_hash is not NULL. And since batadv_bla_free() is always setting it to NULL before it is (indirectly) called, it was never actually executed. But the batadv_bla_purge_claims() -> batadv_handle_unclaim() is at the moment too fragile because the BLA code is not handling the rehashing in batadv_bla_update_orig_address(). The stored backbone address doesn't have to be the one actually used for the hash bucket selection during the initial adding of the backbone. The batadv_handle_unclaim() can therefore fail to find the respective backbone for the unclaim and then stop the deletion. But the actual backbone_gw object is not needed for the unclaim because all relevant information is always provided by the caller. And the check for the existence of the backbone_gw doesn't provide any additional security check for the deletion of a claim.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 23721387c409087fd3b97e274f34d3ddc0970b74 , < 844a95a734f178d56c7acce14c5cce2cecff7e1a (git)
Affected: 23721387c409087fd3b97e274f34d3ddc0970b74 , < baeb1a28fd8e2f68193650d3664a8cd1adfd85c6 (git)
Affected: 23721387c409087fd3b97e274f34d3ddc0970b74 , < aacffa780a37e06cd5a13d33740a6e96c3a67e6c (git)
Affected: 23721387c409087fd3b97e274f34d3ddc0970b74 , < 76aedcde5a2489cc971d4d1e396e784a49565e96 (git)
Affected: 23721387c409087fd3b97e274f34d3ddc0970b74 , < f50edb69082a8ba990cc23d642089829f99afe6a (git)
Affected: 23721387c409087fd3b97e274f34d3ddc0970b74 , < 871acdf97f64cee8398f72b88b89e8b4f4816dbe (git)
Affected: 23721387c409087fd3b97e274f34d3ddc0970b74 , < 9a0c47023d3254048a1588534755d4476bcc3abc (git)
Affected: 23721387c409087fd3b97e274f34d3ddc0970b74 , < 8d128c932bced74e3b1625ba3d7c78ef122a88a7 (git)
guessed Create a notification for this product.
Linux Linux Affected: 3.5
Unaffected: 0 , < 3.5 (semver)
Unaffected: 5.10.270 , ≤ 5.10.* (semver)
Unaffected: 5.15.221 , ≤ 5.15.* (semver)
Unaffected: 6.1.188 , ≤ 6.1.* (semver)
Unaffected: 6.6.157 , ≤ 6.6.* (semver)
Unaffected: 6.12.110 , ≤ 6.12.* (semver)
Unaffected: 6.18.51 , ≤ 6.18.* (semver)
Unaffected: 7.2.5 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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          "product": "Linux",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.5"
            },
            {
              "lessThan": "3.5",
              "status": "unaffected",
              "version": "0",
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              "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"
            },
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              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.270",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
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                  "versionEndExcluding": "5.15.221",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
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              ],
              "negate": false,
              "operator": "OR"
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          ]
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: bla: fix freeing of claims on meshif deletion\n\nWhen the mesh interface is getting deleted, then\nbatadv_bla_del_backbone_claims() (via batadv_bla_purge_backbone_gw()) could\nmake sure that all claims gets removed. But this function is only executed\nwhen bat_priv-\u003ebla.claim_hash is not NULL. And since batadv_bla_free() is\nalways setting it to NULL before it is (indirectly) called, it was never\nactually executed.\n\nBut the batadv_bla_purge_claims() -\u003e batadv_handle_unclaim() is at the\nmoment too fragile because the BLA code is not handling the rehashing in\nbatadv_bla_update_orig_address(). The stored backbone address doesn\u0027t have\nto be the one actually used for the hash bucket selection during the\ninitial adding of the backbone. The batadv_handle_unclaim() can therefore\nfail to find the respective backbone for the unclaim and then stop the\ndeletion.\n\nBut the actual backbone_gw object is not needed for the unclaim because all\nrelevant information is always provided by the caller. And the check for\nthe existence of the backbone_gw doesn\u0027t provide any additional security\ncheck for the deletion of a claim."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-16T10:32:34.089Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/844a95a734f178d56c7acce14c5cce2cecff7e1a"
        },
        {
          "url": "https://git.kernel.org/stable/c/baeb1a28fd8e2f68193650d3664a8cd1adfd85c6"
        },
        {
          "url": "https://git.kernel.org/stable/c/aacffa780a37e06cd5a13d33740a6e96c3a67e6c"
        },
        {
          "url": "https://git.kernel.org/stable/c/76aedcde5a2489cc971d4d1e396e784a49565e96"
        },
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          "url": "https://git.kernel.org/stable/c/f50edb69082a8ba990cc23d642089829f99afe6a"
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        },
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          "url": "https://git.kernel.org/stable/c/9a0c47023d3254048a1588534755d4476bcc3abc"
        },
        {
          "url": "https://git.kernel.org/stable/c/8d128c932bced74e3b1625ba3d7c78ef122a88a7"
        }
      ],
      "title": "batman-adv: bla: fix freeing of claims on meshif deletion",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
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    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89948",
    "datePublished": "2026-09-16T10:32:34.089Z",
    "dateReserved": "2026-09-11T19:38:34.777Z",
    "dateUpdated": "2026-09-16T10:32:34.089Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "microsoft_vex": {
      "current_release_date": "2026-09-17T01:16:06.000Z",
      "cve": "CVE-2026-89948",
      "id": "msrc_CVE-2026-89948",
      "initial_release_date": "2026-09-17T01:16:06.000Z",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "batman-adv: bla: fix freeing of claims on meshif deletion",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89948.json",
      "version": "1"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-89948\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-16T11:17:04.890\",\"lastModified\":\"2026-09-16T11:17:04.890\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nbatman-adv: bla: fix freeing of claims on meshif deletion\\n\\nWhen the mesh interface is getting deleted, then\\nbatadv_bla_del_backbone_claims() (via batadv_bla_purge_backbone_gw()) could\\nmake sure that all claims gets removed. But this function is only executed\\nwhen bat_priv-\u003ebla.claim_hash is not NULL. And since batadv_bla_free() is\\nalways setting it to NULL before it is (indirectly) called, it was never\\nactually executed.\\n\\nBut the batadv_bla_purge_claims() -\u003e batadv_handle_unclaim() is at the\\nmoment too fragile because the BLA code is not handling the rehashing in\\nbatadv_bla_update_orig_address(). The stored backbone address doesn\u0027t have\\nto be the one actually used for the hash bucket selection during the\\ninitial adding of the backbone. The batadv_handle_unclaim() can therefore\\nfail to find the respective backbone for the unclaim and then stop the\\ndeletion.\\n\\nBut the actual backbone_gw object is not needed for the unclaim because all\\nrelevant information is always provided by the caller. And the check for\\nthe existence of the backbone_gw doesn\u0027t provide any additional security\\ncheck for the deletion of a claim.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/batman-adv/bridge_loop_avoidance.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"23721387c409087fd3b97e274f34d3ddc0970b74\",\"lessThan\":\"844a95a734f178d56c7acce14c5cce2cecff7e1a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23721387c409087fd3b97e274f34d3ddc0970b74\",\"lessThan\":\"baeb1a28fd8e2f68193650d3664a8cd1adfd85c6\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23721387c409087fd3b97e274f34d3ddc0970b74\",\"lessThan\":\"aacffa780a37e06cd5a13d33740a6e96c3a67e6c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23721387c409087fd3b97e274f34d3ddc0970b74\",\"lessThan\":\"76aedcde5a2489cc971d4d1e396e784a49565e96\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23721387c409087fd3b97e274f34d3ddc0970b74\",\"lessThan\":\"f50edb69082a8ba990cc23d642089829f99afe6a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23721387c409087fd3b97e274f34d3ddc0970b74\",\"lessThan\":\"871acdf97f64cee8398f72b88b89e8b4f4816dbe\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23721387c409087fd3b97e274f34d3ddc0970b74\",\"lessThan\":\"9a0c47023d3254048a1588534755d4476bcc3abc\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"23721387c409087fd3b97e274f34d3ddc0970b74\",\"lessThan\":\"8d128c932bced74e3b1625ba3d7c78ef122a88a7\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/batman-adv/bridge_loop_avoidance.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3.5\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"3.5\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.270\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.221\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.188\",\"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-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/76aedcde5a2489cc971d4d1e396e784a49565e96\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/844a95a734f178d56c7acce14c5cce2cecff7e1a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/871acdf97f64cee8398f72b88b89e8b4f4816dbe\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8d128c932bced74e3b1625ba3d7c78ef122a88a7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9a0c47023d3254048a1588534755d4476bcc3abc\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/aacffa780a37e06cd5a13d33740a6e96c3a67e6c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/baeb1a28fd8e2f68193650d3664a8cd1adfd85c6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f50edb69082a8ba990cc23d642089829f99afe6a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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