{
  "cveId": "CVE-2024-49873",
  "url": "https://patchblox.com/security/cve/CVE-2024-49873",
  "summary": "CVE-2024-49873 is fixed in linux on 1 platform, first by DEBIAN-CVE-2024-49873, released October 21, 2024. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  mm/filemap: fix filemap_get_folios_contig THP pa...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  mm/filemap: fix filemap_get_folios_contig THP panic  Patch series \u0022memfd-pin huge page fixes\u0022.  Fix multiple bugs that occur when using memfd_pin_folios with hugetlb pages and THP.  The hugetlb bugs only bite when the page is not yet faulted in when memfd_pin_folios is called.  The THP bug bites when the starting offset passed to memfd_pin_folios is not huge page aligned.  See the commit messages for details.   This patch (of 5):  memfd_pin_folios on memory backed by THP panics if the requested start offset is not huge page aligned:  BUG: kernel NULL pointer dereference, address: 0000000000000036 RIP: 0010:filemap_get_folios_contig\u002B0xdf/0x290 RSP: 0018:ffffc9002092fbe8 EFLAGS: 00010202 RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000002  The fault occurs here, because xas_load returns a folio with value 2:      filemap_get_folios_contig()         for (folio = xas_load(\u0026xas); folio \u0026\u0026 xas.xa_index \u003C= end;                         folio = xas_next(\u0026xas)) {                 ...                 if (!folio_try_get(folio))   \u003C-- BOOM  \u00222\u0022 is an xarray sibling entry.  We get it because memfd_pin_folios does not round the indices passed to filemap_get_folios_contig to huge page boundaries for THP, so we load from the middle of a huge page range see a sibling.  (It does round for hugetlbfs, at the is_file_hugepages test).  To fix, if the folio is a sibling, then return the next index as the starting point for the next call to filemap_get_folios_contig.",
  "published": "2024-10-21T18:15:08Z",
  "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": 0.00202,
  "epssPercentile": 0.1018,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.11.4-1",
      "fix": "DEBIAN-CVE-2024-49873",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2024-49873",
      "released": "2024-10-21T18:15:08Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.11.4-1",
      "fix": "DEBIAN-CVE-2024-49873",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2024-49873",
      "released": "2024-10-21T18:15:08Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}