{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "8c2090c504e998c8f34ec870bae71dafcc96a6e0"
            },
            {
              "fixed": "e0b14bf06393be137d3efb6a3b7cd5b4b9810a6b"
            },
            {
              "fixed": "c44198f25fdfecc0ec0fe366bf8a47fe17d8e229"
            },
            {
              "fixed": "05ab9ec5dc24f234e0a2fecf3e6ff937c68f7d81"
            },
            {
              "fixed": "b06ccbabe2506fd70b9167a644978b049150224a"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.12.0"
            },
            {
              "fixed": "6.12.78"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.20"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43392.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Fix starvation of scx_enable() under fair-class saturation\n\nDuring scx_enable(), the READY -\u003e ENABLED task switching loop changes the\ncalling thread's sched_class from fair to ext. Since fair has higher\npriority than ext, saturating fair-class workloads can indefinitely starve\nthe enable thread, hanging the system. This was introduced when the enable\npath switched from preempt_disable() to scx_bypass() which doesn't protect\nagainst fair-class starvation. Note that the original preempt_disable()\nprotection wasn't complete either - in partial switch modes, the calling\nthread could still be starved after preempt_enable() as it may have been\nswitched to ext class.\n\nFix it by offloading the enable body to a dedicated system-wide RT\n(SCHED_FIFO) kthread which cannot be starved by either fair or ext class\ntasks. scx_enable() lazily creates the kthread on first use and passes the\nops pointer through a struct scx_enable_cmd containing the kthread_work,\nthen synchronously waits for completion.\n\nThe workfn runs on a different kthread from sch-\u003ehelper (which runs\ndisable_work), so it can safely flush disable_work on the error path\nwithout deadlock.",
  "id": "CVE-2026-43392",
  "modified": "2026-07-15T01:49:03.752457270Z",
  "published": "2026-05-08T14:21:36.692Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/05ab9ec5dc24f234e0a2fecf3e6ff937c68f7d81"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b06ccbabe2506fd70b9167a644978b049150224a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c44198f25fdfecc0ec0fe366bf8a47fe17d8e229"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e0b14bf06393be137d3efb6a3b7cd5b4b9810a6b"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43392.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43392"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "sched_ext: Fix starvation of scx_enable() under fair-class saturation"
}