CVE-2026-31657 (GCVE-0-2026-31657)
Vulnerability from cvelistv5
Published
2026-04-24 14:45
Modified
2026-04-27 14:04
Severity ?
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by reference batadv_bla_add_claim() can replace claim->backbone_gw and drop the old gateway's last reference while readers still follow the pointer. The netlink claim dump path dereferences claim->backbone_gw->orig and takes claim->backbone_gw->crc_lock without pinning the underlying backbone gateway. batadv_bla_check_claim() still has the same naked pointer access pattern. Reuse batadv_bla_claim_get_backbone_gw() in both readers so they operate on a stable gateway reference until the read-side work is complete. This keeps the dump and claim-check paths aligned with the lifetime rules introduced for the other BLA claim readers.
References
Impacted products
Vendor Product Version
Linux Linux Version: 23721387c409087fd3b97e274f34d3ddc0970b74
Version: 23721387c409087fd3b97e274f34d3ddc0970b74
Version: 23721387c409087fd3b97e274f34d3ddc0970b74
Version: 23721387c409087fd3b97e274f34d3ddc0970b74
Version: 23721387c409087fd3b97e274f34d3ddc0970b74
Version: 23721387c409087fd3b97e274f34d3ddc0970b74
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      "cpeApplicability": [
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: hold claim backbone gateways by reference\n\nbatadv_bla_add_claim() can replace claim-\u003ebackbone_gw and drop the old\ngateway\u0027s last reference while readers still follow the pointer.\n\nThe netlink claim dump path dereferences claim-\u003ebackbone_gw-\u003eorig and\ntakes claim-\u003ebackbone_gw-\u003ecrc_lock without pinning the underlying\nbackbone gateway. batadv_bla_check_claim() still has the same naked\npointer access pattern.\n\nReuse batadv_bla_claim_get_backbone_gw() in both readers so they operate\non a stable gateway reference until the read-side work is complete.\nThis keeps the dump and claim-check paths aligned with the lifetime\nrules introduced for the other BLA claim readers."
        }
      ],
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            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
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      "providerMetadata": {
        "dateUpdated": "2026-04-27T14:04:44.948Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f4858832ddef2f39f21e30b7226bbcd3c4b2bc96"
        },
        {
          "url": "https://git.kernel.org/stable/c/2f55b58b5a0bbed192d60c444a45a49cdf1b545f"
        },
        {
          "url": "https://git.kernel.org/stable/c/7962b522222628596ca9ecc8722efc95367aadbd"
        },
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          "url": "https://git.kernel.org/stable/c/4dee4c0688443aaf5bbec74aa203c851d1d53c35"
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          "url": "https://git.kernel.org/stable/c/1f2dc36c297d27733f1b380ea644cf15a361bd7b"
        },
        {
          "url": "https://git.kernel.org/stable/c/82d8701b2c930d0e96b0dbc9115a218d791cb0d2"
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      "title": "batman-adv: hold claim backbone gateways by reference",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31657",
    "datePublished": "2026-04-24T14:45:08.867Z",
    "dateReserved": "2026-03-09T15:48:24.129Z",
    "dateUpdated": "2026-04-27T14:04:44.948Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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}


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