btrfs: fix hang during unmount when block group reclaim task is running

{
  "id": "f3017032030985871bb1969aa16e094ccf4b7a069b5b4ed1e23563f2ed3d2605",
  "url": "https://osv.dev/vulnerability/CVE-2022-49702",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "btrfs: fix hang during unmount when block group reclaim task is running",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: btrfs: fix hang during unmount when block group reclaim task is running When we start an unmount, at close_ctree(), if we have the reclaim task running and in the middle of a data block group relocation, we can trigger a deadlock when stopping an async reclaim task, producing a trace like the following: [629724.498185] task:kworker/u16:7 state:D stack: 0 pid:681170 ppid: 2 flags:0x00004000 [629724.499760] Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs] [629724.501267] Call Trace: [629724.501759] [629724.502174] __schedule+0x3cb/0xed0 [629724.502842] schedule+0x4e/0xb0 [629724.503447] btrfs_wait_on_delayed_iputs+0x7c/0xc0 [btrfs] [629724.504534] ? prepare_to_wait_exclusive+0xc0/0xc0 [629724.505442] flush_space+0x423/0x630 [btrfs] [629724.506296] ? rcu_read_unlock_trace_special+0x20/0x50 [629724.507259] ? lock_release+0x220/0x4a0 [629724.507932] ? btrfs_get_alloc_profile+0xb3/0x290 [btrfs] [629724.508940] ? do_raw_spin_unlock+0x4b/0xa0 [629724.509688] btrfs_async_reclaim_metadata_space+0x139/0x320 [btrfs] [629724.510922] process_one_work+0x252/0x5a0 [629724.511694] ? process_one_work+0x5a0/0x5a0 [629724.512508] worker_thread+0x52/0x3b0 [629724.513220] ? process_one_work+0x5a0/0x5a0 [629724.514021] kthread+0xf2/0x120 [629724.514627] ? kthread_complete_and_exit+0x20/0x20 [629724.515526] ret_from_fork+0x22/0x30 [629724.516236] [629724.516694] task:umount state:D stack: 0 pid:719055 ppid:695412",
    "evidence": "osv:CVE-2022-49702",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.15.51",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.18.8",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2022-49702",
      "aliases": [
        "CVE-2022-49702"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "18bb8bbf13c1839b43c9e09e76d397b753989af2"
                },
                {
                  "fixed": "341d33128a940c6634175dcb6ca92dc454cfa7d2"
                },
                {
                  "fixed": "9fadb11f1295289e0da4d3342ecb6b92c1c99540"
                },
                {
                  "fixed": "31e70e527806c546a72262f2fc3d982ee23c42d3"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49702.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.13.0"
                },
                {
                  "fixed": "5.15.51"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "5.18.8"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49702.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:40.274846783Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/31e70e527806c546a72262f2fc3d982ee23c42d3",
        "https://git.kernel.org/stable/c/341d33128a940c6634175dcb6ca92dc454cfa7d2",
        "https://git.kernel.org/stable/c/9fadb11f1295289e0da4d3342ecb6b92c1c99540",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49702.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2022-49702",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49702.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2022-49702",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 507890,
  "published_at": "2025-02-26T02:24:22.03+00:00"
}