batman-adv: fix panic during interface removal

{
  "id": "4e586851c3360f35505745c906dfa2306706d0d7dbff2d824f2ddb8434db08e6",
  "url": "https://osv.dev/vulnerability/CVE-2025-21781",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "batman-adv: fix panic during interface removal",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: batman-adv: fix panic during interface removal Reference counting is used to ensure that batadv_hardif_neigh_node and batadv_hard_iface are not freed before/during batadv_v_elp_throughput_metric_update work is finished. But there isn't a guarantee that the hard if will remain associated with a soft interface up until the work is finished. This fixes a crash triggered by reboot that looks like this: Call trace: batadv_v_mesh_free+0xd0/0x4dc [batman_adv] batadv_v_elp_throughput_metric_update+0x1c/0xa4 process_one_work+0x178/0x398 worker_thread+0x2e8/0x4d0 kthread+0xd8/0xdc ret_from_fork+0x10/0x20 (the batadv_v_mesh_free call is misleading, and does not actually happen) I was able to make the issue happen more reliably by changing hardif_neigh->bat_v.metric_work work to be delayed work. This allowed me to track down and confirm the fix. [sven@narfation.org: prevent entering batadv_v_elp_get_throughput without soft_iface]",
    "evidence": "osv:CVE-2025-21781",
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    "severity": "unknown",
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      "modified": "2026-10-28T02:30:37.285496442Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/072b2787321903287a126c148e8db87dd7ef96fe",
        "https://git.kernel.org/stable/c/167422a07096a6006599067c8b55884064fa0b72",
        "https://git.kernel.org/stable/c/2c3fb7df4cc6d043f70d4a8a10f8b915bbfb75e7",
        "https://git.kernel.org/stable/c/522b1596ea19e327853804da2de60aeb9c5d6f42",
        "https://git.kernel.org/stable/c/7eb5dd201695645af071592a50026eb780081a72",
        "https://git.kernel.org/stable/c/ccb7276a6d26d6f8416e315b43b45e15ee7f29e2",
        "https://git.kernel.org/stable/c/ce3f1545bf8fa28bd05ec113679e8e6cd23af577",
        "https://git.kernel.org/stable/c/f0a16c6c79768180333f3e41ce63f32730e3c3af",
        "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html",
        "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21781.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-21781",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
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        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21781.json"
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    "related_cves": [
      {
        "value": "CVE-2025-21781",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 504553,
  "published_at": "2025-02-27T02:18:24.013+00:00"
}