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batman-adv: hold claim backbone gateways by reference

Type: advisorySource: Official CVE List1 source record

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.

Announced Group revision 1
Original source ↗

CVE-2026-31657

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-31657

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "23721387c409087fd3b97e274f34d3ddc0970b74",
        "lessThan": "5202f071b367ffbc8e279fc7a00db14f5e587f52",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "23721387c409087fd3b97e274f34d3ddc0970b74",
        "lessThan": "69d1ce9c72eca91203ffdb8d08bacd511100aec6",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "23721387c409087fd3b97e274f34d3ddc0970b74",
        "lessThan": "f4858832ddef2f39f21e30b7226bbcd3c4b2bc96",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "23721387c409087fd3b97e274f34d3ddc0970b74",
        "lessThan": "2f55b58b5a0bbed192d60c444a45a49cdf1b545f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "23721387c409087fd3b97e274f34d3ddc0970b74",
        "lessThan": "7962b522222628596ca9ecc8722efc95367aadbd",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "23721387c409087fd3b97e274f34d3ddc0970b74",
        "lessThan": "4dee4c0688443aaf5bbec74aa203c851d1d53c35",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "23721387c409087fd3b97e274f34d3ddc0970b74",
        "lessThan": "1f2dc36c297d27733f1b380ea644cf15a361bd7b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "23721387c409087fd3b97e274f34d3ddc0970b74",
        "lessThan": "82d8701b2c930d0e96b0dbc9115a218d791cb0d2",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/batman-adv/bridge_loop_avoidance.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "3.5"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "3.5",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.258",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.209",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.169",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.135",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.82",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.23",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "6.19.13",
        "versionType": "semver",
        "lessThanOrEqual": "6.19.*"
      },
      {
        "status": "unaffected",
        "version": "7.0",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/batman-adv/bridge_loop_avoidance.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-31657

Source reference: /cveMetadata/cveId

Publisher severity

critical

Source reference: /containers/cna/metrics

Event
#39939 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement

Revision history

  1. CVE-2026-31657 · Revision 1Source updated