{
  "cveId": "CVE-2021-47214",
  "url": "https://patchblox.com/security/cve/CVE-2021-47214",
  "summary": "CVE-2021-47214 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47214, released April 10, 2024. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  hugetlb, userfaultfd: fix reservation restore on...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  hugetlb, userfaultfd: fix reservation restore on userfaultfd error  Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we bail out using \u0022goto out_release_unlock;\u0022 in the cases where idx \u003E= size, or !huge_pte_none(), the code will detect that new_pagecache_page == false, and so call restore_reserve_on_error().  In this case I see restore_reserve_on_error() delete the reservation, and the following call to remove_inode_hugepages() will increment h-\u003Eresv_hugepages causing a 100% reproducible leak.  We should treat the is_continue case similar to adding a page into the pagecache and set new_pagecache_page to true, to indicate that there is no reservation to restore on the error path, and we need not call restore_reserve_on_error().  Rename new_pagecache_page to page_in_pagecache to make that clear.",
  "published": "2024-04-10T19:15:48Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00193,
  "epssPercentile": 0.09084,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.15.5-1",
      "fix": "DEBIAN-CVE-2021-47214",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47214",
      "released": "2024-04-10T19:15:48Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.15.5-1",
      "fix": "DEBIAN-CVE-2021-47214",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47214",
      "released": "2024-04-10T19:15:48Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "5.15.5-1",
      "fix": "DEBIAN-CVE-2021-47214",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47214",
      "released": "2024-04-10T19:15:48Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}