ghsa-95w3-8433-6jf6
Vulnerability from github
Published
2025-01-08 18:30
Modified
2025-11-03 21:32
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:

quota: flush quota_release_work upon quota writeback

One of the paths quota writeback is called from is:

freeze_super() sync_filesystem() ext4_sync_fs() dquot_writeback_dquots()

Since we currently don't always flush the quota_release_work queue in this path, we can end up with the following race:

  1. dquot are added to releasing_dquots list during regular operations.
  2. FS Freeze starts, however, this does not flush the quota_release_work queue.
  3. Freeze completes.
  4. Kernel eventually tries to flush the workqueue while FS is frozen which hits a WARN_ON since transaction gets started during frozen state:

ext4_journal_check_start+0x28/0x110 [ext4] (unreliable) __ext4_journal_start_sb+0x64/0x1c0 [ext4] ext4_release_dquot+0x90/0x1d0 [ext4] quota_release_workfn+0x43c/0x4d0

Which is the following line:

WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);

Which ultimately results in generic/390 failing due to dmesg noise. This was detected on powerpc machine 15 cores.

To avoid this, make sure to flush the workqueue during dquot_writeback_dquots() so we dont have any pending workitems after freeze.

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{
  "affected": [],
  "aliases": [
    "CVE-2024-56780"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-01-08T18:15:18Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nquota: flush quota_release_work upon quota writeback\n\nOne of the paths quota writeback is called from is:\n\nfreeze_super()\n  sync_filesystem()\n    ext4_sync_fs()\n      dquot_writeback_dquots()\n\nSince we currently don\u0027t always flush the quota_release_work queue in\nthis path, we can end up with the following race:\n\n 1. dquot are added to releasing_dquots list during regular operations.\n 2. FS Freeze starts, however, this does not flush the quota_release_work queue.\n 3. Freeze completes.\n 4. Kernel eventually tries to flush the workqueue while FS is frozen which\n    hits a WARN_ON since transaction gets started during frozen state:\n\n  ext4_journal_check_start+0x28/0x110 [ext4] (unreliable)\n  __ext4_journal_start_sb+0x64/0x1c0 [ext4]\n  ext4_release_dquot+0x90/0x1d0 [ext4]\n  quota_release_workfn+0x43c/0x4d0\n\nWhich is the following line:\n\n  WARN_ON(sb-\u003es_writers.frozen == SB_FREEZE_COMPLETE);\n\nWhich ultimately results in generic/390 failing due to dmesg\nnoise. This was detected on powerpc machine 15 cores.\n\nTo avoid this, make sure to flush the workqueue during\ndquot_writeback_dquots() so we dont have any pending workitems after\nfreeze.",
  "id": "GHSA-95w3-8433-6jf6",
  "modified": "2025-11-03T21:32:05Z",
  "published": "2025-01-08T18:30:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-56780"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3e6ff207cd5bd924ad94cd1a7c633bcdac0ba1cb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6f3821acd7c3143145999248087de5fb4b48cf26"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8ea87e34792258825d290f4dc5216276e91cb224"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a5abba5e0e586e258ded3e798fe5f69c66fec198"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ab6cfcf8ed2c7496f55d020b65b1d8cd55d9a2cb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ac6f420291b3fee1113f21d612fa88b628afab5b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bcacb52a985f1b6d280f698a470b873dfe52728a"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/03/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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