{
  "cveId": "CVE-2026-68163",
  "url": "https://patchblox.com/security/cve/CVE-2026-68163",
  "summary": "CVE-2026-68163 is fixed in linux on 1 platform by DEBIAN-CVE-2026-68163 (version 7.1.6-1), released August 11, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  mm/page_vma_mapped: fix device-private PMD handl...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  mm/page_vma_mapped: fix device-private PMD handling  Commit 65edfda6f3f2 (\u0022mm/rmap: extend rmap and migration support device-private entries\u0022) introduced the concept of device-private PMD entries, but did not correctly update the rmap walk code to account for them.  As a result, when page_vma_mapped_walk() encounters device-private PMD entries, it takes no action other than to acquire the PMD lock and exit.  However this is highly problematic for two reasons - firstly, device private entries possess a PFN so check_pmd() needs to be called to ensure an overlapping PFN range.  Secondly, and more importantly, if PVMW_MIGRATION is set the caller assumes the returned entry is a migration entry, resulting in memory corruption when the caller tries to interpret the device private entry as such.  In addition, commit 146287290023 (\u0022mm/huge_memory: implement device-private THP splitting\u0022) allowed device private PMDs to be split like THP mappings, but again did not update this code path.  As a result, we might race a PMD split prior to acquiring the PMD lock.  This patch addresses all of these issues by invoking check_pmd(), ensuring PMVW_MIGRATION is not set and checks whether a split raced us we do for PMD THP and migration entries.  Instead of checking for a subset of the cases after taking the pmd_lock(), put device-private along with pmd_trans_huge() and pmd_is_migration_entry().  Also remove thp_migration_supported() as it is already guarded by pmd_is_migration_entry().  [akpm@linux-foundation.org: fix Raspberry Pi 1 build, per David]",
  "published": "2026-08-10T13:20:02Z",
  "severity": "high",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00165,
  "epssPercentile": 0.05786,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.1.6-1",
      "fix": "DEBIAN-CVE-2026-68163",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-68163",
      "released": "2026-08-11T16:03:09Z"
    }
  ],
  "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"
  }
}