{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "3f93aef535c8ea03e40cd8acf0753b3e6ed33e96"
            },
            {
              "fixed": "d8f57049521948df5f50797141472fbbed3b0723"
            },
            {
              "fixed": "0de9f31d447ae71ab08c7850a321682f8d2907c3"
            },
            {
              "fixed": "2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.1.0"
            },
            {
              "fixed": "6.18.53"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98079.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zstd: fix lost wakeup when waiting for a workspace\n\nA writer can sleep forever in zstd_get_workspace() even though a workspace\nis free.  When zstd_alloc_workspace() fails, the task is queued on\nzwsm-\u003ewait and schedules unconditionally, never re-testing the pool.\nzstd_put_workspace() publishes the workspace and then calls cond_wake_up(),\nwhich only wakes when a sleeper is already visible, so a workspace returned\nbetween the failed allocation and prepare_to_wait() wakes nobody.  The\nwindow is wide: zstd_alloc_workspace() goes through kvmalloc() and may\nenter reclaim.\n\nOnly a max level workspace triggers the wakeup and one is deliberately kept\nallocated as the fallback every waiter waits for, so once its wakeup is\nlost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens\nto return one.  Re-check the pool after prepare_to_wait() has published the\nwaiter, and use the workspace if one turned up.",
  "id": "CVE-2026-98079",
  "modified": "2026-09-27T03:30:43.252734279Z",
  "published": "2026-09-25T10:24:16.892Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0de9f31d447ae71ab08c7850a321682f8d2907c3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d8f57049521948df5f50797141472fbbed3b0723"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98079.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98079"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "btrfs: zstd: fix lost wakeup when waiting for a workspace"
}