ghsa-mf47-w2f7-gc7f
Vulnerability from github
Published
2024-11-19 03:31
Modified
2025-11-04 00:32
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Details

In the Linux kernel, the following vulnerability has been resolved:

btrfs: reinitialize delayed ref list after deleting it from the list

At insert_delayed_ref() if we need to update the action of an existing ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's ref_add_list using list_del(), which leaves the ref's add_list member not reinitialized, as list_del() sets the next and prev members of the list to LIST_POISON1 and LIST_POISON2, respectively.

If later we end up calling drop_delayed_ref() against the ref, which can happen during merging or when destroying delayed refs due to a transaction abort, we can trigger a crash since at drop_delayed_ref() we call list_empty() against the ref's add_list, which returns false since the list was not reinitialized after the list_del() and as a consequence we call list_del() again at drop_delayed_ref(). This results in an invalid list access since the next and prev members are set to poison pointers, resulting in a splat if CONFIG_LIST_HARDENED and CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences otherwise.

So fix this by deleting from the list with list_del_init() instead.

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{
  "affected": [],
  "aliases": [
    "CVE-2024-50273"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-908"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-11-19T02:16:29Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: reinitialize delayed ref list after deleting it from the list\n\nAt insert_delayed_ref() if we need to update the action of an existing\nref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head\u0027s\nref_add_list using list_del(), which leaves the ref\u0027s add_list member\nnot reinitialized, as list_del() sets the next and prev members of the\nlist to LIST_POISON1 and LIST_POISON2, respectively.\n\nIf later we end up calling drop_delayed_ref() against the ref, which can\nhappen during merging or when destroying delayed refs due to a transaction\nabort, we can trigger a crash since at drop_delayed_ref() we call\nlist_empty() against the ref\u0027s add_list, which returns false since\nthe list was not reinitialized after the list_del() and as a consequence\nwe call list_del() again at drop_delayed_ref(). This results in an\ninvalid list access since the next and prev members are set to poison\npointers, resulting in a splat if CONFIG_LIST_HARDENED and\nCONFIG_DEBUG_LIST are set or invalid poison pointer dereferences\notherwise.\n\nSo fix this by deleting from the list with list_del_init() instead.",
  "id": "GHSA-mf47-w2f7-gc7f",
  "modified": "2025-11-04T00:32:03Z",
  "published": "2024-11-19T03:31:07Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-50273"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2fd0948a483e9cb2d669c7199bc620a21c97673d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/50a3933760b427759afdd23156a7280a19357a92"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/93c5b8decc0ef39ba84f4211d2db6da0a4aefbeb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bf0b0c6d159767c0d1c21f793950d78486690ee0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c24fa427fc0ae827b2a3a07f13738cbf82c3f851"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c9a75ec45f1111ef530ab186c2a7684d0a0c9245"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f04be6d68f715c1473a8422fc0460f57b5e99931"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.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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