GHSA-9C2V-WHHQ-6G24

Vulnerability from github – Published: 2026-09-24 18:31 – Updated: 2026-10-03 12:31
VLAI
Details

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

btrfs: fix reloc root cleanup in merge_reloc_roots()

If the root we got has zero root refs in its root item, we are resetting the root's ->reloc_root without using barriers like we do everywhere else. Sashiko complained about this while reviewing another patch, and it's correct (see the Link tag below).

Also, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless the root points to the reloc root we have.

Fix this by using clear_reloc_root(), which issues the memory barrier after setting the root's ->reloc_root to NULL and before clearing the bit BTRFS_ROOT_DEAD_RELOC_TREE from the root.

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2026-93798"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-24T17:17:12Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix reloc root cleanup in merge_reloc_roots()\n\nIf the root we got has zero root refs in its root item, we are resetting\nthe root\u0027s -\u003ereloc_root without using barriers like we do everywhere else.\nSashiko complained about this while reviewing another patch, and it\u0027s\ncorrect (see the Link tag below).\n\nAlso, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless\nthe root points to the reloc root we have.\n\nFix this by using clear_reloc_root(), which issues the memory barrier\nafter setting the root\u0027s -\u003ereloc_root to NULL and before clearing the bit\nBTRFS_ROOT_DEAD_RELOC_TREE from the root.",
  "id": "GHSA-9c2v-whhq-6g24",
  "modified": "2026-10-03T12:31:09Z",
  "published": "2026-09-24T18:31:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93798"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0bc25f0a2d1b3e0a691431c4d7aef36afcd527c5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/29531470b1bf1e8bd2df4941fe913106edbca615"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/415f8665a969d3c906e4fd7c90fcbb4b357886f6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/63d6b1f04cd91c825329712aa526215ffa5d11ca"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ab48583aa9948205ff9a6470e23dbff74c565e24"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b78fe9563e2d5ae47805f1e5dc722c91fd30e1f8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ee695a968aa73b1e67ccbf2133dc0e54381d32b2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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