GHSA-5V2W-FX47-6RQ2

Vulnerability from github – Published: 2025-02-27 03:34 – Updated: 2025-11-03 21:33
VLAI
Details

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]

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2025-21781"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-02-27T03:15:18Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: fix panic during interface removal\n\nReference counting is used to ensure that\nbatadv_hardif_neigh_node and batadv_hard_iface\nare not freed before/during\nbatadv_v_elp_throughput_metric_update work is\nfinished.\n\nBut there isn\u0027t a guarantee that the hard if will\nremain associated with a soft interface up until\nthe work is finished.\n\nThis fixes a crash triggered by reboot that looks\nlike this:\n\nCall trace:\n batadv_v_mesh_free+0xd0/0x4dc [batman_adv]\n batadv_v_elp_throughput_metric_update+0x1c/0xa4\n process_one_work+0x178/0x398\n worker_thread+0x2e8/0x4d0\n kthread+0xd8/0xdc\n ret_from_fork+0x10/0x20\n\n(the batadv_v_mesh_free call is misleading,\nand does not actually happen)\n\nI was able to make the issue happen more reliably\nby changing hardif_neigh-\u003ebat_v.metric_work work\nto be delayed work. This allowed me to track down\nand confirm the fix.\n\n[sven@narfation.org: prevent entering batadv_v_elp_get_throughput without\n soft_iface]",
  "id": "GHSA-5v2w-fx47-6rq2",
  "modified": "2025-11-03T21:33:01Z",
  "published": "2025-02-27T03:34:06Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-21781"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/072b2787321903287a126c148e8db87dd7ef96fe"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/167422a07096a6006599067c8b55884064fa0b72"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2c3fb7df4cc6d043f70d4a8a10f8b915bbfb75e7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/522b1596ea19e327853804da2de60aeb9c5d6f42"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7eb5dd201695645af071592a50026eb780081a72"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ccb7276a6d26d6f8416e315b43b45e15ee7f29e2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ce3f1545bf8fa28bd05ec113679e8e6cd23af577"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f0a16c6c79768180333f3e41ce63f32730e3c3af"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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