{
  "threat_severity" : "Moderate",
  "public_date" : "2025-02-12T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: mm: clear uffd-wp PTE/PMD state on mremap()",
    "id" : "2345240",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2345240"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-20",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nmm: clear uffd-wp PTE/PMD state on mremap()\nWhen mremap()ing a memory region previously registered with userfaultfd as\nwrite-protected but without UFFD_FEATURE_EVENT_REMAP, an inconsistency in\nflag clearing leads to a mismatch between the vma flags (which have\nuffd-wp cleared) and the pte/pmd flags (which do not have uffd-wp\ncleared).  This mismatch causes a subsequent mprotect(PROT_WRITE) to\ntrigger a warning in page_table_check_pte_flags() due to setting the pte\nto writable while uffd-wp is still set.\nFix this by always explicitly clearing the uffd-wp pte/pmd flags on any\nsuch mremap() so that the values are consistent with the existing clearing\nof VM_UFFD_WP.  Be careful to clear the logical flag regardless of its\nphysical form; a PTE bit, a swap PTE bit, or a PTE marker.  Cover PTE,\nhuge PMD and hugetlb paths." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2025-11-11T00:00:00Z",
    "advisory" : "RHSA-2025:20095",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.1",
    "package" : "kernel-0:6.12.0-124.8.1.el10_1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-11-11T00:00:00Z",
    "advisory" : "RHSA-2025:20518",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-611.5.1.el9_7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-11-11T00:00:00Z",
    "advisory" : "RHSA-2025:20518",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-611.5.1.el9_7"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Will not fix",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2025-21696\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-21696\nhttps://lore.kernel.org/linux-cve-announce/2025021259-CVE-2025-21696-2482@gregkh/T" ],
  "name" : "CVE-2025-21696",
  "csaw" : false
}